KR20240120636A - Organic light emitting diode and organic light emitting device including the same - Google Patents

Abstract

The present invention includes: a first electrode; a second electrode facing the first electrode; a first light emitting unit including a first hole transport layer and a first light emitting material layer, which is a blue light emitting material layer, and located between the first electrode and the second electrode; It includes a second light-emitting material layer including at least one of a red light-emitting material layer and a green light-emitting material layer and a second light-emitting portion located between the first light-emitting material and the second electrode, and the first hole transport layer includes: An organic light emitting diode including a high refractive index layer having a first refractive index and a low refractive index layer having a second refractive index less than the first refractive index and positioned between the high refractive index layer and the first light emitting material layer, and an organic light emitting device including the same to provide.

Description

Organic light emitting diode and organic light emitting device including the same {ORGANIC LIGHT EMITTING DIODE AND ORGANIC LIGHT EMITTING DEVICE INCLUDING THE SAME}

The present invention relates to organic light-emitting diodes, and more specifically, to organic light-emitting diodes with high blue light-emitting efficiency and improved color viewing angle, and organic light-emitting devices including the same.

Recently, as display devices have become larger, the demand for flat display devices that occupy less space has increased. As one of these flat display devices, the technology of organic light emitting devices, including organic light emitting diodes (OLEDs), is rapidly developing. is developing.

An organic light-emitting diode is a device that emits light when electrons and holes are injected from the cathode and anode into the light-emitting material layer formed between the electron injection electrode (cathode) and the hole injection electrode (anode), the electrons and holes pair and then disappear. Not only can devices be formed on flexible transparent substrates such as plastic, but they also have the advantage of being able to be driven at low voltages (less than 10V), consuming relatively little power, and providing excellent color.

Recently, a white organic light emitting diode including a blue light emitting material layer, a red light emitting material layer, and a green light emitting material layer has been proposed. However, the blue light-emitting material layer has a lower luminous efficiency than each of the red and green light-emitting material layers, so there is a problem in that the color temperature and luminance of the white organic light-emitting diode are lowered. Additionally, when the position of the light emitting material layer is adjusted to increase blue efficiency, a problem occurs in which the color viewing angle of the white organic light emitting diode is deteriorated.

The present invention aims to solve problems in blue luminance and color viewing angle in conventional organic light-emitting diodes.

In order to solve the above problems, the present invention includes a first electrode; a second electrode facing the first electrode; a first light emitting unit including a first hole transport layer and a first light emitting material layer, which is a blue light emitting material layer, and located between the first electrode and the second electrode; It includes a second light-emitting material layer including at least one of a red light-emitting material layer and a green light-emitting material layer and a second light-emitting portion located between the first light-emitting material and the second electrode, and the first hole transport layer includes: An organic light emitting diode is provided including a high refractive index layer having a first refractive index and a low refractive index layer having a second refractive index less than the first refractive index and positioned between the high refractive index layer and the first light emitting material layer.

In the organic light emitting diode of the present invention, the difference between the first refractive index and the second refractive index is 0.05 or more.

In the organic light emitting diode of the present invention, the high refractive index layer includes at least one of the compound represented by Formula 1 and the compound represented by Formula 2, and the low refractive index layer includes a compound represented by Formula 2 and a compound represented by Formula 3. It is characterized in that it contains at least one of a compound, a compound represented by Formula 4, and a compound represented by Formula 5.

[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

In the organic light emitting diode of the present invention, the low refractive index layer includes at least one of the compound represented by Formula 3, the compound represented by Formula 4, and the compound represented by Formula 5.

In the organic light emitting diode of the present invention, the high refractive index layer includes a compound represented by Formula 1 and a compound represented by Formula 2, and the weight ratio of the compound represented by Formula 1 is equal to the weight ratio of the compound represented by Formula 2 It is characterized by being equal to or greater than this.

In the organic light emitting diode of the present invention, the high refractive index layer has a first thickness, and the low refractive index layer has a second thickness greater than the first thickness.

In the organic light emitting diode of the present invention, the first thickness is 20 to 45% of the thickness of the first hole transport layer.

In the organic light emitting diode of the present invention, the second light emitting part further includes a second hole transport layer located below the second light emitting material layer, and the second hole transport layer has a single layer structure.

In the organic light emitting diode of the present invention, the refractive index of the hole transport material in the second hole transport layer is smaller than the first refractive index and greater than the second refractive index.

The organic light emitting diode of the present invention includes a third light emitting material layer, which is a blue light emitting material layer, and further includes a third light emitting portion located between the second light emitting portion and the second electrode, and the second light emitting material layer is characterized in that it includes the red light-emitting material layer and the green light-emitting material layer.

In the organic light-emitting diode of the present invention, the second light-emitting material layer further includes a yellow-green light-emitting material layer located between the red light-emitting material layer and the green light-emitting material layer.

In the organic light emitting diode of the present invention, the second light emitting unit further includes a second hole transport layer located below the second light emitting material layer, and the third light emitting unit includes a third hole transport layer located below the third light emitting material layer. It further includes a hole transport layer, and each of the second and third hole transport layers has a single-layer structure.

In the organic light emitting diode of the present invention, the refractive index of the hole transport material in the second hole transport layer and the refractive index of the hole transport material in the third hole transport layer are each smaller than the first refractive index and greater than the second refractive index. .

The organic light emitting diode of the present invention includes a third light emitting part that includes a third light emitting material layer, which is a blue light emitting material layer, and is located between the second light emitting part and the second electrode; It includes a fourth light-emitting material layer that is a red light-emitting material layer and a fourth light-emitting portion located between the first light-emitting portion and the first electrode, and the second light-emitting material layer includes a green light-emitting material layer. Do it as

In the organic light emitting diode of the present invention, the second light emitting unit further includes a second hole transport layer located below the second light emitting material layer, and the third light emitting unit includes a third hole transport layer located below the third light emitting material layer. It further includes a hole transport layer, and the fourth light emitting unit further includes a fourth hole transport layer located below the fourth light emitting material layer, and each of the second to fourth hole transport layers is characterized in that it has a single layer structure. .

In the organic light-emitting diode of the present invention, the refractive index of the hole transport material in the second hole transport layer, the refractive index of the hole transport material in the third hole transport layer, and the refractive index of the hole transport material in the fourth hole transport layer are each characterized in that they are smaller than the first refractive index and larger than the second refractive index.

In the organic light emitting diode of the present invention, the second light emitting material layer includes the red light emitting material layer and the green light emitting material layer, and the second light emitting material layer is between the red light emitting material layer and the green light emitting material layer. It is characterized in that it further includes a yellow-green light-emitting material layer located at.

From another perspective, the present invention includes a substrate; An organic light emitting device including the above-described organic light emitting diode located on the upper part of the substrate is provided.

The organic light emitting device of the present invention further includes a color filter layer positioned between the substrate and the organic light emitting diode.

In the organic light emitting diode of the present invention, the first hole transport layer adjacent to the first electrode, which is the anode, and located below the first light emitting material layer, which is the blue light emitting material layer, has a double layer structure including a high refractive index layer and a low refractive index layer, and Accordingly, the luminous efficiency of the organic light-emitting diode and the organic light-emitting device including the same increases, the color viewing angle is improved, and low-power operation is possible.

In addition, the high refractive index layer has a smaller thickness than the low refractive index layer, and thus the luminous efficiency of the organic light emitting diode and the organic light emitting device including the same is further increased and the color viewing angle is further improved.

1 is a schematic circuit diagram of an organic light emitting display device according to an embodiment of the present invention.
Figure 2 is a schematic cross-sectional view of an organic light emitting display device according to a first embodiment of the present invention.
Figure 3 is a schematic cross-sectional view of an organic light emitting diode according to a second embodiment of the present invention.
Figure 4 is a schematic cross-sectional view of an organic light-emitting diode according to a third embodiment of the present invention.
Figure 5 is a schematic cross-sectional view of an organic light-emitting diode according to a fourth embodiment of the present invention.
Figure 6 is a graph showing the EL (electroluminescence) spectrum of the organic light emitting diode of Comparative Example 1.
Figure 7 is a graph showing the EL spectrum of the organic light emitting diode of Comparative Example 2.
Figure 8 is a graph showing the EL spectrum of the organic light emitting diode of Comparative Example 3.
Figure 9 is a graph showing the EL spectrum of the organic light-emitting diode of Experimental Example 1.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms. These embodiments only serve to ensure that the disclosure of the present invention is complete and that common knowledge in the technical field to which the present invention pertains is not limited. It is provided to fully inform those who have the scope of the invention.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are illustrative, and the present invention is not limited to the matters shown. Like reference numerals refer to like elements throughout the specification. Additionally, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. When 'includes', 'has', 'consists of', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the plural is included unless specifically stated otherwise.

When interpreting a component, it is interpreted to include the margin of error even if there is no separate explicit description.

In the case of a description of a positional relationship, for example, if the positional relationship of two parts is described as 'on top', 'on the top', 'on the bottom', 'next to', etc., 'immediately' Alternatively, there may be one or more other parts placed between the two parts, unless 'directly' is used.

In the case of a description of a temporal relationship, for example, if a temporal relationship is described as 'after', 'successfully after', 'after', 'before', etc., 'immediately' or 'directly' Unless used, non-consecutive cases may also be included.

Although first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are merely used to distinguish one component from another. Accordingly, the first component mentioned below may also be the second component within the technical spirit of the present invention.

Each feature of the various embodiments of the present invention can be combined or combined with each other partially or entirely, and various technical interconnections and operations are possible, and each embodiment can be implemented independently of each other or together in a related relationship. It may be possible.

In the present invention, an organic light emitting device including an organic light emitting diode may be an organic light emitting display device or an organic light emitting lighting device. As an example, the description will focus on the organic light emitting display device, which is a display device including the organic light emitting diode of the present invention.

Hereinafter, preferred embodiments according to the present invention will be described with reference to the drawings.

1 is a schematic circuit diagram of an organic light emitting display device according to an embodiment of the present invention.

As shown in FIG. 1, in the organic light emitting display device, a gate wire (GL), a data wire (DL), and a power wire (PL) that intersect with each other to define the pixel area (P) are formed. ), a switching thin film transistor (Ts), a driving thin film transistor (Td), a storage capacitor (Cst), and an organic light emitting diode (D) are formed. The pixel area (P) may include, but is not limited to, a red pixel area, a green pixel area, and a blue pixel area. For example, the pixel area P may include a red pixel area, a green pixel area, a blue pixel area, and a white pixel area. The plurality of pixel areas P may be arranged in a matrix form or other form. The organic light emitting display device may further include components such as a timing controller, scan driver, data driver, and power source, and may be a flexible, bendable, or wearable display device and may include a touch function.

The switching thin film transistor (Ts) is connected to the gate wire (GL) and the data wire (DL), and the driving thin film transistor (Td) is connected between the switching thin film transistor (Ts) and the power wire (PL). The storage capacitor (Cst) is connected to the gate electrode and drain electrode of the driving thin film transistor (Td), and the organic light emitting diode (D) is connected to the driving thin film transistor (Td).

In such an organic light emitting display device, when the switching thin film transistor (Ts) is turned on according to a gate signal (e.g., scan signal) applied to the gate wire (GL, for example, scan wire), The data signal applied to the data line DL is applied to the gate electrode of the driving thin film transistor Td and one electrode of the storage capacitor Cst through the switching thin film transistor Ts.

The driving thin film transistor (Td) is turned on according to the data signal applied to the gate electrode, and as a result, a current proportional to the data signal flows from the power wiring (PL) through the driving thin film transistor (Td) to the organic light emitting diode (D). flows, and the organic light emitting diode (D) emits light with a luminance proportional to the current flowing through the driving thin film transistor (Td).

At this time, the storage capacitor Cst is charged with a voltage proportional to the data signal, so that the voltage of the gate electrode of the driving thin film transistor Td is maintained constant for one frame.

Therefore, the organic light emitting display device can display a desired image.

Figure 2 is a schematic cross-sectional view of an organic light emitting display device according to a first embodiment of the present invention.

As shown in FIG. 2, the organic light emitting display device 100 includes a substrate 110 having a red pixel region (RP), a green pixel region (GP), and a blue pixel region (BP) defined. Located between the thin film transistor (Tr) located at the top, the organic light emitting diode (D) located above the thin film transistor (Tr) and connected to the thin film transistor (Tr), and the organic light emitting diode (D) and the substrate 110. It includes a color filter layer 180.

The substrate 110 may be a glass substrate or a flexible substrate. For example, the substrate 110 may be a polyimide (PI) substrate, a polyethersulfone (PES) substrate, a polyethylenenaphthalate (PEN) substrate, a polyethylene terephthalate (PET) substrate, and a polyethersulfone (PES) substrate. It may be any one of carbonate (polycarbonate; PC) substrates.

A buffer layer 120 is formed on the substrate 110, and thin film transistors (Tr) are formed on the buffer layer 120 corresponding to each of the red pixel region (RP), green pixel region (GP), and blue pixel region (BP). do. The buffer layer 120 may be omitted, and in this case, the thin film transistor (Tr) may be located on the substrate 110.

A semiconductor layer 122 is formed on the buffer layer 120. For example, the semiconductor layer 122 may be made of an oxide semiconductor material. When the semiconductor layer 122 is made of an oxide semiconductor material, a light-shielding pattern (not shown) may be formed under the semiconductor layer 122. The light blocking pattern prevents light from being incident on the semiconductor layer 122 and prevents the semiconductor layer 122 from being deteriorated by light. Alternatively, the semiconductor layer 122 may be made of polycrystalline silicon, and in this case, both edges of the semiconductor layer 122 may be doped with impurities.

A gate insulating film 124 made of an insulating material is formed on the entire surface of the substrate 110 on top of the semiconductor layer 122. The gate insulating film 124 may be made of an inorganic insulating material such as silicon oxide (SiOx) or silicon nitride (SiNx).

A gate electrode 130 made of a conductive material such as metal is formed on the gate insulating film 124 corresponding to the center of the semiconductor layer 122. In FIG. 2, the gate insulating film 124 is formed on the entire surface of the substrate 110, but the gate insulating film 124 may be patterned to have the same shape as the gate electrode 130.

An interlayer insulating film 132 made of an insulating material is formed on the entire surface of the substrate 110 on the gate electrode 130. The interlayer insulating film 132 may be formed of an inorganic insulating material such as silicon oxide or silicon nitride, or may be formed of an organic insulating material such as benzocyclobutene or photo-acryl.

The interlayer insulating film 132 has first and second semiconductor layer contact holes 134 and 136 exposing upper surfaces of both sides of the semiconductor layer 122 . The first and second semiconductor layer contact holes 134 and 136 are located on both sides of the gate electrode 130 and spaced apart from the gate electrode 130 . In Figure 2, the first and second semiconductor layer contact holes 134 and 136 are formed in the interlayer insulating film 132 and the gate insulating film 124. In contrast, when the gate insulating film 124 is patterned to have the same shape as the gate electrode 130, the first and second semiconductor layer contact holes 134 and 136 can be formed only in the interlayer insulating film 132.

A source electrode 140 and a drain electrode 142 made of a conductive material such as metal are formed on the interlayer insulating film 132. The source electrode 140 and the drain electrode 142 are positioned spaced apart from each other around the gate electrode 130, and are connected to both sides of the semiconductor layer 122 through the first and second semiconductor layer contact holes 134 and 136, respectively. Contact.

The semiconductor layer 122, the gate electrode 130, the source electrode 140, and the drain electrode 142 form a thin film transistor (Tr), and the thin film transistor (Tr) may be n-type. In contrast, the thin film transistor (Tr) may be p-type. The thin film transistor (Tr) functions as a driving element. That is, the thin film transistor (Tr) is the driving thin film transistor (Td) of FIG. 1.

In FIG. 2 , the thin film transistor Tr has a coplanar structure in which the gate electrode 130, the source electrode 140, and the drain electrode 142 are located on the semiconductor layer 122. In contrast, the thin film transistor (Tr) may have an inverted staggered structure in which the gate electrode is located at the bottom of the semiconductor layer, and the source electrode and drain electrode are located at the top of the semiconductor layer. In this case, the semiconductor layer may be made of amorphous silicon.

Additionally, a color filter layer 180 is formed on the interlayer insulating film 132. The color filter layer 180 includes a red color filter 182, a green color filter 184, and a blue color filter 186 corresponding to the red pixel area (RP), green pixel area (GP), and blue pixel area (BP), respectively. Includes.

The red color filter 182 includes at least one of a red dye and a red pigment, the green color filter 184 includes at least one of a green dye and a green pigment, and the blue color filter 186 may include at least one of blue dye and blue pigment.

Although not shown, the gate wire and data wire intersect to define the pixel area, and a switching thin film transistor, which is a switching element connected to the gate wire and data wire, is further formed. The switching element is connected to the thin film transistor (Tr), which is the driving element. In addition, high-level voltage wiring and low-level voltage wiring are formed on the upper part of the substrate 110, and a storage capacitor may be further configured to maintain the voltage of the gate electrode of the thin film transistor (Tr) constant during one frame. .

A planarization layer 150 is formed on the entire surface of the substrate 110 on the color filter layer 180 and the thin film transistor (Tr). The planarization layer 150 has a flat top surface and has a drain contact hole 152 exposing the drain electrode 142 of the thin film transistor (Tr).

The organic light emitting diode (D) is located on the planarization layer 150 and includes a first electrode 210 connected to the drain electrode 142 of the thin film transistor (Tr), and an organic light emitting diode sequentially stacked on the first electrode 210. It includes a light emitting layer 220 and a second electrode 230. The organic light emitting diode (D) is located in each of the red pixel region (RP), green pixel region (GP), and blue pixel region (BP) and can emit white light.

The first electrode 210 is formed separately for each pixel region (RP, GP, BP). The first electrode 210 may be an anode and may be made of transparent conductive oxide (TCO) with a relatively large work function. The first electrode 210 may be a transparent electrode. For example, the first electrode 210 is made of indium-tin-oxide (ITO), indium-zinc-oxide (IZO), and indium-tin-zinc-oxide (indium). -tin-zinc oxide; ITZO), tin oxide (SnO), zinc oxide (ZnO), indium-copper-oxide (ICO), and aluminum:zinc oxide (Al:ZnO; AZO). there is.

Additionally, a bank layer 166 covering the edge of the first electrode 210 is formed on the planarization layer 150. The bank layer 166 exposes the center of the first electrode 210 corresponding to the pixel area. Since the organic light emitting diode (D) emits white light in the red, green, and blue pixel areas (RP, GP, and BP), the organic light emitting layer 220 is separated from the red, green, and blue pixel areas (RP, GP, and BP). It can be formed as a common layer without having to be. The bank layer 166 is formed to prevent current leakage at the edge of the first electrode 210, and the bank layer 166 may be omitted.

An organic light-emitting layer 220 is formed on the first electrode 210. The organic light-emitting layer 220 includes a first light-emitting part including a blue emitting material layer (EML) and a first hole transport layer, and at least one of a green light-emitting material layer and a red light-emitting material layer, and emits the first light. It includes a second light emitting unit located between the unit and the second electrode 230.

In one embodiment, the organic light-emitting layer 220 includes a blue light-emitting material layer and may further include a third light-emitting portion located between the second light-emitting portion and the second electrode 230.

In one embodiment, the second light emitting part includes a green light emitting material layer, and the organic light emitting layer 220 includes a blue light emitting material layer and a third light emitting part located between the second light emitting part and the second electrode 230. It may further include a fourth light emitting unit that includes a red light emitting material layer and is located between the first light emitting unit and the first electrode 210.

A second electrode 230 is formed on the substrate 110 on which the organic light emitting layer 220 is formed. The second electrode 230 is located in front of the display area and may include a metal material with excellent reflective properties. For example, the second electrode 230 may include a material selected from the group consisting of aluminum (Al), magnesium (Mg), calcium (Ca), silver (Ag), or alloys or combinations thereof.

In the organic light emitting diode (D) of the present invention, the first electrode 210 may be a transparent electrode, and the second electrode 230 may be a reflective electrode.

An encapsulation layer (or encapsulation film) may be formed on the second electrode 230 to prevent external moisture from penetrating into the organic light emitting diode (D). For example, the encapsulation layer may have a stacked structure of a first inorganic insulating layer, an organic insulating layer, and a second inorganic insulating layer, but is not limited to this.

Additionally, a metal plate may be further provided over the encapsulation layer.

Additionally, a polarizing plate may be attached to the outer surface of the substrate 110 to reduce external light reflection. For example, the polarizer may be a circular polarizer.

In Figure 2, the color filter layer 180 is disposed between the organic light emitting diode (D) and the interlayer insulating film 132. In contrast, the position of the color filter layer 180 is not limited between the organic light emitting diode (D) and the substrate 110.

Additionally, a color conversion layer (not shown) may be provided between the organic light emitting diode (D) and the color filter layer 180. The color conversion layer includes a red color conversion layer, a green color conversion layer, and a blue color conversion layer corresponding to each of the red pixel area (RP), green pixel area (GP), and blue pixel area (BP), and an organic light emitting diode ( White light from D) can be converted to red, green and blue respectively.

As described above, white light from the organic light emitting diode (D) is transmitted through the red color filter 182 and the green color filter corresponding to the red pixel region (RP), green pixel region (GP), and blue pixel region (BP), respectively. (184), by passing through the blue color filter 186, red, green and blue light is displayed in the red pixel area (RP), green pixel area (GP) and blue pixel area (BP).

Meanwhile, in Figure 2, an organic light emitting diode (D) that emits white light is used in a display device. In contrast, the organic light emitting diode (D) may be formed on the entire surface of the substrate without a driving element such as a thin film transistor (Tr) and the color filter layer 180 and may be used in a lighting device. In the present invention, organic light emitting devices include display devices and lighting devices.

Figure 3 is a schematic cross-sectional view of an organic light emitting diode according to a second embodiment of the present invention.

As shown in FIG. 3, the organic light emitting diode D1 includes a first electrode 210, a second electrode 230 facing the first electrode 210, the first electrode 210, and the second electrode ( 230), which includes an organic light-emitting layer 220 located between the organic light-emitting layer 220, a first hole transport layer 320 including a high refractive index layer 322 and a low refractive index layer 326, and a first hole transport layer 320 that is a blue light-emitting material layer. 1. It includes a first light emitting material layer 310 including a light emitting material layer 312, a second light emitting material layer 332 including a red light emitting material layer 332a and a green light emitting material layer 332b, and a first light emitting material layer 332. It includes a second light emitting unit 330 located between the light emitting unit 310 and the second electrode 230.

The organic light-emitting layer 220 may further include a charge generation layer 360 located between the first light-emitting part 310 and the second light-emitting part 330.

The organic light emitting display device 100 includes a red pixel area (RP), a green pixel area (GP), and a blue pixel area (BP), and the organic light emitting diode D1 includes a red pixel area (RP) and a green pixel area ( It is located in each of the blue pixel area (GP) and blue pixel area (BP) and emits white light.

In the first light emitting unit 310, the first hole transport layer 320 has a double-layer structure of a high refractive index layer 322 and a low refractive index layer 326, and the low refractive index layer 326 has a high refractive index layer 322 and the first It is located between the light emitting material layers 312. The low refractive index layer 326 may contact the high refractive index layer 322 and the first light emitting material layer 312.

The high refractive index layer 322 includes a first hole transport material 324 having a first refractive index, and the low refractive index layer 326 includes a second hole transport material 328 having a second refractive index less than the first refractive index. do. The difference between the first refractive index and the second refractive index may be 0.05 or more. In one embodiment, the difference between the first and second refractive indices may be 0.05 or more, 0.25 or less, preferably 0.09 or more, 0.25 or less, more preferably 0.1 or more, 0.25 or less, more preferably 0.15 or more, 0.25 or less. there is. For example, the first refractive index may range from 1.9 to 2.1, and the second refractive index may range from 1.7 to 1.9.

In one embodiment, the first hole transport material 324 may include at least one of a compound of Formula 1 and a compound of Formula 2, and the second hole transport material 328 may include a compound of Formula 2, a compound of Formula 3, It may include at least one of the compounds of Formula 4 and Formula 5.

[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

The refractive indices of the compounds shown in Formulas 1 to 5 were measured and listed in Table 1.

A 300 Å thick compound layer was formed by depositing the compound on a bare glass at a rate of 1.0 Å/s in a chamber under 1.0*10-6 torr conditions, and measuring the refractive index using an RC2 Ellipsometer (J.A Woollam) equipment. did. At this time, to obtain refractive index values for each wavelength, "psi" and "delta" values were measured at 5° intervals in the 210~1000nm wavelength range and at 50~70° angles. To increase the accuracy of the measured refractive index values, the values were measured at 5° intervals in the 210~1000nm wavelength range and at 50~70° angles. Transmittance was measured at 20° intervals in the ° range. The refractive index value was measured by modeling the measured “psi” and “delta” values. The refractive index value in Table 1 is the refractive index value at 450 nm.

[Table 1]

In one embodiment of the present invention, the first hole transport material 324 may be a compound of Formula 1. That is, the high refractive index layer 322 may be made only of the compound of Chemical Formula 1.

In one embodiment of the present invention, the first hole transport material 324 may include a compound of Formula 1 and a compound of Formula 2. In this case, the weight ratio of the compound of Formula 1 may be equal to or greater than the weight ratio of the compound of Formula 2. For example, the weight ratio of the compound of Formula 1 and the compound of Formula 2 may be 5:5 to 9:1, preferably 6:4, 7:3, or 8:2.

In one embodiment of the present invention, the second hole transport material 328 may include only the compound of Formula 3. That is, the low refractive index layer 326 may be made only of the compound of Chemical Formula 3.

In one embodiment of the present invention, the second hole transport material 328 may include only the compound of Formula 4. That is, the low refractive index layer 326 may be made only of the compound of Chemical Formula 4.

In one embodiment of the present invention, the second hole transport material 328 may include only the compound of Formula 5. That is, the low refractive index layer 326 may be made only of the compound of Chemical Formula 5.

In one embodiment of the present invention, the second hole transport material 328 may include at least two of the Formula 2 compound, the Formula 3 compound, the Formula 4 compound, and the Formula 5 compound.

In one embodiment of the present invention, the second hole transport material 328 may include a compound of Formula 2 and a compound of Formula 4. In this case, the weight ratio of the compound of Formula 2 and the weight ratio of the compound of Formula 4 may be the same or different. For example, the low refractive index layer 326 can be formed by co-depositing a compound of Chemical Formula 2 and a compound of Chemical Formula 4.

In one embodiment of the present invention, the second hole transport material 328 may include a compound of Chemical Formula 4 and a compound of Chemical Formula 5. In this case, the weight ratio of the compound of Formula 4 and the weight ratio of the compound of Formula 5 may be the same or different.

In one embodiment of the present invention, the second hole transport material 328 may include a compound of Formula 2 and a compound of Formula 5. In this case, the weight ratio of the compound of Formula 2 and the weight ratio of the compound of Formula 5 may be the same or different.

In one embodiment of the present invention, the first hole transport material 324 may include at least one of a compound of Formula 1 and a compound of Formula 2, and the second hole transport material 328 may include a compound of Formula 3, a compound of Formula 4, It may include at least one of the compounds of Formula 5.

The high refractive index layer 322 may have a first thickness t1, and the low refractive index layer 326 may have a second thickness t2 greater than the first thickness t1. The first thickness (t1) of the high refractive index layer 322 may be 10 to 49% of the thickness of the first hole transport layer 320, and the second thickness (t2) of the low refractive index layer 326 may be 10 to 49% of the thickness of the first hole transport layer 320. ) may be 51 to 90% of the thickness. In one embodiment, the first thickness t1 of the high refractive index layer 322 may be 20 to 45%, preferably 30 to 45%, of the thickness of the first hole transport layer 320.

In an embodiment of the present invention, the first thickness t1 is 200 Å, 225 Å, 250 Å, 275 Å, 300 Å, 325 Å, 350 Å, 375 Å, 400 Å, 425 Å, 450 Å, 475 Å, Or it may be 500 Å. In an embodiment of the present invention, the second thickness (t2) is 500 Å, 525 Å, 550 Å, 575 Å, 600 Å, 625 Å, 650 Å, 675 Å, 700 Å, 725 Å, 750 Å, 775 Å, Or it may be 800 Å. For example, the first thickness (t1) may be in the range of 200 to 500 Å, preferably 250 to 450 Å, 300 to 450 Å, 250 to 400 Å, or 300 to 400 Å, and the second thickness (t2) may be in the range of 500 to 800 Å. , preferably in the range of 500 to 750 Å, 550 to 750 Å, or 550 to 700 Å.

The first light emitting material layer 312 is a blue light emitting material layer and may include a blue host and a blue dopant. The blue dopant may include at least one of a fluorescent compound, a phosphorescent compound, and a delayed fluorescent compound. In one embodiment, the blue dopant can be a fluorescent compound.

For example, the blue host is 1,3-bis(carbazol-9-yl)benzene(mCP), 9-(3-(9H-carbazol-9-yl)phenyl)-9H-carbazole-3-carbonitrile (mCP) -CN), 3,3'-bis(N-carbazolyl)-1,1'-biphenyl(mCBP), CBP-CN, 9-(3-(9H-Carbazol-9-yl)phenyl)-3-( diphenylphosphoryl)-9H-carbazole (mCPPO1) 3,5-Di(9H-carbazol-9-yl)biphenyl (Ph-mCP), TSPO1, 9-(3 '-biphenyl]-3-yl)-9H-pyrido[2,3-b]indole (CzBPCb), bis(2-methylphenyl)diphenylsilane (UGH-1), 1,4-bis(triphenylsilyl)benzene (UGH- 2), 1,3-bis(triphenylsilyl)benzene (UGH-3), 9,9-spiorobifluoren-2-yl-diphenyl-phosphine oxide (SPPO1), 9,9'-(5-(triphenylsilyl)-1, It may be one of 3-phenylene)bis(9H-carbazole) (SimCP).

For example, the blue dopant is perylene, 4,4'-bis[4-(di-p-tolylamino)styryl]biphenyl (DPAVBi), 4-(di-p-tolylamino)-4-4'-[(di -p-tolylamino)styryl]stilbene (DPAVB), 4,4'-bis[4-(diphenylamino)styryl]biphenyl (BDAVBi), 2,7-bis(4-diphenylamino)styryl)-9,9-spiorfluorene ( spiro-DPVBi), [1,4-bis[2-[4-[N,N-di(p-tolyl)amino]phenyl]vinyl] benzene (DSB), 1-4-di-[4-(N ,N-diphenyl)amino]styryl-benzene (DSA), 2,5,8,11-tetra-tetr-butylperylene (TBPe), bis(2-hydroxylphenyl)-pyridine)beryllium (Bepp2), 9-(9- Phenylcarbazole-3-yl)-10-(naphthalene-1-yl)anthracene (PCAN), mer-tris(1-phenyl-3-methylimidazolin-2-ylidene-C,C(2)'iridium(III) (mer -Ir(pmi)3), 'iridium(III) (fac-Ir(dpbic)3), bis(3,4,5-trifluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium(III ) (Ir(tfpd)2pic), tris(2-(4,6-difluorophenyl)pyridine))iridium(III) (Ir(Fppy)3), bis[2-(4,6-difluorophenyl)pyridinato-C2, It may be one of N](picolinato)iridium(III) (FIrpic).

The first light emitting unit 310 may further include a first electron transport layer 316 located on the first light emitting material layer 312. Additionally, the first light emitting unit 310 may further include a hole injection layer 314 located below the first hole transport layer 320.

For example, the first light emitting unit 310 includes a hole injection layer 314, a first hole transport layer 320, a first light emitting material layer 312, and a first electron layer sequentially stacked on the first electrode 210. It may include a transport layer 316, and the high refractive index layer 322 may be located between the hole injection layer 314 and the low refractive index layer 326.

In the second light emitting unit 330, the green light emitting material layer 332b may be located between the red light emitting material layer 332a and the second electrode 230.

The red light-emitting material layer 332a may include a red host and a red dopant. The red host may include a p-type host and an n-type host, and the red dopant may include one of a fluorescent compound, a phosphorescent compound, and a delayed fluorescent compound. In one embodiment, the red dopant can be a phosphorescent compound.

For example, red hosts include mCP-CN, CBP, mCBP, mCP, DPEPO, 2,8-bis(diphenylphosphoryl)dibenzothiophene (PPT), 1, 3,5-Tri[(3-pyridyl)-phen-3-yl]benzene (1,3,5-Tri[(3-pyridyl)-phen-3-yl]benzene; TmPyPB), 2,6- Di(9H-carbazol-9-yl)pyridine (2,6-Di(9H-carbazol-9-yl)pyridine; PYD-2Cz), 2,8-di(9H-carbazol-9-yl)di Benzothiophene (2,8-di(9H-carbazol-9-yl)dibenzothiophene; DCzDBT), 3', 5'-di(carbazol-9-yl)-[1,1'-biphenyl]-3 ,5-dicarbonitrile (3',5'-Di(carbazol-9-yl)-[1,1'-bipheyl]-3,5-dicarbonitrile; DCzTPA), 4'-(9H-carbazol-9 -yl) biphenyl-3,5-dicarbonitrile (4'-(9H-carbazol-9-yl)biphenyl-3,5-dicarbonitrile (4'-(9H-carbazol-9-yl)biphenyl-3, 5-dicarbonitrile; pCzB-2CN), 3'-(9H-carbazol-9-yl)biphenyl-3,5-dicarbonitrile (3'-(9H-carbazol-9-yl)biphenyl-3,5 -dicarbonitrile; mCzB-2CN), TSPO1, 9-(9-phenyl-9H-carbazol-6-yl)-9H-carbazole (9-(9-phenyl-9H-carbazol-6-yl)-9H- carbazole; CCP), 4-(3-(triphenylen-2-yl)phenyl)dibenzo[b,d]thiophene (4-(3-(triphenylen-2-yl)phenyl)dibenzo[b,d ]thiophene), 9-(4-(9H-carbazol-9-yl)phenyl)-9H-3,9'-bicarbazole (9-(4-(9H-carbazol-9-yl)phenyl)- 9H-3,9'-bicarbazole), 9-(3-(9H-carbazol-9-yl)phenyl)-9H-3,9'-bicarbazole (9-(3-(9H-carbazol-9 -yl)phenyl)-9H-3,9'-bicarbazole), 9-(6-(9H-carbazol-9-yl)pyridin-3-yl)-9H-3,9'-bicarbazole (9 -(6-(9H-carbazol-9-yl)pyridin-3-yl)-9H-3,9'-bicabazole), 9,9'-diphenyl-9H,9'H-3,3'-bi Carbazole (9,9'-Diphenyl-9H,9'H-3,3'-bicarbazole; BCzPh), 1,3,5-Tris(carbazole-9-yl)benzene; TCP), TCTA, 4,4'-bis(carbazole) -9-yl)-2,2'-dimethylbiphenyl (4,4'-Bis(carbazole-9-yl)-2,2'-dimethylbipheyl; CDBP), 2,7-bis(carbazole-9- 1)-9,9-dimethylfluorene (2,7-Bis(carbazole-9-yl)-9,9-dimethylfluorene(DMFL-CBP), 2,2',7,7'-tetrakis(carbazole -9-yl)-9,9-spirofluorene (2,2',7,7'-Tetrakis(carbazole-9-yl)-9,9-spirofluorene; Spiro-CBP), 3,6-bis (carbazole-9-yl)-9-(2-ethyl-hexyl)-9H-carbazole(3,6-Bis(carbazole-9-yl)-9-(2-ethyl-hexyl)-9H-carbazole It may include one or more selected from the group consisting of ; TCz1).

The red dopant is [bis(2-(4,6-dimethyl)phenylquinoline)](2,2,6,6-tetramethylheptane-3,5-dionate)iridium(Ⅲ), bis[2-(4-n- hexylphenyl)quinoline](acetylacetonate)iridium(Ⅲ) (Hex-Ir(phq)2(acac)), tris[2-(4-n-hexylphenyl)quinoline]iridium(Ⅲ) (Hex-Ir(phq)3) , tris[2-phenyl-4-methylquinoline]iridium(Ⅲ) (Ir(Mphq)3), bis(2-phenylquinoline)(2,2,6,6-tetramethylheptene-3,5-dionate)iridium(Ⅲ) (Ir(dpm)PQ2), bis(phenylisoquinoline)(2,2,6,6-tetramethylheptene-3,5-dionate)iridium(Ⅲ) (Ir(dpm)(piq)2), bis[(4-n -hexylphenyl)isoquinoline](acetylacetonate)iridium(Ⅲ) (Hex-Ir(piq)2(acac)), tris[2-(4-n-hexylphenyl)quinoline]iridium(Ⅲ) (Hex-Ir(piq)3 ), tris(2-(3-methylphenyl)-7-methyl-quinolato)iridium (Ir(dmpq)3), bis[2-(2-methylphenyl)-7-methyl-quinoline](acetylacetonate)iridium(Ⅲ) (Ir(dmpq)2(acac)), bis[2-(3,5-dimethylphenyl)-4-methyl-quinoline](acetylacetonate)iridium(Ⅲ) (Ir(mphmq)2(acac)), tris(dibenzoylmethane ) may be selected from the group consisting of mono(1,10-phenanthroline)europium(Ⅲ) (Eu(dbm)3(phen)).

The green light-emitting material layer 332b may include a green host and a green dopant. The green host may include a p-type host and an n-type host, and the green dopant may include one of a fluorescent compound, a phosphorescent compound, and a delayed fluorescent compound. In one embodiment, the green dopant can be a phosphorescent compound.

For example, green hosts include mCP-CN, CBP, mCBP, mCP, DPEPO, 2,8-bis(diphenylphosphoryl)dibenzothiophene (PPT), TmPyPB, PYD-2Cz, 2,8-di(9H-carbazol-9-yl)dibenzothiophene (DCzDBT), 3', 5'-di (carbazol-9-yl)-[1,1'-bipheyl]-3,5-dicarbonitrile (3',5'-Di(carbazol-9-yl)-[1,1'-bipheyl] -3,5-dicarbonitrile; DCzTPA), 4'-(9H-carbazol-9-yl)biphenyl-3,5-dicarbonitrile (4'-(9H-carbazol-9-yl)biphenyl-3, 5-dicarbonitrile(4'-(9H-carbazol-9-yl)biphenyl-3,5-dicarbonitrile; pCzB-2CN), 3'-(9H-carbazol-9-yl)biphenyl-3,5-dicarbonitrile Bonitrile (3'-(9H-carbazol-9-yl)biphenyl-3,5-dicarbonitrile; mCzB-2CN), TSPO1, 9-(9-phenyl-9H-carbazol-6-yl)-9H-carbazol It may include one or more selected from the group consisting of sol (9-(9-phenyl-9H-carbazol-6-yl)-9H-carbazole; CCP).

The green dopant is [bis(2-phenylpyridine)](pyridyl-2-benzofuro[2,3-b]pyridine)iridium ([Bis(2-phenylpyridine)](pyridyl-2-benzofuro[2, 3-b]pyridine)iridium), Tris[2-phenylpyridine]iridium(Ⅲ) (Tris[2-phenylpyridine]iridium(Ⅲ); Ir(ppy)3), Pac-Tris(2-phenylpyridine)iridium( Ⅲ) (fac-Tris(2-phenylpyridine)iridium(Ⅲ); fac-Ir(ppy)3), bis(2-phenylpyridine)(acetylacetonate)iridium(Ⅲ) (Bis(2-phenylpyridine)(acetylacetonate) )iridium(Ⅲ); Ir(ppy)2(acac)), Tris[2-(p-tolyl)pyridine]iridium(Ⅲ); Ir( mppy)3), Bis(2-(naphthalene-2-yl)pyridine)(acetylacetonate)iridium(Ⅲ) (Bis(2-(naphthalene-2-yl)pyridine)(acetylacetonate)iridium(Ⅲ); Ir( npy)2acac), Tris(2-phenyl-3-methyl-pyridine)iidium; Ir(3mppy)3), Pac-Tris(2-(3-p) -Xylyl)phenyl)pyridine iridium(Ⅲ) (fac-Tris(2-(3-p-xylyl)phenyl)pyridine iridium(Ⅲ); TEG).

The second light-emitting material layer 330 may further include a yellow-green light-emitting material layer located between the red light-emitting material layer 332a and the green light-emitting material layer 332b.

The yellow-green light-emitting material layer may include a yellow-green host and a yellow-green dopant. The yellow-green host may include a p-type host and an n-type host, and the yellow-green dopant may include one of a fluorescent compound, a phosphorescent compound, and a delayed fluorescent compound. In one embodiment, the yellow-green dopant may be a phosphorescent compound.

The yellow-green host may be the same as the green host described above.

The yellow-green dopant is 5,6,11,12-Tetraphenylnaphthalene (5,6,11,12-Tetraphenylnaphthalene; Rubrene), 2,8-di-tert-butyl-5,11-bis(4-tert-butylphenyl) )-6,12-diphenyltetracene (2,8-Di-tert-butyl-5,11-bis(4-tert-butylphenyl)-6,12-diphenyltetracene; TBRb), bis(2-phenylbenzothia Zolato)(acetylacetonate)irdium(Ⅲ)(Bis(2-phenylbenzothiazolato)(acetylacetonate)irdium(Ⅲ); Ir(BT)2(acac)), bis(2-(9,9-diethyl-flu) oren-2-yl)-1-phenyl-1H-benzo[d]imidazolato)(acetylacetonate)iridium(Ⅲ)(Bis(2-(9,9-diethytl-fluoren-2-yl)- 1-phenyl-1H-benzo[d]imdiazolato)(acetylacetonate)iridium(Ⅲ)), bis(2-phenylpyridine)(3-(pyridin-2-yl)-2H- Chromen-2-onate)iridium(Ⅲ) (Bis(2-phenylpyridine)(3-(pyridine-2-yl)-2H-chromen-2-onate)iridium(Ⅲ); fac-Ir(ppy)2Pc ), Bis(2-(2,4-difluorophenyl)quinoline)(picolinate)iridium(Ⅲ); FPQIrpic ), Bis(4-phenylthieno[3,2-c]pyridinato-N,C2'(acetylacetonate)iridium(Ⅲ) (Bis(4-phenylthieno[3,2-c]pyridinato-N, C2') (acetylacetonate) iridium (Ⅲ) PO-01);

The second light emitting unit 330 may further include a second hole transport layer 334 located below the second light emitting material layer 332. In addition, the second light emitting unit 330 includes at least one of a second electron transport layer 336 located on the second light emitting material layer 332 and an electron injection layer 338 located on the second electron transport layer 336. It may further include.

For example, the second light emitting unit 330 includes a second hole transport layer 334, a second light emitting material layer 332, a second electron transport layer 336, and an electron injection layer sequentially stacked on the charge generation layer 360. It may include layer 338.

The hole injection layer 314 is 4,4',4"-tris(3-methylphenylamino)triphenylamine (MTDATA), 4,4', 4"-tris(N,N-diphenyl-amino)triphenylamine (4,4',4"-tris(N,N-diphenyl-amino)triphenylamine; NATA), 4,4',4"-tris (N-(naphthalene-1-yl)-N-phenyl-amino)triphenylamine (4,4',4"-tris(N-(naphthalene-1-yl)-N-phenyl-amino)triphenylamine; 1T -NATA), 4,4',4"-tris(N-(naphthalene-2-yl)-N-phenyl-amino)triphenylamine (4,4',4"-tris(N-(naphthalene-2 -yl)-N-phenyl-amino)triphenylamine; 2T-NATA), copper phthalocyanine (CuPc), tris(4-carbazoyl-9-yl- phenyl)amine; TCTA), N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4"-diamine(N,N'-diphenyl- N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4"-diamine; NPB or NPD), 1,4,5,8,9,11-hexaazatriphenylenehexacarbo Nitrile (1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile; HAT-CN), 1,3,5-tris[4-(diphenylamino)phenyl]benzene (1,3,5-tris[4- (diphenylamino)phenyl]benzene; TDAPB), poly(3,4-ethylenedioxythiophene)polystyrene sulfonate (PEDOT/PSS), N-(biphenyl-4-yl )-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine(N-(biphenyl-4-yl)-9 ,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine), N,N'-diphenyl-N,N'-di- [4-(N,N-diphenyl-amino)phenyl]benzidine (N,N'-diphenyl-N,N'-di[4-(N,N-diphenyl-amino)phenyl]benzidine; NPNPB) may include a hole injection material, but is not limited thereto. The hole injection layer 314 may have a thickness of 10 to 100 Å. For example, the hole -injected layer 314 can have a thickness of 20 å, 25 m, 30 m, 35 må, 40 m, 45 må, 50å, 55 m, 60 mm, 65å, 70 å, 75å, 80 å, 85å, 90 å, 95å, there is.

The second hole transport layer 334 of the second light emitting unit 330 has a single-layer structure. That is, the first hole transport layer 320 located between the first light-emitting material layer 312, which is a blue light-emitting material layer, and the first electrode 210 has a double-layer structure of the high refractive index layer 322 and the low refractive index layer 326. On the other hand, the second hole transport layer 334 located between the charge generation layer 360 and the second light emitting material layer 332 including the red light emitting material layer 332a and the green light emitting material layer 332b is a single layer. It has a structure.

The second hole transport layer 334 is N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (N,N'-diphenyl) -N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine), NPB(NPD), 4,4'-bis(N-carbazolyl)-1, 1'-biphenyl (4,4'-bis(N-carbazolyl)-1,1'-biphenyl; CBP), poly[N,N'-bis(4-butylphenyl)-N,N'-bis( phenyl)-benzidine](poly[N,N'-bis(4-butylpnehyl)-N,N'-bis(phenyl)-benzidine]; Poly-TPD), poly[(9,9-dionylfluorenyl) -2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))](poly[(9,9-dioctylfluorenyl-2,7-diyl)- co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))], TFB), di-[4-(N,N-di-p-tolyl-amino)phenyl]cyclohexane (di -[4-(N,N-di-p-tolyl-amino)-phenyl]cyclohexane), 3,5-di(9H-carbazol-9-yl)-N,N-diphenylaniline (3 ,5-di(9H-carbazol-9-yl)-N,N-diphenylaniline), N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl- 9H-carbazol-3-yl) phenyl)-9H-fluoren-2-amine (N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol -3-yl)phenyl)-9H-fluoren-2-amine), N-(biphenyl]-4-yl)-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl) Biphenyl)-4-amine (N-(biphenyl-4-yl)-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)biphenyl-4-amine), N-([1 ,1'-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine ( N-([1,1'-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2- amine) may contain a hole transport material. In one embodiment, the second hole transport layer 334 may include a compound of Chemical Formula 6.

The second hole transport layer 334 may have a thickness of 50 to 200 Å, preferably 50 to 100 Å or 100 to 150 Å. The thickness of the second hole transport layer 334 may be smaller than the thickness of the first hole transport layer 320. For example, the second hole transport layer 334 may have a thickness of 50Å, 75Å, 100Å, 125Å, 150Å, 175Å, or 200Å.

In one embodiment, the refractive index of the hole transport material forming the second hole transport layer 334 is smaller than the refractive index of the first hole transport material 324 forming the high refractive index layer 322, and the second hole forming the low refractive index layer 326 is smaller than the refractive index of the hole transport material forming the second hole transport layer 334. It may be greater than the refractive index of the transport material 328.

Each of the first and second electron transport layers 316 and 336 is made of tris-(8-hydroxyquinoline aluminum; Alq3), 2-biphenyl-4-yl-5-(4- Tertiary-butylphenyl)-1,3,4-oxadiazole (2-biphenyl-4-yl-5-(4-t-butylphenyl)-1,3,4-oxadiazole; PBD), Spiro-PBD , lithium quinolate (Liq), 1,3,5-Tris(N-phenylbenzimidazol-2-yl)benzene; TPBi), bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-biphenyl-4-olato)aluminum (Bis(2-methyl-8-quinolinolato-N1,O8 )-(1,1'-biphenyl-4-olato)aluminum; BAlq), 4,7-diphenyl-1,10-phenanthroline (Bphen), 2 ,9-Bis(naphthalene-2-yl)4,7-diphenyl-1,10-phenanthroline (2,9-Bis(naphthalene-2-yl)4,7-diphenyl-1,10-phenanthroline; NBphen), 2,9-dimethyl-4,7-diphenyl-1,10-phenathroline (2,9-Dimethyl-4,7-diphenyl-1,10-phenathroline; BCP), 3-(4- Biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (3-(4-Biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole; TAZ), 4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (4-(Naphthalen-1-yl)-3,5-diphenyl-4H-1 ,2,4-triazole; NTAZ), 1,3,5-Tri(p-pyrid-3-yl-phenyl)benzene TpPyPB), 2,4,6-tris (3'-(pyridin-3-yl)biphenyl-3-yl)1,3,5-triazine (2,4,6-Tris(3'-( pyridin-3-yl)biphenyl-3-yl)1,3,5-triazine; TmPPPyTz), poly[(9,9-bis(3'-((N,N-dimethyl)-N-ethylammonium)-propyl)-2,7-fluorene)-alt-2,7-(9, 9-dioctylfluorene)](Poly[9,9-bis(3'-((N,N-dimethyl)-N-ethylammonium)-propyl)-2,7-fluorene]-alt-2,7- (9,9-dioctylfluorene)]; PFNBr), tris(phenylquinoxaline; TPQ), diphenyl-4-triphenylsilyl-phenylphosphine oxide; TSPO1 ), 2-[4-(9,10-di-naphthalen-2-yl-anthracen-2-yl)phenyl)]-1-phenyl-1H-benzimidazole (2-[4-(9,10- It may contain an electron transport material such as Di-2-naphthalen2-yl-2-anthracen-2-yl)phenyl]-1-phenyl-1H-benzimidazole; Each of the first and second electron transport layers 316 and 336 may have a thickness of 100 to 500 Å, preferably 100 to 300 Å or 200 to 300 Å. For example, the first and second electron transport layers 316 and 336 each have a thickness of 150 Å, 175 Å, 200 Å, 225 Å, 250 Å, 275 Å, 300 Å, 350 Å, 375 Å, 400 Å, 425 Å, 450 Å, 475 Å, or 500 Å. have a thickness of Å You can.

, 바람직하게는 1 내지 10

또는 5 내지 20Å의 두께를 가질 수 있다. 예를 들어, 전자주입층(338)은 1Å, 5Å, 10Å, 15Å, 20Å, 25Å, 또는 30Å의 두께를 가질 수 있다.The electron injection layer 338 may include an electron injection material that is one of LiF, CsF, NaF, BaF ₂ , Liq (lithium quinolate), lithium benzoate, and sodium stearate. The electron injection layer 338 is 1 to 30

, preferably 1 to 10

Alternatively, it may have a thickness of 5 to 20 Å. For example, the electron injection layer 338 may have a thickness of 1Å, 5Å, 10Å, 15Å, 20Å, 25Å, or 30Å.

The charge generation layer 360 is located between the first light emitting part 310 and the second light emitting part 330. That is, the first light emitting unit 310 and the second light emitting unit 330 are connected by the charge generation layer 360. The charge generation layer 360 may be a PN junction charge generation layer in which an N-type charge generation layer 362 and a P-type charge generation layer 364 are bonded.

The N-type charge generation layer 362 is located between the first electron transport layer 316 and the second hole transport layer 334, and the P-type charge generation layer 364 is located between the N-type charge generation layer 362 and the second hole transport layer. It is located between (334).

The N-type charge generation layer 362 may be an organic layer doped with an alkali metal such as Li, Na, K, or Cs and/or an alkaline earth metal such as Mg, Sr, Ba, or Ra. For example, the N-type charge generation layer 392 is a host that is an organic material such as 4,7-dipheny-1,10-phenanthroline (Bphen) or MTDATA. It is made of an N-type charge generating material containing a dopant that is an alkali metal or alkaline earth metal, and the dopant may be doped at 0.01 to 30% by weight.

The P-type charge generation layer 364 is an inorganic material selected from the group consisting of tungsten oxide (WOx), molybdenum oxide (MoOx), beryllium oxide (Be ₂ O ₃ ), vanadium oxide (V ₂ O ₅ ), and combinations thereof. , NPD, HAT-CN, F4TCNQ, TPD, TNB, TCTA, N,N'-dioctyl-3,4,9,10-perylenedicarboximide (N,N'-dioctyl-3,4,9, It may be made of a P-type charge generating material containing an organic material selected from the group consisting of 10-perylenedicarboximide; PTCDI-C8) and combinations thereof.

As described above, the organic light-emitting diode (D1) of the present invention includes a first light-emitting portion 310 including a first light-emitting material layer 312, which is a blue light-emitting material layer, and a first hole transport layer 320, and a red light-emitting layer. It includes a material layer 332a, a green light-emitting material layer 332b, and a second light-emitting part 330 located between the first light-emitting part 310 and the second electrode 230, and a first hole transport layer ( 320) includes a high refractive index layer 322 and a low refractive index layer 326. Therefore, in the organic light emitting diode (D1) of the present invention, blue light emission efficiency is improved and color viewing angle is improved.

Figure 4 is a schematic cross-sectional view of an organic light-emitting diode according to a third embodiment of the present invention.

As shown in FIG. 4, the organic light emitting diode D2 includes a first electrode 210, a second electrode 230 facing the first electrode 210, the first electrode 210, and the second electrode ( 230), which includes an organic light-emitting layer 220 located between the organic light-emitting layer 220, a first hole transport layer 420 including a high refractive index layer 422 and a low refractive index layer 426, and a first hole transport layer 420 that is a blue light-emitting material layer. 1. It includes a first light emitting part 410 including a light emitting material layer 412, a second light emitting material layer 432 including a red light emitting material layer 432a and a green light emitting material layer 432b, and a first light emitting material layer 432. It includes a second light emitting part 430 located between the light emitting part 410 and the second electrode 230, and a third light emitting material layer 442, which is a blue light emitting material layer, and the second light emitting part 430 and the third light emitting material layer 442 are It includes a third light emitting unit 440 located between the two electrodes 230.

The organic light-emitting layer 220 is a first charge generation layer 460 located between the first light-emitting part 410 and the second light-emitting part 430, and between the second light-emitting part 430 and the third light-emitting part 440. It may further include a second charge generation layer 470 located in .

The organic light-emitting display device (100) includes a red pixel area (RP), a green pixel area (GP), and a blue pixel area (BP), and an organic light-emitting diode (D2) is positioned in each of the red pixel area (RP), the green pixel area (GP), and the blue pixel area (BP) and emits white light.

In the first light emitting unit 410, the first hole transport layer 420 has a double-layer structure of the high refractive index layer 422 and the low refractive index layer 426, and the low refractive index layer 426 has the high refractive index layer 422 and the first It is located between the light emitting material layers 412. The low refractive index layer 426 may be in contact with the high refractive index layer 422 and the first light emitting material layer 412.

The high refractive index layer 422 includes a first hole transport material 424 having a first refractive index, and the low refractive index layer 426 includes a second hole transport material 428 having a second refractive index less than the first refractive index. do. The difference between the first refractive index and the second refractive index may be 0.05 or more. In one embodiment, the difference between the first and second refractive indices may be 0.05 or more, 0.25 or less, preferably 0.09 or more, 0.25 or less, more preferably 0.1 or more, 0.25 or less, more preferably 0.15 or more, 0.25 or less. there is. For example, the first refractive index may range from 1.9 to 2.1, and the second refractive index may range from 1.7 to 1.9.

In one embodiment, the first hole transport material 424 may include at least one of a compound of Formula 1 and a compound of Formula 2, and the second hole transport material 428 may include a compound of Formula 2, a compound of Formula 3, It may include at least one of the compounds of Formula 4 and Formula 5.

In one embodiment of the present invention, the first hole transport material 424 may be a compound of Formula 1. That is, the high refractive index layer 422 may be made only of the compound of Chemical Formula 1.

In one embodiment of the present invention, the first hole transport material 424 may include a compound of Formula 1 and a compound of Formula 2. In this case, the weight ratio of the compound of Formula 1 may be equal to or greater than the weight ratio of the compound of Formula 2. For example, the weight ratio of the compound of Formula 1 and the compound of Formula 2 may be 5:5 to 9:1, preferably 6:4, 7:3, or 8:2.

In one embodiment of the present invention, the second hole transport material 428 may include only the compound of Formula 3. That is, the low refractive index layer 426 may be made only of the compound of Chemical Formula 3.

In one embodiment of the present invention, the second hole transport material 428 may include only the compound of Formula 4. That is, the low refractive index layer 426 may be made only of the compound of Chemical Formula 4.

In one embodiment of the present invention, the second hole transport material 428 may include only the compound of Formula 5. That is, the low refractive index layer 426 may be made only of the compound of Chemical Formula 5.

In one embodiment of the present invention, the second hole transport material 428 may include at least two of the Formula 2 compound, the Formula 3 compound, the Formula 4 compound, and the Formula 5 compound.

In one embodiment of the present invention, the second hole transport material 428 may include a compound of Formula 2 and a compound of Formula 4. In this case, the weight ratio of the compound of Formula 2 and the weight ratio of the compound of Formula 4 may be the same or different. For example, the low refractive index layer 426 can be formed by co-depositing a compound of Chemical Formula 2 and a compound of Chemical Formula 4.

In one embodiment of the present invention, the second hole transport material 428 may include a compound of Chemical Formula 4 and a compound of Chemical Formula 5. In this case, the weight ratio of the compound of Formula 4 and the weight ratio of the compound of Formula 5 may be the same or different.

In one embodiment of the present invention, the second hole transport material 428 may include a compound of Formula 2 and a compound of Formula 5. In this case, the weight ratio of the compound of Formula 2 and the weight ratio of the compound of Formula 5 may be the same or different.

In one embodiment of the present invention, the first hole transport material 424 may include at least one of a compound of Formula 1 and a compound of Formula 2, and the second hole transport material 428 may include a compound of Formula 3, a compound of Formula 4, It may include at least one of the compounds of Formula 5.

The high refractive index layer 422 may have a first thickness t1, and the low refractive index layer 426 may have a second thickness t2 greater than the first thickness t1. The first thickness (t1) of the high refractive index layer 422 may be 10 to 49% of the thickness of the first hole transport layer 420, and the second thickness (t2) of the low refractive index layer 426 may be 10 to 49% of the thickness of the first hole transport layer 420. ) may be 51 to 90% of the thickness. In one embodiment, the first thickness t1 of the high refractive index layer 422 may be 20 to 45%, preferably 30 to 45%, of the thickness of the first hole transport layer 420.

For example, the first thickness (t1) may be in the range of 200 to 500 Å, preferably 300 to 450 Å, and the second thickness (t2) may be in the range of 500 to 800 Å, preferably 550 to 700 Å. For example, the first thickness (t1) may be in the range of 200 to 500 Å, preferably 250 to 450 Å, 300 to 450 Å, 250 to 400 Å, or 300 to 400 Å, and the second thickness (t2) may be in the range of 500 to 800 Å. , preferably in the range of 500 to 750 Å, 550 to 750 Å, or 550 to 700 Å.

The first light emitting material layer 412 is a blue light emitting material layer and may include a first blue host and a first blue dopant. The first blue dopant may include at least one of a fluorescent compound, a phosphorescent compound, and a delayed fluorescent compound. In one embodiment, the first blue dopant may be a fluorescent compound.

For example, the first blue host may be the blue host material described above, and the first blue dopant may be the blue dopant material described above.

The first light emitting unit 410 may further include a first electron transport layer 416 located on the first light emitting material layer 412. Additionally, the first light emitting unit 410 may further include a hole injection layer 414 located below the first hole transport layer 420.

For example, the first light emitting unit 410 includes a hole injection layer 414, a first hole transport layer 420, a first light emitting material layer 412, and a first electron layer sequentially stacked on the first electrode 210. It may include a transport layer 416, and the high refractive index layer 422 may be located between the hole injection layer 414 and the low refractive index layer 426.

In the second light emitting unit 430, the green light emitting material layer 432b may be located between the red light emitting material layer 432a and the second electrode 230.

The red light-emitting material layer 432a may include a red host and a red dopant. The red host may include a p-type host and an n-type host, and the red dopant may include one of a fluorescent compound, a phosphorescent compound, and a delayed fluorescent compound. In one embodiment, the red dopant can be a phosphorescent compound.

For example, the red host may be the red host material described above, and the red dopant may be the red dopant material described above.

The green light-emitting material layer 432b may include a green host and a green dopant. The green host may include a p-type host and an n-type host, and the green dopant may include one of a fluorescent compound, a phosphorescent compound, and a delayed fluorescent compound. In one embodiment, the green dopant can be a phosphorescent compound.

For example, the green host may be the green host material described above, and the green dopant may be the green dopant material described above.

The second light-emitting material layer 430 may further include a yellow-green light-emitting material layer located between the red light-emitting material layer 432a and the green light-emitting material layer 432b.

The yellow-green light-emitting material layer may include a yellow-green host and a yellow-green dopant. The yellow-green host may include a p-type host and an n-type host, and the yellow-green dopant may include one of a fluorescent compound, a phosphorescent compound, and a delayed fluorescent compound. In one embodiment, the yellow-green dopant may be a phosphorescent compound.

For example, the yellow-green host may be the yellow-green host material described above, and the yellow-green dopant may be the yellow-green dopant material described above.

The second light emitting unit 430 may further include a second hole transport layer 434 located below the second light emitting material layer 432. Additionally, the second light emitting unit 430 may further include a second electron transport layer 436 located on the second light emitting material layer 432.

For example, the second light emitting unit 430 includes a second hole transport layer 434, a second light emitting material layer 432, and a second electron transport layer 436 sequentially stacked on the first charge generation layer 460. It can be included.

The third light emitting material layer 442 is a blue light emitting material layer and may include a second blue host and a second blue dopant. The second blue dopant may include at least one of a fluorescent compound, a phosphorescent compound, and a delayed fluorescent compound. In one embodiment, the second blue dopant may be a fluorescent compound.

For example, the second blue host may be the blue host material described above, and the second blue dopant may be the blue dopant material described above.

The third light emitting unit 440 may further include a third hole transport layer 444 located below the third light emitting material layer 442. In addition, the third light emitting unit 440 includes at least one of the third electron transport layer 446 located on the third light emitting material layer 442 and the electron injection layer 448 located on the third electron transport layer 446. You can include one more.

For example, the third light emitting unit 440 includes a third hole transport layer 444, a third light emitting material layer 442, a third electron transport layer 446, which are sequentially stacked on the second charge generation layer 470. It may include an electron injection layer 448.

The hole injection layer 414 may include the hole injection material described above and may have a thickness of 10 to 100 Å. For example, the hole -shaped restraint layer 414 can have a thickness of 20 å, 25 m, 30 m, 35 må, 40 m, 45 mP, 55 å, 60 å, 65å, 70 å, 75å, 80 å, 85 å, 90 å, 95å, there is.

The second hole transport layer 434 of the second light emitting unit 430 and the third hole transport layer 444 of the third light emitting unit 440 each have a single-layer structure. That is, the first hole transport layer 420 located between the first light-emitting material layer 412, which is a blue light-emitting material layer, and the first electrode 210 has a double-layer structure of the high refractive index layer 422 and the low refractive index layer 426. On the other hand, a second hole transport layer 434 located between the first charge generation layer 460 and the second light emitting material layer 432 including the red light emitting material layer 432a and the green light emitting material layer 432b, and Each of the third hole transport layers 444 located between the third light-emitting material layer 442, which is a blue light-emitting material layer, and the second charge generation layer 470 has a single-layer structure.

Each of the second hole transport layer 434 and the third hole transport layer 444 may include the hole transport material described above. In one embodiment, each of the second hole transport layer 434 and the third hole transport layer 444 may include a compound of Formula 6.

In one embodiment, the refractive index of the hole transport material forming the second hole transport layer 434 and the refractive index of the hole transport material forming the third hole transport layer 444 are each of the first hole transport material 424 forming the high refractive index layer 422. ) and may be larger than the refractive index of the second hole transport material 428 forming the low refractive index layer 426.

The thickness of the second hole transport layer 434 and the third hole transport layer 444 may each be smaller than the thickness of the first hole transport layer 420. For example, the second hole transport layer 434 may have a thickness of 50 to 200 Å, preferably 50 to 100 Å, and the third hole transport layer 444 may have a thickness of 700 to 800 Å. For example, the second hole transport layer 434 may have a thickness of 50Å, 75Å, 100Å, 125Å, 150Å, 175Å, or 200Å, and the third hole transport layer 444 may have a thickness of 700Å, 725Å, 750Å, 775Å, or It can have a thickness of 800Å.

Each of the first to third electron transport layers 416, 436, and 446 may include the electron transport material described above. Each of the first to third electron transport layers 416, 436, and 446 may have a thickness of 100 to 500 Å, preferably 100 to 300 Å. For example, the first to third electron transport layers 416, 436, and 446 each have 150Å, 175Å, 200Å, 225Å, 250Å, 275Å, 300Å, 350Å, 375Å, 400Å, 425Å, 450Å, or 500Å thick You can have

, 바람직하게는 1 내지 10

의 두께를 가질 수 있다. 예를 들어, 전자주입층(448)은 1Å, 5Å, 10Å, 15Å, 20Å, 25Å, 또는 30Å의 두께를 가질 수 있다.The electron injection layer 448 may include an electron injection material that is one of LiF, CsF, NaF, BaF ₂ , Liq (lithium quinolate), lithium benzoate, and sodium stearate. The electron injection layer 448 is 1 to 30

, preferably 1 to 10

It can have a thickness of For example, the electron injection layer 448 may have a thickness of 1Å, 5Å, 10Å, 15Å, 20Å, 25Å, or 30Å.

The first charge generation layer 460 is located between the first light emitting part 410 and the second light emitting part 430. That is, the first light emitting unit 410 and the second light emitting unit 430 are connected by the first charge generation layer 460. The first charge generation layer 460 may be a PN junction charge generation layer in which the first N-type charge generation layer 462 and the first P-type charge generation layer 464 are bonded.

The first N-type charge generation layer 462 is located between the first electron transport layer 416 and the second hole transport layer 434, and the first P-type charge generation layer 464 is located between the first N-type charge generation layer 462. ) and the second hole transport layer 434.

The first N-type charge generation layer 462 may be made of the above-described N-type charge generation material, and the first P-type charge generation layer 464 may be made of the above-described P-type charge generation material.

The second charge generation layer 470 is located between the second light emitting part 430 and the third light emitting part 440. That is, the second light emitting unit 430 and the third light emitting unit 440 are connected by the second charge generation layer 470. The second charge generation layer 470 may be a PN junction charge generation layer in which a second N-type charge generation layer 472 and a second P-type charge generation layer 474 are bonded.

The second N-type charge generation layer 472 is located between the second electron transport layer 436 and the third hole transport layer 444, and the second P-type charge generation layer 474 is located between the second N-type charge generation layer 472. ) and the third hole transport layer 444.

The second N-type charge generation layer 472 may be made of the above-described N-type charge generation material, and the second P-type charge generation layer 474 may be made of the above-described P-type charge generation material.

As described above, the organic light emitting diode (D2) of the present invention includes a first light emitting material layer 412 that is a blue light emitting material layer, a first light emitting portion 410 including a first hole transport layer 420, and a red light emitting material layer. A second light-emitting part 430 that includes a material layer 432a and a green light-emitting material layer 432b and is located between the first light-emitting part 410 and the second electrode 230, and a third light-emitting material layer that is blue. It includes a light emitting material layer 442 and a third light emitting part 440 located between the second light emitting part 430 and the second electrode 230, and the first hole transport layer 420 is a high refractive index layer 422. ) and a low refractive index layer 426. Therefore, in the organic light emitting diode (D2) of the present invention, blue light emission efficiency is improved and color viewing angle is improved.

Figure 5 is a schematic cross-sectional view of an organic light-emitting diode according to a fourth embodiment of the present invention.

As shown in FIG. 5, the organic light emitting diode D3 includes a first electrode 210, a second electrode 230 facing the first electrode 210, the first electrode 210, and the second electrode ( 230), which includes an organic light-emitting layer 220 located between the organic light-emitting layer 220, a first hole transport layer 520 including a high refractive index layer 522 and a low refractive index layer 526, and a first hole transport layer 520 that is a blue light-emitting material layer. 1. A first light emitting unit 510 including a light emitting material layer 512 and a second light emitting material layer 532, which is a green light emitting material layer, between the first light emitting unit 510 and the second electrode 230. A third light emitting unit includes a second light emitting unit 530 located in and a third light emitting material layer 542, which is a blue light emitting material layer, and is located between the second light emitting unit 530 and the second electrode 230. It includes 540 and a fourth light emitting material layer 552, which is a red light emitting material layer, and a fourth light emitting portion 550 located between the first light emitting portion 510 and the first electrode 210.

The organic light-emitting layer 220 includes a first charge generation layer 560, a second light-emitting part 530, and a third light-emitting part 540 located between the first light-emitting part 510 and the second light-emitting part 530. It may further include a second charge generation layer 570 positioned between them and a third charge generation layer 580 positioned between the first and fourth light emitting parts 510 and 550.

The organic light emitting display device 100 includes a red pixel area (RP), a green pixel area (GP), and a blue pixel area (BP), and the organic light emitting diode D3 includes a red pixel area (RP) and a green pixel area ( It is located in each of the blue pixel area (GP) and blue pixel area (BP) and emits white light.

In the first light emitting unit 510, the first hole transport layer 520 has a double-layer structure of a high refractive index layer 522 and a low refractive index layer 526, and the low refractive index layer 526 has a high refractive index layer 522 and the first It is located between the light emitting material layers 512. The low refractive index layer 526 may contact the high refractive index layer 522 and the first light emitting material layer 512.

The high refractive index layer 522 includes a first hole transport material 524 having a first refractive index, and the low refractive index layer 526 includes a second hole transport material 528 having a second refractive index less than the first refractive index. do. The difference between the first refractive index and the second refractive index may be 0.05 or more. In one embodiment, the difference between the first and second refractive indices may be 0.05 or more, 0.25 or less, preferably 0.09 or more, 0.25 or less, more preferably 0.1 or more, 0.25 or less, more preferably 0.15 or more, 0.25 or less. there is. For example, the first refractive index may range from 1.9 to 2.1, and the second refractive index may range from 1.7 to 1.9.

In one embodiment, the first hole transport material 524 may include at least one of a compound of Formula 1 and a compound of Formula 2, and the second hole transport material 528 may include a compound of Formula 2, a compound of Formula 3, It may include at least one of the compounds of Formula 4 and Formula 5.

In one embodiment of the present invention, the first hole transport material 524 may be a compound of Formula 1. That is, the high refractive index layer 522 may be made only of the compound of Chemical Formula 1.

In one embodiment of the present invention, the first hole transport material 524 may include a compound of Formula 1 and a compound of Formula 2. In this case, the weight ratio of the compound of Formula 1 may be equal to or greater than the weight ratio of the compound of Formula 2. For example, the weight ratio of the compound of Formula 1 and the compound of Formula 2 may be 5:5 to 9:1, preferably 6:4, 7:3, or 8:2.

In one embodiment of the present invention, the second hole transport material 528 may include only the compound of Formula 3. That is, the low refractive index layer 526 may be made only of the compound of Chemical Formula 3.

In one embodiment of the present invention, the second hole transport material 528 may include only the compound of Formula 4. That is, the low refractive index layer 526 may be formed only of the compound of Chemical Formula 4.

In one embodiment of the present invention, the second hole transport material 528 may include only the compound of Formula 5. That is, the low refractive index layer 526 may be made only of the compound of Chemical Formula 5.

In one embodiment of the present invention, the second hole transport material 528 may include at least two of the Formula 2 compound, the Formula 3 compound, the Formula 4 compound, and the Formula 5 compound.

In one embodiment of the present invention, the second hole transport material 528 may include a compound of Formula 2 and a compound of Formula 4. In this case, the weight ratio of the compound of Formula 2 and the weight ratio of the compound of Formula 4 may be the same or different. For example, the low refractive index layer 526 can be formed by co-depositing a compound of Formula 2 and a compound of Formula 4.

In one embodiment of the present invention, the second hole transport material (528) may include a compound of chemical formula 4 and a compound of chemical formula 5. In this case, the weight ratio of the compound of chemical formula 4 and the weight ratio of the compound of chemical formula 5 may be the same or different.

In one embodiment of the present invention, the second hole transport material 528 may include a compound of Formula 2 and a compound of Formula 5. In this case, the weight ratio of the compound of Formula 2 and the weight ratio of the compound of Formula 5 may be the same or different.

In one embodiment of the present invention, the first hole transport material 524 may include at least one of a compound of Formula 1 and a compound of Formula 2, and the second hole transport material 528 may include a compound of Formula 3, a compound of Formula 4, It may include at least one of the compounds of Formula 5.

The high refractive index layer 522 may have a first thickness t1, and the low refractive index layer 526 may have a second thickness t2 greater than the first thickness t1. The first thickness (t1) of the high refractive index layer 522 may be 10 to 49% of the thickness of the first hole transport layer (520), and the second thickness (t2) of the low refractive index layer (526) may be 10 to 49% of the thickness of the first hole transport layer (520). ) may be 51 to 90% of the thickness. In one embodiment, the first thickness t1 of the high refractive index layer 522 may be 20 to 45%, preferably 30 to 45%, of the thickness of the first hole transport layer 520.

For example, the first thickness (t1) may be in the range of 200 to 500 Å, preferably 300 to 450 Å, and the second thickness (t2) may be in the range of 500 to 800 Å, preferably 550 to 700 Å. For example, the first thickness (t1) may be in the range of 200 to 500 Å, preferably 250 to 450 Å, 300 to 450 Å, 250 to 400 Å, or 300 to 400 Å, and the second thickness (t2) may be in the range of 500 to 800 Å. , preferably in the range of 500 to 750 Å, 550 to 750 Å, or 550 to 700 Å.

The first light emitting material layer 512 is a blue light emitting material layer and may include a first blue host and a first blue dopant. The first blue dopant may include at least one of a fluorescent compound, a phosphorescent compound, and a delayed fluorescent compound. In one embodiment, the first blue dopant may be a fluorescent compound.

For example, the first blue host may be the blue host material described above, and the first blue dopant may be the blue dopant material described above.

The first light emitting unit 510 may further include a first electron transport layer 516 located on the first light emitting material layer 512.

For example, the first light emitting unit 510 may include a first hole transport layer 520, a first light emitting material layer 512, and a first electron transport layer 516 sequentially stacked on the first electrode 210. The high refractive index layer 522 is between the first electrode 210 and the low refractive index layer 526, between the hole injection layer 556 and the low refractive index layer 526, and between the fourth light emitting unit 540 and the low refractive index layer. It may be located between (526) or between the third charge generation layer (580) and the low refractive index layer (526).

In the second light emitting unit 530, the green light emitting material layer 532 may include a green host and a green dopant. The green host may include a p-type host and an n-type host, and the green dopant may include one of a fluorescent compound, a phosphorescent compound, and a delayed fluorescent compound. In one embodiment, the green dopant can be a phosphorescent compound.

For example, the green host may be the green host material described above, and the green dopant may be the green dopant material described above.

The second light emitting unit 530 may further include a second hole transport layer 534 located below the second light emitting material layer 532. Additionally, the second light emitting unit 530 may further include a second electron transport layer 536 located on the second light emitting material layer 532.

For example, the second light emitting unit 530 includes a second hole transport layer 534, a second light emitting material layer 532, and a second electron transport layer 536 sequentially stacked on the first charge generation layer 560. It can be included.

The third light emitting material layer 542 is a blue light emitting material layer and may include a second blue host and a second blue dopant. The second blue dopant may include at least one of a fluorescent compound, a phosphorescent compound, and a delayed fluorescent compound. In one embodiment, the second blue dopant may be a fluorescent compound.

For example, the second blue host may be the blue host material described above, and the second blue dopant may be the blue dopant material described above.

The third light emitting unit 540 may further include a third hole transport layer 544 located below the third light emitting material layer 542. In addition, the third light emitting unit 540 includes at least one of the third electron transport layer 546 located on the third light emitting material layer 542 and the electron injection layer 548 located on the third electron transport layer 546. You can include one more.

For example, the third light emitting unit 540 includes a third hole transport layer 544, a third light emitting material layer 542, a third electron transport layer 546, which are sequentially stacked on the second charge generation layer 570. It may include an electron injection layer 548.

In the fourth light emitting unit 550, the red light emitting material layer 552 may include a red host and a red dopant. The red host may include a p-type host and an n-type host, and the red dopant may include one of a fluorescent compound, a phosphorescent compound, and a delayed fluorescent compound. In one embodiment, the red dopant can be a phosphorescent compound.

For example, the red host may be the red host material described above, and the red dopant may be the red dopant material described above.

The fourth light emitting unit 550 may further include a fourth hole transport layer 554 located below the fourth light emitting material layer 552. In addition, the fourth light emitting unit 550 includes at least one of a hole injection layer 556 located below the fourth hole transport layer 554 and a fourth electron transport layer 558 located above the fourth light emitting material layer 552. It may further include.

The hole injection layer 556 may include the hole injection material described above and may have a thickness of 10 to 100 Å. For example, the hole -injected layer 556 can have a thickness of 20 mP, 25 m, 30 å, 35 må, 40 m, 45å, 50 mP, 55 å, 60 å, 65å, 70 å, 75å, 80 å, 85 å, 90 å, 95å, there is.

The second hole transport layer 534 of the second light emitting part 530, the third hole transport layer 544 of the third light emitting part 540, and the fourth hole transport layer 554 of the fourth light emitting part 550 are each single It has a layered structure. That is, the first hole transport layer 520 located between the first light-emitting material layer 512, which is a blue light-emitting material layer, and the first electrode 210 has a double-layer structure of the high refractive index layer 522 and the low refractive index layer 526. On the other hand, a second hole transport layer 534 located between the second light-emitting material layer 532, which is a green light-emitting material layer, and the first charge generation layer 560, and a third light-emitting material layer 542, which is a blue light-emitting material layer. and a third hole transport layer 544 located between the second charge generation layer 570, and a fourth hole transport layer located between the fourth light emitting material layer 552, which is a red light emitting material layer, and the first electrode 210. (554) Each has a single-layer structure.

Each of the second hole transport layer 534, the third hole transport layer 544, and the fourth hole transport layer 554 may include the hole transport material described above. In one embodiment, each of the second hole transport layer 534, the third hole transport layer 544, and the fourth hole transport layer 554 may include a compound of Formula 6.

In one embodiment, the refractive index of the hole transport material forming the second hole transport layer 534, the refractive index of the hole transport material forming the third hole transport layer 544, and the refractive index of the hole transport material forming the fourth hole transport layer 554, respectively. may be smaller than the refractive index of the first hole transport material 524 forming the high refractive index layer 522 and may be greater than the refractive index of the second hole transport material 528 forming the low refractive index layer 526.

The thickness of the second hole transport layer 534, the third hole transport layer 544, and the fourth hole transport layer 554 may each be smaller than the thickness of the first hole transport layer 520. For example, each of the second hole transport layer 534 and the fourth hole transport layer 554 may have a thickness of 50 to 200 Å, preferably 50 to 100 Å, and the third hole transport layer 544 may have a thickness of 700 to 800 Å. It can have thickness. For example, the second hole transport layer 534 may have a thickness of 50Å, 75Å, 100Å, 125Å, 150Å, 175Å, or 200Å, and the third hole transport layer 544 may have a thickness of 700Å, 725Å, 750Å, 775Å, or It can have a thickness of 800Å.

Each of the first to fourth electron transport layers 516, 536, 546, and 558 may include the electron transport material described above. Each of the first to fourth electron transport layers 516, 536, 546, and 558 may have a thickness of 100 to 500 Å, preferably 100 to 300 Å. For example, the first to fourth electron transport layers (516, 536, 546, 558) each have 150Å, 175Å, 200Å, 225Å, 250Å, 275Å, 300Å, 350Å, 375Å, 400Å, 425Å, 450Å, 75Å, or 500Å It can have a thickness of

, 바람직하게는 1 내지 10

의 두께를 가질 수 있다. 예를 들어, 전자주입층(548)은 1Å, 5Å, 10Å, 15Å, 20Å, 25Å, 또는 30Å의 두께를 가질 수 있다.The electron injection layer 548 may include an electron injection material that is one of LiF, CsF, NaF, BaF ₂ , Liq (lithium quinolate), lithium benzoate, and sodium stearate. The electron injection layer 548 is 1 to 30

, preferably 1 to 10

It can have a thickness of For example, the electron injection layer 548 may have a thickness of 1Å, 5Å, 10Å, 15Å, 20Å, 25Å, or 30Å.

The first charge generation layer 560 is located between the first light emitting part 510 and the second light emitting part 530. That is, the first light emitting unit 510 and the second light emitting unit 530 are connected by the first charge generation layer 560. The first charge generation layer 560 may be a PN junction charge generation layer in which the first N-type charge generation layer 562 and the first P-type charge generation layer 564 are bonded.

The first N-type charge generation layer 562 is located between the first electron transport layer 516 and the second hole transport layer 534, and the first P-type charge generation layer 564 is located between the first N-type charge generation layer 562. ) and the second hole transport layer 534.

The first N-type charge generation layer 562 may be made of the above-described N-type charge generation material, and the first P-type charge generation layer 564 may be made of the above-described P-type charge generation material.

The second charge generation layer 570 is located between the second light emitting part 530 and the third light emitting part 540. That is, the second light emitting unit 530 and the third light emitting unit 540 are connected by the second charge generation layer 570. The second charge generation layer 570 may be a PN junction charge generation layer in which a second N-type charge generation layer 572 and a second P-type charge generation layer 574 are bonded.

The second N-type charge generation layer 572 is located between the second electron transport layer 536 and the third hole transport layer 544, and the second P-type charge generation layer 574 is located between the second N-type charge generation layer 572. ) and the third hole transport layer 544.

The second N-type charge generation layer 572 may be made of the above-described N-type charge generation material, and the second P-type charge generation layer 574 may be made of the above-described P-type charge generation material.

The third charge generation layer 580 is located between the first light emitting part 510 and the fourth light emitting part 550. That is, the first light emitting unit 510 and the fourth light emitting unit 550 are connected by the third charge generation layer 580. The third charge generation layer 580 may be a PN junction charge generation layer in which a third N-type charge generation layer 582 and a third P-type charge generation layer 584 are bonded.

The third N-type charge generation layer 582 is located between the fourth electron transport layer 558 and the first hole transport layer 520, and the third P-type charge generation layer 584 is located between the third N-type charge generation layer 582. ) and the first hole transport layer 520.

The third N-type charge generation layer 582 may be made of the above-described N-type charge generation material, and the third P-type charge generation layer 584 may be made of the above-described P-type charge generation material.

As described above, the organic light emitting diode (D3) of the present invention includes a first light emitting material layer (512) that is a blue light emitting material layer, a first light emitting portion (510) including a first hole transport layer (520), and a green light emitting material layer. The second light emitting part 530 includes the second light emitting material layer 532, which is a material layer, and is located between the first light emitting part 510 and the second electrode 230, and the third light emitting material is a blue light emitting material layer. It includes a third light-emitting portion 540 that includes a layer 542 and is located between the second light-emitting portion 530 and the second electrode 230, and a fourth light-emitting material layer 552 that is a red light-emitting material layer. It includes a fourth light emitting part 550 located between the first light emitting part 510 and the first electrode 210, and the first hole transport layer 520 includes a high refractive index layer 522 and a low refractive index layer 526. Includes. Therefore, in the organic light emitting diode (D3) of the present invention, blue light emission efficiency is improved and color viewing angle is improved.

[Organic light emitting diode 1]

Anode (ITO), hole injection layer, first hole transport layer, blue light emitting material layer, first electron transport layer, first n-type charge generation layer, first p-type charge generation layer, second hole transport layer, red light emitting material layer, A green light-emitting material layer, a second electron transport layer, a second n-type charge generation layer, a second p-type charge generation layer, a third hole transport layer, a blue light-emitting material layer, a third electron transport layer, an electron injection layer, and a cathode (Al). A white organic light emitting diode was produced by stacking.

1. Comparative example

(1) Comparative Example 1 (Ref1)

A first hole transport layer (1000 Å) was formed using the compound of Formula 6.

(2) Comparative Example 2 (Ref2)

A second hole transport layer was formed by sequentially stacking a high refractive index layer (30 Å) using the compound of Chemical Formula 1 and a low refractive index layer (45 Å) using the compound of Chemical Formula 3.

(3) Comparative Example 3 (Ref3)

A third hole transport layer was formed by sequentially stacking a high refractive index layer (220 Å) using the compound of Formula 1 and a low refractive index layer (340 Å) using the compound of Formula 3.

[Formula 6]

2. Experimental Example 1 (Ex1)

A first hole transport layer was formed by sequentially stacking a high refractive index layer (400 Å) using the compound of Formula 1 and a low refractive index layer (600 Å) using the compound of Formula 3.

Comparative Examples 1 to 3, efficiency (cd/A), blue index (BI=cd/A(B)/By), viewing angle (△u'v'), external of the organic light emitting diode manufactured in Experimental Example 1 Quantum efficiency (EQE (%)) was measured and listed in Table 2.

Additionally, the EL spectra of the organic light emitting diodes manufactured in Comparative Examples 1 to 3 and Experimental Example 1 are shown in Figures 6 to 9, respectively.

[Table 2]

As shown in Table 2, compared to Comparative Example 1 in which all of the first to third hole transport layers have a single layer structure, the second hole transport layer located below the red and green light-emitting material layers has a high refractive index layer and a low refractive index layer. In the organic light emitting diodes of Comparative Example 2, which has a double-layer structure, and Comparative Example 3, where the third hole transport layer located below the blue light-emitting material layer adjacent to the cathode has a double-layer structure of a high refractive index layer and a low refractive index layer, the light emission characteristics are not improved. .

However, in the organic light emitting diode of Experimental Example 1, where the first hole transport layer located below the blue light emitting material layer adjacent to the anode has a double layer structure of a high refractive index layer and a low refractive index layer, blue light emission efficiency is improved and the viewing angle is greatly improved.

That is, the first hole transport layer of the first light emitting part adjacent to the anode and including a blue light emitting material layer has a double layer structure of a high refractive index layer and a low refractive index layer, and the second hole transport layer of the second light emitting part includes red and green light emitting material layers. When each of the third hole transport layers of the third light emitting part adjacent to the cathode and including the blue light emitting material layer has a single layer structure, the blue light emission efficiency of the organic light emitting diode and the organic light emitting display device including the same is improved and the color viewing angle is improved. It improves.

3. Experimental Example 2

In the organic light emitting diode of Experimental Example 1, the thickness of the high refractive layer (HTL1-1) and the low refractive layer (HTL1-2) were changed, and the efficiency (cd/A) and blue index (BI=cd/A) of the organic light emitting diode were changed. (B)/By), viewing angle (△u'v'), and external quantum efficiency (EQE (%)) were measured and listed in Tables 3 and 4.

[Table 3]

[Table 4]

As shown in Tables 3 and 4, the first hole transport layer located below the blue light-emitting material layer adjacent to the anode has a double-layer structure of a high refractive index layer (HTL1-1) and a low refractive index layer (HTL1-2), and has a high refractive index. When the thickness of the layer (HTL1-1) is smaller than the thickness of the low refractive layer (HTL1-2), the blue light emission efficiency of the organic light emitting diode increases and the color viewing angle is improved. For example, the thickness of the high refractive index layer (HTL1-1) may be in the range of 200 to 500 Å, preferably in the range of 300 to 450 Å, and the thickness of the low refractive index layer (HTL1-2) may be in the range of 500 to 800 Å, preferably 550 to 550 Å. It may be in the range of 700Å.

4. Experimental Example 3

In the organic light emitting diode of Experimental Example 1, the refractive index of the high refractive index layer (350Å) and the refractive index of the low refractive layer (650Å) were changed, and the efficiency of the organic light emitting diode (cd/A) and blue index (BI=cd/A(B)/ By), viewing angle (△u'v'), and external quantum efficiency (EQE (%)) were measured and listed in Table 5.

[Table 5]

As shown in Table 5, when the difference between the refractive index of the high refractive index layer (HTL1-1) and the low refractive index layer (HTL1-2) is more than 0.1, the blue light emission efficiency of the organic light emitting diode increases and the color viewing angle is improved. For example, the difference between the refractive index of the high refractive index layer (HTL1-1) and the low refractive index layer (HTL1-2) may be 0.1 or more and 0.25 or less, preferably 0.15 or more and 0.25 or less.

5. Experimental Example 4

In the organic light emitting diode of Experimental Example 1, the refractive index of the high refractive index layer (400Å) and the refractive index of the low refractive layer (600Å) were changed, and the efficiency of the organic light emitting diode (cd/A) and blue index (BI=cd/A(B)/ By), viewing angle (△u'v'), and external quantum efficiency (EQE (%)) were measured and listed in Table 6.

[Table 6]

As shown in Table 6, when the difference between the refractive index of the high refractive index layer (HTL1-1) and the low refractive index layer (HTL1-2) is more than 0.1, the blue light emission efficiency of the organic light emitting diode increases and the color viewing angle is improved. For example, the difference between the refractive index of the high refractive index layer (HTL1-1) and the low refractive index layer (HTL1-2) may be 0.1 or more and 0.25 or less, preferably 0.15 or more and 0.25 or less.

[Organic light emitting diode 2]

Anode (ITO), hole injection layer, first hole transport layer, blue light emitting material layer, first electron transport layer, first n-type charge generation layer, first p-type charge generation layer, second hole transport layer, red light emitting material layer, A white organic light-emitting diode was manufactured by stacking a green light-emitting material layer, a second electron transport layer, an electron injection layer, and a cathode (Al).

6. Comparative Example 4 (Ref4)

A first hole transport layer (1000 Å) was formed using the compound of Formula 6.

7. Experimental Example 5 (Ex5)

A first hole transport layer was formed by sequentially stacking a high refractive index layer (400 Å) using the compound of Chemical Formula 1 and a low refractive index layer (600 Å) using the compound of Chemical Formula 3.

Efficiency (cd/A), blue index (BI=cd/A(B)/By), viewing angle (△u'v'), and external quantum efficiency (EQE) of the organic light emitting diodes produced in Comparative Example 4 and Experimental Example 5 (%)) was measured and listed in Table 7.

[Table 7]

As shown in Table 7, compared to the organic light emitting diode of Comparative Example 4, the first hole transport layer located below the blue light emitting material layer adjacent to the anode of Experimental Example 5 has a double layer structure of a high refractive index layer and a low refractive index layer. In organic light emitting diodes, blue light emission efficiency is improved and viewing angle is greatly improved.

[Organic light emitting diode 3]

Anode (ITO), hole injection layer, fourth hole transport layer, red light emitting material layer, fourth electron transport layer, third n-type charge generation layer, third p-type charge generation layer, first hole transport layer, blue light emitting material layer, 1st electron transport layer, 1st n-type charge generation layer, 1st p-type charge generation layer, 2nd hole transport layer, green light-emitting material layer, 2nd electron transport layer, 2nd n-type charge generation layer, 2nd p-type charge generation A white organic light-emitting diode was manufactured by stacking a layer, a third hole transport layer, a blue light-emitting material layer, a third electron transport layer, an electron injection layer, and a cathode (Al).

8. Comparative Example 5 (Ref5)

A first hole transport layer (590Å) was formed using the compound of Formula 6.

9. Experimental Example 6 (Ex6)

A third hole transport layer was formed by sequentially stacking a high refractive index layer (240 Å) using the compound of Formula 1 and a low refractive index layer (350 Å) using the compound of Formula 3.

Efficiency (cd/A), blue index (BI=cd/A(B)/By), viewing angle (△u'v'), and external quantum efficiency (EQE) of the organic light emitting diode produced in Comparative Example 5 and Experimental Example 6 (%)) was measured and listed in Table 8.

[Table 8]

As shown in Table 8, compared to the organic light emitting diode of Comparative Example 5, the first hole transport layer located below the blue light emitting material layer adjacent to the anode of Experimental Example 6 has a double layer structure of a high refractive index layer and a low refractive index layer. In organic light emitting diodes, blue light emission efficiency is improved and viewing angle is greatly improved.

[Organic light emitting diode 4]

Anode (ITO), hole injection layer, first hole transport layer, blue light emitting material layer, first electron transport layer, first n-type charge generation layer, first p-type charge generation layer, second hole transport layer, red light emitting material layer, A green light-emitting material layer, a second electron transport layer, a second n-type charge generation layer, a second p-type charge generation layer, a third hole transport layer, a blue light-emitting material layer, a third electron transport layer, an electron injection layer, and a cathode (Al). A white organic light emitting diode was produced by stacking.

10. Comparative example

(1) Comparative Example 6 (Ref6)

A first hole transport layer (850 Å) was formed by co-depositing a compound of Formula 1 and a compound of Formula 5. (Increase ratio of compound of formula 1 and compound of formula 5 = 8:2)

(2) Comparative Example 7 (Ref7)

The compound of Formula 4 was deposited to form a lower layer (340 Å), and the compound of Formula 1 and Formula 5 were co-deposited on the lower layer to form an upper layer (560 Å), thereby forming a first hole transport layer with a double-layer structure. (Increase ratio of compound of formula 1 and compound of formula 5 = 8:2)

(3) Comparative Example 8 (Ref8)

The formula 5 compound was deposited to form a lower layer (340Å), and the formula 1 compound and the formula 5 compound were co-deposited on the lower layer to form an upper layer (560Å), thereby forming a first hole transport layer with a double layer structure. (Increase ratio of compound of formula 1 and compound of formula 5 = 8:2)

10. Experimental example

(1) Experimental Example 7 (Ex7)

A high refractive index layer (340 Å) was formed by depositing a compound of Formula 1, and a low refractive index layer (560 Å) was formed by co-depositing a compound of Formula 2 and a compound of Formula 4 on the high refractive index layer, thereby forming a first hole transport layer with a double layer structure. (Increase ratio of Formula 2 compound and Formula 4 compound = 5:5)

(2) Experimental Example 8 (Ex8)

A high refractive index layer (340 Å) was formed by depositing a compound of Formula 1, and a low refractive index layer (560 Å) was formed by co-depositing a compound of Formula 4 and a compound of Formula 5 on the high refractive index layer, thereby forming a first hole transport layer with a double layer structure. (Increase ratio of Formula 4 compound and Formula 5 compound = 5:5)

(3) Experimental Example 9 (Ex9)

A high refractive index layer (340 Å) was formed by depositing a compound of Formula 1, and a low refractive index layer (560 Å) was formed by co-depositing a compound of Formula 2 and a compound of Formula 5 on the high refractive index layer, thereby forming a first hole transport layer with a double layer structure. (Increase ratio of compound of formula 2 and compound of formula 5 = 5:5)

(10) Experimental Example 10 (Ex10)

A high refractive index layer (340 Å) is formed by co-depositing a compound of Formula 1 and a compound of Formula 2, and a low refractive index layer (560 Å) is formed by co-depositing a compound of Formula 4 and a compound of Formula 5 on the high refractive index layer, thereby forming the first hole of a double-layer structure. A transport layer was formed. (Increase ratio of compound of formula 1 and compound of formula 2 = 7:3, increase ratio of compound of formula 4 and compound of formula 5 = 5:5)

(11) Experimental Example 11 (Ex11)

A high refractive index layer (340 Å) was formed by co-depositing a compound of Formula 1 and a compound of Formula 2, and a low refractive index layer (560 Å) was formed by depositing a compound of Formula 4 on the high refractive index layer to form a first hole transport layer with a double layer structure. (Increase ratio of Formula 1 compound to Formula 2 compound = 7:3)

Efficiency (cd/A), blue color coordinate (CIE (Bx, By), viewing angle (△u'v'), and external quantum of the organic light emitting diodes manufactured in Comparative Examples 6 to 8 and Experimental Examples 7 to 11. Efficiency (EQE (%)) and blue life (B-T95) were measured and listed in Tables 9 and 10.

[Table 9]

[Table 10]

As shown in Table 10, compared to the organic light emitting diode of Comparative Example 6 including a first hole transport layer of a single layer structure, Experimental Examples 7 to 7 in which the first hole transport layer has a double layer structure of a high refractive index layer and a low refractive index layer. In the organic light emitting diode of Experimental Example 10, luminous efficiency and viewing angle characteristics are improved.

In addition, as shown in Tables 9 and 10, even if the first hole transport layer has a double-layer structure of a high refractive index layer and a low refractive index layer, when the high refractive index layer is located on the low refractive index layer, the luminous efficiency and viewing angle of the organic light emitting diode characteristics deteriorate. (Comparative Example 7, Comparative Example 8)

That is, as in the embodiment of the present invention, when the first hole transport layer has a double-layer structure of a high refractive index layer adjacent to the anode and a low refractive index layer adjacent to the cathode, the luminous efficiency and viewing angle characteristics of the organic light emitting diode are improved.

[Organic light emitting diode 5]

Anode (ITO), hole injection layer, first hole transport layer, blue light emitting material layer, first electron transport layer, first n-type charge generation layer, first p-type charge generation layer, second hole transport layer, red light emitting material layer, A green light-emitting material layer, a second electron transport layer, a second n-type charge generation layer, a second p-type charge generation layer, a third hole transport layer, a blue light-emitting material layer, a third electron transport layer, an electron injection layer, and a cathode (Al). A white organic light emitting diode was produced by stacking.

11. Comparative example

(1) Comparative Example 9 (Ref9)

A high refractive index layer (340 Å) was formed by depositing a compound of Formula 1, and a low refractive index layer (560 Å) was formed by co-depositing a compound of Formula 4 and a compound of Formula 5 on the high refractive index layer, thereby forming a second hole transport layer with a double layer structure. (Increase ratio of compound of formula 4 and compound of formula 5 = 5:5)

(2) Comparative Example 10 (Ref10)

A high refractive index layer (340 Å) was formed by depositing a compound of Formula 1, and a low refractive index layer (560 Å) was formed by co-depositing a compound of Formula 4 and a compound of Formula 5 on the high refractive index layer, thereby forming a third hole transport layer with a double layer structure. (Increase ratio of compound of formula 4 and compound of formula 5 = 5:5)

Efficiency (cd/A), blue color coordinate (CIE (Bx, By), viewing angle (△u'v'), external quantum of the organic light emitting diode produced in Comparative Example 6, Comparative Example 9, Comparative Example 10, and Experimental Example 8 Efficiency (EQE (%)) was measured and listed in Table 11.

[Table 11]

As shown in Table 11, compared to Comparative Example 6 in which all of the first to third hole transport layers have a single layer structure, the second hole transport layer located below the red and green light-emitting material layers has a high refractive index layer and a low refractive index layer. In the organic light emitting diodes of Comparative Example 9, which has a double-layer structure, and Comparative Example 10, where the third hole transport layer located below the blue light-emitting material layer adjacent to the cathode has a double-layer structure of a high refractive index layer and a low refractive index layer, the light emission characteristics are not improved. .

However, in the organic light emitting diode of Experimental Example 8, where the first hole transport layer located below the blue light emitting material layer adjacent to the anode has a double layer structure of a high refractive index layer and a low refractive index layer, blue light emission efficiency is improved and the viewing angle is greatly improved.

That is, the first hole transport layer of the first light emitting part adjacent to the anode and including a blue light emitting material layer has a double layer structure of a high refractive index layer and a low refractive index layer, and the second hole transport layer of the second light emitting part includes red and green light emitting material layers. When each of the third hole transport layers of the third light emitting part adjacent to the cathode and including the blue light emitting material layer has a single layer structure, the blue light emission efficiency of the organic light emitting diode and the organic light emitting display device including the same is improved and the color viewing angle is improved. It improves.

Although the present invention has been described above with reference to preferred embodiments, those skilled in the art may make various modifications and changes to the present invention without departing from the technical spirit and scope of the present invention as set forth in the claims below. You will understand that you can do it.

100: Organic light emitting display device 110: Substrate
180: color filter layer 210: cathode
220: organic light emitting layer 230: anode
312, 412, 442, 512, 542: Blue emitting material layer
332a, 432a, 552: Red light-emitting material layer
332b, 432b, 532: Green light-emitting material layer
320, 420, 520: first hole transport layer
322, 422, 522: high refractive index layer 326, 426, 526: low refractive index layer
324, 424, 524: first hole transport material 328, 428, 526: second hole transport material
D, D1, D2, D3: Organic light emitting diode

Claims (19)

a first electrode;
a second electrode facing the first electrode;
a first light emitting unit including a first hole transport layer and a first light emitting material layer, which is a blue light emitting material layer, and located between the first electrode and the second electrode;
It includes a second light emitting material layer including at least one of a red light emitting material layer and a green light emitting material layer and a second light emitting portion located between the first light emitting material and the second electrode,
The first hole transport layer includes a high refractive index layer having a first refractive index and a low refractive index layer having a second refractive index less than the first refractive index and located between the high refractive index layer and the first light emitting material layer.
According to claim 1,
An organic light emitting device, characterized in that the difference between the first refractive index and the second refractive index is 0.05 or more.
According to claim 1,
The high refractive index layer includes at least one of the compound represented by Formula 1 and the compound represented by Formula 2, and the low refractive layer includes a compound represented by Formula 2, a compound represented by Formula 3, and a compound represented by Formula 4, An organic light emitting device comprising at least one of the compounds represented by Formula 5.
[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

According to claim 3,
The low refractive index layer is an organic light emitting device comprising at least one of a compound represented by Formula 3, a compound represented by Formula 4, and a compound represented by Formula 5.
According to claim 3,
The high refractive index layer includes a compound represented by Formula 1 and a compound represented by Formula 2, and the weight ratio of the compound represented by Formula 1 is equal to or greater than the weight ratio of the compound represented by Formula 2. Light emitting device.
According to claim 1,
An organic light emitting device, wherein the high refractive index layer has a first thickness, and the low refractive index layer has a second thickness greater than the first thickness.
According to claim 6,
The organic light emitting device, wherein the first thickness is 20 to 45% of the thickness of the first hole transport layer.
According to claim 1,
The second light emitting unit further includes a second hole transport layer located below the second light emitting material layer,
An organic light emitting device, wherein the second hole transport layer has a single layer structure.
According to claim 8,
An organic light emitting device, characterized in that the refractive index of the hole transport material in the second hole transport layer is smaller than the first refractive index and greater than the second refractive index.
According to claim 1,
It includes a third light-emitting material layer, which is a blue light-emitting material layer, and further includes a third light-emitting portion located between the second light-emitting portion and the second electrode,
The second light emitting material layer includes the red light emitting material layer and the green light emitting material layer.
According to claim 10,
The second light-emitting material layer further includes a yellow-green light-emitting material layer positioned between the red light-emitting material layer and the green light-emitting material layer.
According to claim 10,
The second light emitting unit further includes a second hole transport layer located below the second light emitting material layer,
The third light emitting unit further includes a third hole transport layer located below the third light emitting material layer,
An organic light emitting device, wherein each of the second and third hole transport layers has a single-layer structure.
According to claim 12,
The refractive index of the hole transport material in the second hole transport layer and the refractive index of the hole transport material in the third hole transport layer are each smaller than the first refractive index and greater than the second refractive index.
According to claim 1,
a third light emitting unit including a third light emitting material layer that is a blue light emitting material layer and positioned between the second light emitting unit and the second electrode;
It includes a fourth light-emitting material layer, which is a red light-emitting material layer, and a fourth light-emitting portion located between the first light-emitting portion and the first electrode,
An organic light emitting device, wherein the second light emitting material layer includes a green light emitting material layer.
According to claim 14,
The second light emitting unit further includes a second hole transport layer located below the second light emitting material layer,
The third light emitting unit further includes a third hole transport layer located below the third light emitting material layer,
The fourth light emitting unit further includes a fourth hole transport layer located below the fourth light emitting material layer,
An organic light emitting device, wherein each of the second to fourth hole transport layers has a single layer structure.
According to claim 15,
The refractive index of the hole transport material in the second hole transport layer, the refractive index of the hole transport material in the third hole transport layer, and the refractive index of the hole transport material in the fourth hole transport layer are each smaller than the first refractive index and greater than the second refractive index. Characterized by an organic light emitting device.
According to claim 1,
The second light emitting material layer includes the red light emitting material layer and the green light emitting material layer,
The second light-emitting material layer further includes a yellow-green light-emitting material layer positioned between the red light-emitting material layer and the green light-emitting material layer.
With a substrate;
An organic light emitting device comprising the organic light emitting diode according to any one of claims 1 to 17 located on the substrate.
According to claim 18,
The organic light emitting device further comprises a color filter layer located between the substrate and the organic light emitting diode.