JP2012252863A - Manufacturing method for light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device of top emission type comprised of a combination of a white organic EL element and a resonance structure, capable of achieving a simple manufacturing process and high light extraction efficiency.SOLUTION: A reinforcing conductive film 500 is formed at a step-off portion of a contact hole in a blue light-emitting element U3 to reinforce a transparent electrode layer 15 corresponding to the step-off portion. A reflective film/pixel electrode 12 of a red light-emitting element U1 and a green light-emitting element U2 is formed in the same process as the formation process of the reinforcing conductive film 500.

Description

  The present invention relates to a method for manufacturing a light emitting device using various light emitting elements.

  In recent years, a top emission type light-emitting device in which an organic EL (electroluminescence) element is formed as a light-emitting element on a substrate and light emitted from the light-emitting element is extracted on the side opposite to the substrate has been widely used as a display device for electronic devices. In the top emission method, a reflective layer is formed between one of the first electrodes (for example, an anode) formed on the substrate side and the substrate, with the light emitting element interposed therebetween, and the other second electrode (for example, a cathode) that sandwiches the light emitting element. This is a method of taking out light from the side, and is a method with high light utilization efficiency.

The top emission type light emitting device uses a white organic EL element and has a structure in which light of a predetermined wavelength is resonated between the second electrode and the reflective layer. As a method of adjusting the resonance length of each color, a method of adjusting the film thickness of the transparent film on the substrate side or the film thickness of the transparent conductive film as the first electrode is disclosed (Patent Document 1). According to this method, not only the light extraction efficiency is improved, but also the color purity can be improved, and a display with high image quality can be realized.
In addition, a structure has been proposed in which the wavelength of each color of red, green, and blue is extracted by increasing the film thickness of the organic EL element to about 100 nm and the color purity is increased by a color filter (for example, non-patent literature). 1). In this technique, since it is not necessary to adjust the resonance length for each pixel, the structure is simplified, and further, since a transparent conductive film is not required, an advantage in the manufacturing process can be obtained.

Japanese Patent No. 2797883

SID2010 P-146 / S.Lee, Samsung Mobile Display Co., Ltd

However, the method of Patent Document 1 has a problem in that the number of manufacturing steps increases because it is necessary to change the film thickness of the transparent conductive film for each color of red, green, and blue.
Further, in the method of Non-Patent Document 1, in order to extract light from all the red region, green region, and blue region, the color separation of the red pixel, the green pixel, and the blue pixel must be performed by a color filter or the like. There is. Therefore, there has been a problem that the bandwidth of the emission spectrum on the observation side is widened and the color purity is poor. In addition, when compared in the red, green, and blue wavelength regions, there is a problem that the light extraction efficiency is low. As a result, there is a problem that the power consumption of the light emitting device is increased, which is disadvantageous as panel characteristics.

  Against this backdrop, the present invention solves the problem of improving the light extraction efficiency while simplifying the manufacturing process in a top emission type light emitting device combining a white organic EL element and a resonant structure. It is aimed.

  In order to solve the above problems, a method for manufacturing a light emitting device according to the present invention includes a step of forming a light reflecting film on a substrate for any two pixels, and a step of forming a transparent film on the light reflecting film, A step of forming a transparent electrode layer or a semi-transmissive electrode on the transparent film, a step of forming a reinforcing conductive film on the transparent electrode layer or the semi-transmissive electrode, and the remaining one pixel on the substrate side Forming a light reflecting film functioning as an electrode; forming a light emitting layer on the light reflecting film and the transparent electrode layer or the semi-transmissive electrode; forming a light extraction side electrode on the light emitting layer; A thickness of the light-emitting layer, or a transparent film, a transparent electrode layer, a transparent electrode layer, or a semi-transmissive so as to have a resonance structure in which an optical path length between the light reflecting layer and the light extraction side electrode is adjusted. Adjust electrode film thickness In the method of manufacturing an optical device, the step of forming a reinforcing conductive film on the semi-transmissive electrode and the step of forming a light reflecting film functioning as a substrate-side electrode on the substrate for the remaining one pixel are: It is characterized by being performed in the same process.

  In the present invention, for any two pixels, a reinforcing conductive film is formed on the transparent electrode layer or the semi-transmissive electrode, so that even when the transparent electrode layer or the semi-transmissive electrode is thin, the conduction failure is prevented. Thus, a good light emitting function can be exhibited. In addition, the step of forming the reinforcing conductive film on the transparent electrode layer or the semi-transmissive electrode and the step of forming the light reflecting film functioning as the substrate side electrode on the substrate for the remaining one pixel are the same step. Since it is performed, the risk that the reflectance of the light reflecting film functioning as the substrate-side electrode is lowered due to process damage can be reduced. As a result, the pixel of at least one color has a resonance structure in which the light reflection layer functions well as a substrate side electrode and the optical path length between the light reflection layer and the light extraction side electrode is adjusted. The light extraction efficiency can be increased and the power consumption can be reduced while simplifying the manufacturing process.

  As a method for manufacturing a light emitting device according to the present invention, the step of forming the light emitting layer is performed in a predetermined manner so that a resonance structure is formed between the light reflecting film functioning as the substrate side electrode and the light extraction side electrode. The step of forming the light emitting layer with a film thickness of

  In the method for manufacturing a light emitting device according to the present invention, the optical path length of the resonant structure is adjusted by the film thickness of the light emitting layer, so that the manufacturing process can be simplified, and the light extraction efficiency can be improved and the power consumption can be improved. Can be reduced.

  As a method for manufacturing a light emitting device according to the present invention, the step of forming the transparent film may be a step of forming the transparent film with a predetermined film thickness so as to adopt a resonance structure in a pixel forming the transparent film. it can.

  In the method for manufacturing a light emitting device according to the present invention, since the optical path length of the resonant structure is adjusted by the film thickness of the transparent conductive film or transparent film, light emission with high color purity and wide color gamut is achieved while improving light extraction efficiency. Equipment can be provided.

  As a method for manufacturing a light emitting device according to the present invention, the step of forming the light emitting layer may be a step of forming the light emitting layer with the same film thickness for each pixel of each color.

  In the method for manufacturing a light emitting device according to the present invention, since the configuration of the light emitting layer is the same for each pixel of each color, the manufacturing process can be simplified and the optical path length can be adjusted by the film thickness of the light emitting layer. The light extraction efficiency can be increased.

  As a method for manufacturing a light emitting device according to the present invention, the step of forming the transflective electrode is a step of forming the transflective electrode with a material having an extinction coefficient of 3.0 or less with respect to a wavelength of 400 nm to 600 nm. You can also.

  In the method for manufacturing a light emitting device according to the present invention, the extinction coefficient of the transflective electrode is 3.0 or less with respect to a wavelength of 400 nm to 600 nm, so the reflectance at the interface with the hole injection layer is low, and the extinction A metal material having a low coefficient can be used, and a light emitting device can be manufactured in a semiconductor manufacturing line, for example, a manufacturing line using Si.

  As a method for manufacturing a light emitting device according to the present invention, the step of forming the transflective electrode may be a step of forming the transflective electrode with TiN. In the method for manufacturing a light emitting device according to the present invention, since the transflective electrode is TiN, a metal material having a low reflectance at the interface with the hole injection layer and a low extinction coefficient can be used. For example, a light emitting device can be manufactured in a manufacturing line using Si.

  As a method for manufacturing a light emitting device according to the present invention, the step of forming the semi-transmissive electrode may be a step of forming the semi-transmissive electrode from a semiconductor material. In the method for manufacturing a light emitting device according to the present invention, since the transflective electrode is a semiconductor material, a metal material having a low reflectance at the interface with the hole injection layer and a low extinction coefficient can be used. For example, a light emitting device can be manufactured in a manufacturing line using Si.

  As a method for manufacturing a light emitting device according to the present invention, the step of forming the transflective electrode may be a step of forming the transflective electrode from polycrystalline Si or amorphous Si doped with impurities. In the method for manufacturing a light emitting device according to the present invention, since the transflective electrode is polycrystalline Si or amorphous Si doped with impurities, a metal material having a low reflectance at the interface with the hole injection layer and a low extinction coefficient is used. The light emitting device can be manufactured in a semiconductor manufacturing line, for example, a manufacturing line using Si.

  The method for manufacturing a light emitting device according to the present invention may further include a step of forming a hole injection film between the semi-transmissive electrode and the light emitting layer. In the method for manufacturing a light emitting device according to the present invention, holes can be appropriately injected into the light emitting layer, and high light extraction efficiency and light emission in a wide color gamut can be realized.

In the method for manufacturing a light emitting device according to the present invention, the step of forming the hole injection film may be a step of forming the hole injection film with an oxide, particularly MoO ₃ . In the method for manufacturing a light emitting device according to the present invention, since the hole injection layer is an oxide, in particular, MoO ₃ , it is possible to appropriately inject holes into the light emitting layer, and in a high light extraction efficiency and a wide color gamut. Light emission can be realized.

  As a method of manufacturing a light emitting device according to the present invention, the step of forming the reinforcing conductive film and the step of forming a light reflecting film functioning as the substrate-side electrode are made of Al, Ag, or an alloy material thereof. It can also be set as the process of forming the electrically conductive film for reinforcement, and a light reflection film. In the method for manufacturing a light emitting device according to the present invention, since the substrate side electrode is made of Al, Ag, or an alloy material thereof, the substrate side electrode can be provided with a function as a reflective layer, and light extraction efficiency can be increased. it can.

  As a method for manufacturing a light emitting device according to the present invention, the step of forming the light extraction side electrode may be a step of forming the light extraction side electrode with an alloy material containing an alkali metal or an alkaline earth metal. In the method for manufacturing a light emitting device according to the present invention, since the light extraction side electrode is an alloy material containing an alkali metal or an alkaline earth metal, an appropriate resonance structure is formed between the light emitting layer and the substrate side electrode. Can be realized.

  As a method for manufacturing a light emitting device according to the present invention, the step of forming the light extraction side electrode may be a step of forming the light extraction side electrode with MgAg. In the method for manufacturing a light emitting device according to the present invention, since the light extraction side electrode is MgAg, a resonance structure can be appropriately realized between the light emitting layer and the substrate side electrode.

  The method for manufacturing a light emitting device according to the present invention may further include a step of forming a color filter on an upper layer of the light extraction side electrode. In the method for manufacturing a light emitting device according to the present invention, it is possible to appropriately and efficiently extract the emission colors of the respective colors from the light emitting layer using the white organic EL layer.

It is typical sectional drawing which shows the outline | summary of the light-emitting device which concerns on one Embodiment of this invention. It is a figure which shows the material used for the positive hole transport layer of the OLED layer in FIG. 1, a light emitting layer, and an electron carrying layer. The optical distance from the reflective layer / pixel electrode or transparent electrode layer to the counter electrode is D, the phase shift in reflection at the reflective layer / pixel electrode 12 or transparent electrode layer is φ _L , and the phase shift in reflection at the counter electrode 22 is When φ _U , the standing wave peak wavelength is λ, and the integer is m, D = {(2πm + φ _L + φ _U ) / 4π} λ, the peak wavelength λ is 490 nm, and the integer m is 0-3 It is a figure which shows the relationship of the light extraction efficiency with respect to a wavelength at the time. It is a figure which shows the relationship between the value of the integer m when obtaining each peak wavelength, and optical path length. It is a figure which shows the change of the refractive index with respect to each wavelength of Al, Cu, TiN, Mo, and W. It is a figure which shows the change of the extinction coefficient with respect to each wavelength of Al, Cu, TiN, Mo, and W. The calculation result of the reflectance of the organic EL substance and the metallic material feeling of the OLED layer, and the reflectance for a wavelength of 400 to 600 nm of a typical metallic material used in a semiconductor manufacturing line, for example, a manufacturing line using Si are shown. FIG. It is a figure which shows the characteristic of the color filter used for Example 1, Example 2, Example 3, Example 4, Comparative Example 1, and Comparative Example 2. FIG. It is a figure which shows the power consumption of Example 1, Example 2, Example 3, Example 4, the comparative example 1, and the comparative example 2. FIG. It is a figure which shows the sRGB coverage of Example 1, Example 2, Example 3, Example 4, Comparative Example 1, and Comparative Example 2. FIG. It is process drawing for demonstrating the manufacturing method of the light-emitting device of this embodiment. It is process drawing for demonstrating the manufacturing method of the light-emitting device of this embodiment. It is process drawing for demonstrating the manufacturing method of the light-emitting device of this embodiment. It is process drawing for demonstrating the manufacturing method of the light-emitting device of this embodiment. It is process drawing for demonstrating the manufacturing method of the light-emitting device of this embodiment. It is process drawing for demonstrating the manufacturing method of the light-emitting device of this embodiment. It is process drawing for demonstrating the manufacturing method of the light-emitting device of this embodiment.

Hereinafter, various embodiments according to the present invention will be described with reference to the accompanying drawings. In the drawings, the ratio of dimensions of each part is appropriately changed from the actual one.
<A: Structure of light emitting device>
<A-1: Red light emitting element and green light emitting element>
FIG. 1 is a schematic cross-sectional view showing an outline of a light emitting device D1 according to an embodiment of the present invention. The light emitting device D1 has a configuration in which a plurality of light emitting elements U1, U2, and U3 (corresponding to pixels) are arranged on the surface of the first substrate on the lower side (not shown). In FIG. Only the red light emitting element U1, one green light emitting element U2, and one blue light emitting element U3 are illustrated. The light emitting device D1 of the present embodiment is a top emission type, and the light generated by each light emitting element U1, U2, U3 travels upward in FIG. Therefore, in addition to a light-transmitting plate material such as glass, an opaque plate material such as a ceramic or metal sheet can be employed as the lower first substrate not shown. In addition, although wiring for supplying light to each light emitting element U1, U2, U3 to emit light is arranged on the first substrate, illustration of the wiring is also omitted.

  The red light emitting element U1 and the green light emitting element U2 are a reflective layer / pixel electrode 12 (first electrode: anode) formed on the first substrate and a light extraction side transflective reflection disposed on the pixel electrode 12. A layer / counter electrode 22 (second electrode: cathode) and an OLED layer 16 disposed between the reflective layer / pixel electrode 12 and the counter electrode 22. Details will be described below. The reflective layer / pixel electrode 12 shown in FIG. 1 is formed of a light-reflective material. As this type of material, for example, a single metal such as Al (aluminum), Ag (silver), Au (gold), Cu (copper), or an alloy mainly composed of Au, Cu, or Ag is preferably used. The In the present embodiment, the reflective layer / pixel electrode 12 is made of Al (aluminum) and has a thickness of 100 nm.

As shown in FIG. 1, a hole injection layer (HIL) 20 is formed on the reflective layer / pixel electrode 12. In this embodiment, the hole injection layer 20 is preferably an oxide. In this embodiment, the hole injection layer 20 is made of MoO ₃ (molybdenum trioxide) and has a thickness of 2 nm.

  In this embodiment, the OLED layer 16 as the light emitting functional layer includes a hole transport layer (HTL) 24 formed on the hole injection layer 20 and a hole transport layer as shown in FIG. The light emitting layer 26 is formed on the light emitting layer 26 (EML: Emitting Layer) and the electron transport layer 28 (ETL: Electron Transport Layer) is formed on the light emitting layer 26.

The hole transport layer 24 was formed of α-NPD as shown in FIG. 2, and the film thickness was 25 nm. The light emitting layer 26 is formed of an organic EL material that emits light by combining holes and electrons. The organic EL material is a low-molecular material and emits white light. As shown in FIG. 2, as the red host material, the red dopant material, and the green and blue host materials, those shown in FIG. 2 are used, and DPAVBi is used as the blue dopant material. Quinacridone is used as the green dopant material. In the present embodiment, the thickness of the light emitting functional layer 26 is 50 nm.
As shown in FIG. 2, the electron transport layer 28 was formed of Alq3 (tris 8-quinolinolato aluminum complex) and had a thickness of 25 nm. As described above, the film thickness of the OLED layer 16 formed of the hole transport layer 24, the light emitting layer 26, and the electron transport layer 28 was 100 nm.

  The counter electrode 22 is a cathode and is formed so as to cover the OLED layer 16. The counter electrode 22 is continuous over the plurality of light emitting elements U1, U2, and U3. The counter electrode 22 functions as a transflective layer having a property of transmitting part of the light reaching the surface and reflecting the other part (that is, transflective), such as magnesium or silver. It is formed from a single metal, an alloy containing magnesium or silver as a main component, or an alloy material containing an alkali metal or an alkaline earth metal. In the present embodiment, the counter electrode 22 is made of MgAg (magnesium silver alloy) and has a thickness of 10 nm.

  A sealing film 30 made of an inorganic material is formed on the counter electrode 22 as a protective layer for preventing water and outside air from entering the light emitting elements U1, U2, and U3. The sealing film 30 is formed of an inorganic material having a low gas permeability such as SiN (silicon nitride) or SiON (silicon oxynitride). In this embodiment, the sealing film 30 is made of SiN, and the film thickness is 400 nm.

  In the present embodiment, the upper substrate 31 is disposed so as to face the plurality of light emitting elements U1, U2, U3 formed on the lower substrate. The upper substrate 31 is made of a light transmissive material such as glass. The thickness of the upper substrate 31 was 0.5 mm. A color filter and a light shielding film are formed on the surface of the upper substrate 31 facing the lower substrate. The light shielding film is a film body of a light shielding body in which an opening is formed to face each light emitting element U1, U2, U3. A color filter is formed in the opening.

In the present embodiment, a red color filter 40 that selectively transmits red light is formed in the opening corresponding to the red light emitting element U1. A green color filter 41 that selectively transmits green light is formed in the opening corresponding to the green light emitting element U2.
In the red light emitting element U1 and the green light emitting element U2 of the present embodiment, a resonator that resonates light emitted from the OLED layer 16 between the reflective layer / pixel electrode 12 and the counter electrode 22 as the light extraction side translucent reflective layer. A structure is formed. Thereby, red and green wavelengths of light can be extracted efficiently.
The upper substrate 31 on which the color filter and the light shielding film are formed is bonded to the lower substrate through the sealing film 30.

<A-2: Blue light emitting element>
The blue light emitting element U3 includes a reflective layer 13 formed on the lower substrate, a transparent layer 14 disposed on the reflective layer 13, and a transparent electrode layer (first electrode: anode) disposed on the transparent layer 14 ) 15, a counter electrode 22 (second electrode) as a light extraction side transflective layer, and an OLED layer 16 disposed between the transparent electrode layer 15 and the counter electrode 22. Details will be described below.

  The reflective layer 13 shown in FIG. 1 is formed of a material having light reflectivity. As this type of material, for example, a single metal such as Al (aluminum), Ag (silver), Au (gold), Cu (copper), or an alloy mainly composed of Au, Cu, or Ag is preferably used. The In the present embodiment, the reflective layer 13 is formed of Al (aluminum) similarly to the red light emitting element U1 and the green light emitting element U2, and the film thickness is 100 nm.

The transparent layer 14 is made of SiO ₂ and functions as an optical path adjustment layer. In this example, the film thickness of the transparent layer 14 was 70 nm. The transparent electrode layer 15 is made of ITO (indium tin oxide) and has a thickness of 50 nm.

  The OLED layer 16, the counter electrode 22, the sealing film 30, and the upper substrate 31 in the blue light emitting element U3 have the same configuration as that of the red light emitting element U1 and the green light emitting element U2, and the film thickness is also the same. That is, the OLED layer 16 is set to a thickness of 100 nm, the counter electrode 22 is set to 10 nm, and the sealing film 30 is set to a thickness of 400 nm. The upper substrate 31 has a thickness of 0.5 mm.

A blue color filter 42 that selectively transmits blue light is formed in the opening of the above-described light shielding film corresponding to the blue light emitting element U3. In the blue light emitting element U3, a resonator structure that resonates light emitted from the OLED layer 16 is formed between the transparent electrode layer 15 and the counter electrode 22 as the light extraction side transflective layer. Thereby, the light of a blue wavelength can be taken out efficiently.
The upper substrate on which the color filter and the light shielding film are formed is bonded to the lower substrate via the sealing film 30. The above is the structure of the light-emitting device of this embodiment.

<B: Resonant structure of light emitting device>
Next, the characteristics of the light emitting device D1 of the present embodiment will be described. As described above, in the red light emitting element U1 and the green light emitting element U2, resonance that resonates light emitted from the OLED layer 16 between the reflective layer / pixel electrode 12 and the counter electrode 22 as the light extraction side translucent reflective layer. A vessel structure is formed. In the blue light emitting element U3, a resonator structure that resonates light emitted from the OLED layer 16 is formed between the transparent electrode layer 15 and the counter electrode 22 as the light extraction side transflective layer.

Specifically, the optical distance from the reflective layer / pixel electrode 12 or the transparent electrode layer 15 to the counter electrode 22 is D, and the phase shift in reflection at the reflective layer / pixel electrode 12 or the transparent electrode layer 15 which is the lower electrode is calculated. When φ _L , the phase shift in reflection at the counter electrode 22 which is the upper side electrode is φ _U , the peak wavelength of the standing wave is λ, and the integer is m, the structure satisfies the following formula.
D = {(2πm + φ _L + φ _U ) / 4π} λ (1)

  The red light emitting element U1 and the green light emitting element U2 have an optical structure that satisfies m = 0 in the formula (1). Further, the blue light emitting element U3 has an optical structure satisfying m = 1 in the formula (1).

  FIG. 3 shows the result of calculating the light extraction efficiency when the peak wavelength is 490 nm in each optical structure when m = 0, 1, 2, and 3. This calculation precondition is that the reflective layer / pixel electrode 12 is made of Al with a thickness of 100 nm, the light emitting layer 26 with a thickness of 20 nm, the electron transport layer 28 with a thickness of 40 nm, the counter electrode 22 with MgAg of 10 nm, and The sealing film 30 is made of SiN, the film thickness is set to 400 nm, and the total thickness of the hole injection layer 20 and the hole transport layer 24 is adjusted so that the peak wavelength is 490 nm. The refractive index of each layer between the reflective layer / pixel electrode 12 and the counter electrode 22 is 1.8. As shown in FIG. 3, the optical structure with m = 0 has a wider wavelength range for obtaining high light extraction efficiency than the optical structure with m = 1, 2, and 3. I understand.

FIG. 4 shows the value of m in the above formula (1) and the reflective layer at the red, green, and blue peak wavelengths when the refractive index n of the OLED layer 16 made of organic EL is 1.8. The relationship with the film thickness D from the cum pixel electrode 12 or the transparent electrode layer 15 to the counter electrode 22 is shown.
As shown in FIG. 4, in the optical structure in the case of m = 0, the film thickness range in which the red peak wavelength can be obtained partially overlaps the film thickness range in which the green peak wavelength can be obtained. Recognize. It can also be seen that the film thickness range in which the green peak wavelength can be obtained and the film thickness range in which the blue peak wavelength can be obtained partially overlap. That is, it can be understood that light having a wide bandwidth can be extracted by setting the film thickness D to a predetermined value.
On the other hand, in the optical structure in the case of m = 1, it can be seen that there is no portion overlapping the film thickness range in which the peak wavelength of each color is obtained, and it is necessary to set the film thickness D for each color.

However, when all red, green, and blue light emitting elements are formed to have an optical structure of m = 0, the light extraction efficiency of each color wavelength is low, the power consumption of the light emitting device is high, and the xy color The sRGB coverage in the degree diagram will be reduced.
In addition, when all the red, green, and blue light emitting elements are formed to have an optical structure of m = 1, it is necessary to adjust the film thickness of the transparent electrode for each light emitting element of each color. It will increase.

  Therefore, in this example, red and green light emitting elements were formed to have an optical structure of m = 0, and blue light emitting elements were formed to have an optical structure of m = 1.

<C: Panel simulation>
Hereinafter, a panel simulation performed to confirm the power consumption and the sRGB coverage of the light emitting device D1 of the present embodiment will be described.
In this simulation, Example 1 having the same configuration as that of the light emitting device D1 shown in FIG. 1, Example 2, Example 3 and Example 4 different from the light emitting device D1, and Comparative Example 1 and Comparative Example are compared. The light emitting device of Example 2 was prepared.

<C-1: Structure of Example 1>
Example 1 has the same structure as the light-emitting device D1 shown in FIG. 1, and the material and film thickness of each film of the red light-emitting element U1 and the green light-emitting element U2 are 10 nm. The OLED layer 16 is 100 nm, the MoO ₃ hole injection film 20 is 2 nm, and the Al reflective layer / pixel electrode 12 is 100 nm.
As for the material and film thickness of each film of the blue light emitting element U3, as described above, the MgAg light extraction side electrode 22 is 10 nm, the OLED layer 16 is 100 nm, and the Al reflective film 13 is 100 nm. In Example 1, the transparent electrode layer 15 was formed of ITO, and the film thickness was 50 nm. The transparent film 14 is made of SiO ₂ and has a thickness of 70 nm so that a blue peak wavelength can be obtained.

<C-2: Structure of Example 2>
The light emitting device of Example 2 is the same as Example 1 in that the red light emitting element U1 has an optical structure in the case where m = 0 in the above (1), but the green light emitting element U2 has m = 0. This embodiment differs from the first embodiment in that it has an optical structure in the case of m = 1 instead of the optical structure in the case of. That is, Example 2 has an optical structure when the red light emitting element U1 is m = 0, and an optical structure when the green light emitting element U2 and the blue light emitting element U3 are m = 1.

  The configuration of the layers of the red light emitting element U1 and the material of each layer are the same as those of the red light emitting element U1 of the first embodiment. However, the film thicknesses of the hole transport layer 24 and the electron transport layer 28 were each set to 40 nm in Example 2 while being 25 nm in Example 1 respectively.

The configuration of the layers of the green light emitting element U2 and the blue light emitting element U3 and the material of each layer are the same as those of the blue light emitting element U3 of Example 1. However, the film thicknesses of the hole transport layer 24 and the electron transport layer 28 were each set to 40 nm in Example 2 while being 25 nm in Example 1 respectively.
In Example 2, the thickness of the transparent electrode layer 15 is set to 50 nm for the green light emitting element U2 and 20 nm for the blue light emitting element U2. Thus, Example 2 is different from Example 1 in that the resonance lengths of green and blue are adjusted by changing the film thickness of the transparent electrode layer 15.

<C-3: Structure of Example 3>
In the light emitting device of Example 3, the configuration of the layers of the red light emitting element U1 and the material of each layer are the same as those of the red light emitting element U1 of Examples 1 and 2. The film thicknesses of the hole transport layer 24 and the electron transport layer 28 are set to 40 nm as in the second embodiment.

In the green light-emitting element U2 and the blue light-emitting element U3 of Example 3, a semi-transmissive electrode layer made of TiN (titanium nitride) is used as the first electrode (anode) instead of the transparent electrode layer, and this semi-transmissive electrode layer and the OLED The difference from Example 2 is that a hole injection layer 20 made of MoO ₃ is provided between the layer 16 and the layer 16.
In Example 2, the thickness of the transparent layer 14 was the same in the green light emitting element U2 and the blue light emitting element U3. However, in Example 3, the thickness of the transparent layer 14 in the green light emitting element U2 and the blue light emitting element are the same. It differs from the thickness of the transparent layer 14 of the element U3 and functions as an optical path adjusting layer. In Example 3, the thickness of the transparent layer 14 of the green light emitting element U2 is set to 150 nm, and the thickness of the transparent layer 14 of the blue light emitting element U3 is set to 110 nm.
The configurations of the other layers of the green light emitting element U2 and the blue light emitting element U3 and the materials of the respective layers are the same as those of the blue light emitting element U3 of Example 1. However, the film thicknesses of the hole transport layer 24 and the electron transport layer 28 are each set to 40 nm as in the second embodiment.

  The semi-transmissive electrode layer was formed of TiN (titanium nitride) and the film thickness was 10 nm. As a material suitable for the semi-transmissive electrode layer, it is preferable that the reflectance at the interface with the hole injection layer (HIL) 20 is low and the extinction coefficient is low. FIG. 5 shows the relationship between the refractive index and wavelength of a typical metal material used in a semiconductor production line, for example, a production line using Si, and FIG. 6 shows a semiconductor production line, for example, a production line using Si. The relationship between the extinction coefficient and wavelength of a typical metal material used is shown. The reason why a typical metal material used in a production line using Si is used is that each layer of the light emitting device can be produced in the same production line.

In FIG. 7, the calculation result of the reflectance of the organic EL substance of the OLED layer 16 and a metallic material feeling is shown. The reflectance is calculated by setting the refractive index N ₀ of the organic EL material to 1.8, the extinction coefficient k to 0, the refractive index n ₁ and the extinction coefficient k ₁ as variables, and the following formula (2). {(N ₀ −n ₁ ) ² + k ₁ ² } / {(N ₀ + n ₁ ) ² + k ₁ ² } (2)
Calculated by
FIG. 7 shows the reflectance of a typical metal material used in a semiconductor production line, for example, a production line using Si, with respect to a wavelength of 400 to 600 nm.
In order to reduce the light absorption, a material in a region where the extinction coefficient k is small and the reflectance is low is preferable. The extinction coefficient k is preferably 3.0 or less in the wavelength range of 400 nm to 600 nm. Therefore, it can be seen from FIG. 7 that TiN is preferable among typical metal materials used in the production line using Si. In this example, the transflective electrode layer was formed of TiN, and the film thickness was 10 nm. In addition to TiN, a semiconductor material can be used, and impurity-doped polycrystalline Si or amorphous Si can be used.

The light emitting device in Example 3 has an optical structure when the red light emitting element U1 is m = 0 in the above (1), and has an optical structure when the green light emitting element U2 and the blue light emitting element U3 are m = 1. However, it is the same as the light emitting device of Example 2 described above, but a semi-transmissive electrode layer made of TiN is used as the first electrode (anode), and MoO is interposed between the semi-transmissive electrode layer and the OLED layer 16. ₃ is different from Example 2 in that a hole injection layer 20 made of 3 is provided.
In Example 2, the thickness of the transparent layer 14 was the same in the green light emitting element U2 and the blue light emitting element U3. However, in Example 3, the thickness of the transparent layer 14 in the green light emitting element U2 and the blue light emitting element are the same. It differs from the thickness of the transparent layer 14 of the element U3 and functions as an optical path adjusting layer.

<C-4: Structure of Example 4>
In the light emitting device in Example 4, the configuration of the layers of the red light emitting element U1 and the material of each layer are the same as those of the red light emitting element U1 in Examples 1 to 3. The film thicknesses of the hole transport layer 24 and the electron transport layer 28 are each set to 40 nm, as in the second and third embodiments.
The green light emitting device U2 and the blue light emitting device U3 of Example 4 differ from Example 3 in that a semi-transmissive electrode layer made of Al (aluminum) is used as the first electrode (anode). The film thickness of the transflective electrode layer made of Al (aluminum) was 10 nm.

The light emitting device in Example 4 has an optical structure when the red light emitting element U1 is m = 0 in the above (1), and has an optical structure when the green light emitting element U2 and the blue light emitting element U3 are m = 1. This is the same as the light emitting device of Example 3 described above.
In Example 4, the thickness of the transparent layer 14 of the green light emitting element U2 is different from the thickness of the transparent layer 14 of the blue light emitting element U3, and functions as an optical path adjusting layer. Specifically, the transparent layer 14 of the green light emitting element U2 is set to 160 nm, and the transparent layer 14 of the blue light emitting element U3 is set to 130 nm.

<C-5: Structure of Comparative Example 1>
In Comparative Example 1, all of the red, green, and blue light emitting elements have the same configuration as the blue shipping element U3 in the light emitting device D1 of Example 1. That is, all the red, green and blue light emitting elements were configured to have an optical structure of m = 1, and the thickness of the ITO transparent electrode layer 15 was adjusted for each color.
Specifically, the layer thickness of the transparent electrode layer 15 of the red light emitting element is set to 100 nm, the layer thickness of the transparent electrode layer 15 of the green light emitting element is set to 50 nm, and the layer thickness of the transparent electrode layer 15 of the blue light emitting element is set to 20 nm. ing.
In the blue shipping element U3 of Example 1, the thicknesses of the hole transport layer 24 and the electron transport layer 28 are each set to 25 nm. In Comparative Example 1, the hole transport layers of the light emitting elements of the respective colors are used. The thickness of each of the electron transport layers is set to 40 nm.

<C-6: Structure of Comparative Example 2>
In Comparative Example 2, all the red, green, and blue light emitting elements have the same configuration as the red light emitting element U1 in the light emitting device D1 of Example 1 shown in FIG. 1, and each color emission color is obtained by selecting a color filter. It is a thing. That is, all the red, green, and blue light emitting elements are configured to have an optical structure of m = 0.

<C-7: Color filter>
In this simulation, as shown in FIG. 8, a color filter having a transmittance of 80 to 90% for light of 600 nm or more is used as a red color filter. CF1-R shown in FIG. 8 is for high transmittance, and CF2-R is a color filter for wide color gamut.
As the green color filter, a color filter having a transmittance of 65 to 70% for light of 520 to 560 nm was used. CF1-G shown in FIG. 8 is for high transmittance, and CF2-G is a color filter for wide color gamut.
As the blue color filter, a color filter having a transmittance of 60 to 65% for light of 430 to 470 nm was used. CF1-B shown in FIG. 8 is for high transmittance, and CF2-B is a color filter for wide color gamut.

<C-8: Results of panel simulation>
9 and 10 are diagrams showing the power consumption of Example 1, Example 2, Example 3, Example 4, Comparative Example 1, and Comparative Example 2. FIG. The power consumption is normalized by using CF1 as a color filter in the light emitting device of Comparative Example 1 and displaying 100% as the value when displayed in all white (0.310, 0.310) and 200 cd / m ^2. is there. Further, when CF2 is used as a color filter in the light emitting device of Comparative Example 2, the color specification range is narrow and white display of (0.310, 0.310) is impossible, so the description in FIG. I omitted it.

As shown in FIG. 9, assuming that the power consumption when CF1 is used as the color filter in the light emitting device of Comparative Example 1 is 100%, the power consumption when CF1 is used as the color filter in the light emitting device of Example 1 is as follows. It was 122%, which was 1.22 times that of Comparative Example 1.
Further, assuming that the power consumption when CF1 is used as the color filter in the light emitting device of Comparative Example 1 is 100%, the power consumption when CF2 is used as the color filter in the light emitting device of Comparative Example 1 is 163%. The power consumption in the case where CF2 was used as the color filter in the light emitting device of Example 1 was 187%. That is, the power consumption when CF2 was used as the color filter in the light emitting device of Example 1 was 1.15 times the power consumption when CF2 was used as the color filter in the light emitting device of Comparative Example 1.

  Further, assuming that the power consumption when CF1 is used as the color filter in the light emitting device of Comparative Example 1 is 100%, the power consumption when CF2 is used as the color filter in the light emitting device of Comparative Example 2 is 267%. The power consumption in the case where CF2 was used as the color filter in the light emitting device of Example 1 was 187%. That is, the power consumption when CF2 was used as the color filter in the light emitting device of Example 1 was 0.7 times the power consumption when CF2 was used as the color filter in the light emitting device of Comparative Example 2.

  As described above, the light-emitting device of Example 1 has almost the same performance as the light-emitting device of Comparative Example 1 in terms of power consumption, and the performance superior to that of the light-emitting device of Comparative Example 2 is obtained. It was. As will be described later, the light emitting device of Example 1 can significantly reduce the number of manufacturing steps compared to the light emitting device of Comparative Example 1, and is superior to the light emitting device of Comparative Example 1 in this respect.

Next, regarding the sRGB cover ratio, as shown in FIG. 10, the sRGB cover ratio is 94.4% when CF1 is used as the color filter in the light emitting device of Comparative Example 1. The sRGB coverage when CF1 was used as the color filter was 55.9%. Thus, the sRGB coverage when the CF1 color filter is used in the light emitting device of Example 1 is inferior to that when the CF1 color filter is used in the light emitting device of Comparative Example 1, but it is used for a digital camera or the like. A sufficient sRGB coverage was obtained.
Further, the sRGB cover rate when CF1 is used as the color filter in the light emitting device of Comparative Example 2 is 34.9%, and the sRGB cover is higher when the color filter of CF1 is used in the light emitting device of Example 1. The rate was obtained.

  Further, the sRGB cover ratio when CF2 is used as the color filter in the light emitting device of Comparative Example 1 is 99.1%, and the sRGB cover ratio when CF2 is used as the color filter in the light emitting device of Example 1 is 94. 9%. Thus, the sRGB coverage when the CF2 color filter was used for the light emitting device of Example 1 was almost the same as that when the CF2 color filter was used for the light emitting device of Comparative Example 1.

  Further, the sRGB coverage when CF2 is used as the color filter in the light emitting device of Comparative Example 2 is 74.5%, and the sRGB when the CF2 color filter is used in the light emitting device of Example 1 is much higher. Coverage was obtained.

As described above, the light emitting device of Example 1 has a sufficient sRGB cover rate, although the sRGB cover rate is inferior to the light emitting device of Comparative Example 1 when the CF1 color filter is used. When a CF2 color filter was used, an sRGB coverage rate substantially the same as that of the light emitting device of Comparative Example 1 was obtained. As will be described later, the light emitting device of Example 1 can significantly reduce the number of manufacturing steps compared to the light emitting device of Comparative Example 1, and is superior to the light emitting device of Comparative Example 1 in this respect.
Furthermore, in comparison with the light emitting device of Comparative Example 2, the sRGB coverage was superior to that of the light emitting device of Comparative Example 2.

As shown in FIG. 9, when the power consumption when CF1 is used as the color filter in the light emitting device of Comparative Example 1 is 100%, the power consumption when CF1 is used as the color filter in the light emitting device of Example 2 is as follows. It was 97%, 0.97 times that of Comparative Example 1.
Further, assuming that the power consumption when CF1 is used as the color filter in the light emitting device of Comparative Example 1 is 100%, the power consumption when CF2 is used as the color filter in the light emitting device of Comparative Example 1 is 163%. The power consumption when CF2 was used as a color filter in the light emitting device of Example 2 was 158%. That is, the power consumption when CF2 was used as the color filter in the light emitting device of Example 2 was 0.97 times the power consumption when CF2 was used as the color filter in the light emitting device of Comparative Example 1.

Further, assuming that the power consumption when CF1 is used as the color filter in the light emitting device of Comparative Example 1 is 100%, the power consumption when CF2 is used as the color filter in the light emitting device of Comparative Example 2 is 267%. The power consumption when CF2 was used as a color filter in the light emitting device of Example 2 was 158%. That is, the power consumption when CF2 was used as the color filter in the light emitting device of Example 2 was 0.59 times the power consumption when CF2 was used as the color filter in the light emitting device of Comparative Example 2.
As described above, the light emitting device of Example 2 was superior to the light emitting devices of Example 1, Comparative Example 1, and Comparative Example 2 in terms of power consumption.

Next, regarding the sRGB cover ratio, as shown in FIG. 9, the sRGB cover ratio is 94.4% when CF1 is used as the color filter in the light emitting device of Comparative Example 1, and the light emitting device of Example 2 The sRGB coverage when CF1 was used as the color filter was 88.0%. Thus, the sRGB coverage when the CF1 color filter is used for the light emitting device of Example 2 is inferior to that when the CF1 color filter is used for the light emitting device of Comparative Example 1, but a sufficient sRGB coverage is obtained. was gotten.
Further, the sRGB cover rate when CF1 is used as the color filter in the light emitting device of Comparative Example 2 is 34.9%, and the sRGB cover is higher when the color filter of CF1 is used in the light emitting device of Example 2. The rate was obtained.

Further, the sRGB cover ratio when CF2 is used as the color filter in the light emitting device of Comparative Example 1 is 99.1%, and the sRGB cover ratio when CF2 is used as the color filter in the light emitting device of Example 2 is 94. 3%. Thus, the sRGB coverage when the CF2 color filter was used for the light emitting device of Example 2 was almost the same as that when the CF2 color filter was used for the light emitting device of Comparative Example 1.
Further, the sRGB coverage when CF2 is used as the color filter in the light emitting device of Comparative Example 2 is 74.5%, and the sRGB when the CF2 color filter is used in the light emitting device of Example 2 is much higher. Coverage was obtained.

As described above, the light emitting device of Example 2 has a sufficient sRGB cover rate, although the sRGB cover rate is inferior to the light emitting device of Comparative Example 1 when the CF1 color filter is used. When a CF2 color filter was used, an sRGB coverage rate substantially the same as that of the light emitting device of Comparative Example 1 was obtained.
Furthermore, in comparison with the light emitting device of Comparative Example 2, the sRGB coverage was superior to that of the light emitting device of Comparative Example 2.

As shown in FIG. 9, when the power consumption when CF1 is used as the color filter in the light emitting device of Comparative Example 1 is 100%, the power consumption when CF1 is used as the color filter in the light emitting device of Example 3 is as follows. It was 149%, which was 1.49 times that of Comparative Example 1.
Thus, the power consumption in the case of using CF1 as the color filter is the highest in the power consumption of Example 3 when compared between Comparative Example 1, Example 1, Example 2, and Example 3. I understand that.

Further, assuming that the power consumption when CF1 is used as the color filter in the light emitting device of Comparative Example 1 is 100%, the power consumption when CF2 is used as the color filter in the light emitting device of Comparative Example 1 is 163%. The power consumption in the case where CF2 was used as the color filter in the light emitting device of Example 3 was 247%. That is, the power consumption when CF2 was used as the color filter in the light emitting device of Example 3 was 2.47 times the power consumption when CF2 was used as the color filter in the light emitting device of Comparative Example 1.
Thus, the power consumption when CF2 is used as the color filter is the highest in the power consumption of Example 3 when compared between Comparative Example 1, Example 1, Example 2, and Example 3. I understand that.

Further, assuming that the power consumption when CF1 is used as the color filter in the light emitting device of Comparative Example 1 is 100%, the power consumption when CF2 is used as the color filter in the light emitting device of Comparative Example 2 is 267%. The power consumption in the case where CF2 was used as the color filter in the light emitting device of Example 3 was 247%. That is, the power consumption when CF2 was used as the color filter for the light emitting device of Example 3 was 0.93 times the power consumption when CF2 was used as the color filter for the light emitting device of Comparative Example 2.
Thus, when the power consumption when CF2 is used as the color filter is compared between Comparative Example 2 and Example 3, it can be seen that Example 3 is superior.

  Next, regarding the sRGB coverage, as shown in FIG. 10, the sRGB coverage is 94.4% when CF1 is used as the color filter in the light emitting device of Comparative Example 1, and the light emitting device of Example 3 has the same sRGB coverage. When CF1 was used as the color filter, the sRGB coverage was 92.5%. As described above, the sRGB coverage when the CF1 color filter is used for the light emitting device of Example 3 is inferior to that of the case where the CF1 color filter is used for the light emitting device of Comparative Example 1, but is almost the same as sRGB Coverage was obtained.

  Further, the sRGB cover ratio when CF1 is used as the color filter in the light emitting device of Comparative Example 2 is 34.9%, and the sRGB cover ratio when the color filter of CF1 is used in the light emitting device of Example 3 is 92. Since it is 0.5%, it can be seen that the sRGB coverage is higher in Example 3.

  Further, the sRGB cover ratio when CF2 is used as the color filter in the light emitting device of Comparative Example 1 is 99.1%, and the sRGB cover ratio when 96 is used as the color filter in the light emitting device of Example 3 is 96. 8%. Thus, the sRGB coverage when the CF2 color filter was used for the light emitting device of Example 3 was almost the same as that when the CF2 color filter was used for the light emitting device of Comparative Example 1.

  Further, the sRGB cover ratio when CF2 is used as the color filter in the light emitting device of Comparative Example 2 is 74.5%, and the sRGB cover ratio when the color filter of CF2 is used in the light emitting device of Example 3 is 96. Since it is .8%, it can be seen that the sRGB coverage is much higher in Example 3.

As described above, the light emitting device of Example 3 has almost the same sRGB coverage as that of the light emitting device of Comparative Example 1 both when the CF1 color filter is used and when the CF2 color filter is used. SRGB coverage was obtained.
Furthermore, in comparison with the light emitting device of Comparative Example 2, the performance of Example 3 was superior to that of the light emitting device of Comparative Example 2 in terms of the sRGB cover ratio.
As shown in FIG. 6, when the power consumption when CF1 is used as the color filter in the light emitting device of Comparative Example 1 is 100%, the power consumption when CF1 is used as the color filter in the light emitting device of Example 4 is as follows. It was 257%, 2.57 times that of Comparative Example 1.
Thus, the power consumption when CF1 is used as the color filter is the highest in the power consumption of Example 4 when compared between Comparative Example 1, Example 1, Example 2, Example 3, and Example 4. You can see that it is getting higher.

Further, assuming that the power consumption when CF1 is used as the color filter in the light emitting device of Comparative Example 1 is 100%, the power consumption when CF2 is used as the color filter in the light emitting device of Comparative Example 1 is 163%. When CF2 was used as the color filter in the light emitting device of Example 4, the power consumption was 439%. That is, the power consumption when CF2 was used as the color filter for the light emitting device of Example 4 was 2.69 times the power consumption when CF2 was used as the color filter for the light emitting device of Comparative Example 1.
Thus, the power consumption when CF2 is used as the color filter is the highest in the power consumption of Example 4 when compared between Comparative Example 1, Example 1, Example 2, Example 3, and Example 4. You can see that it is getting higher.

Further, assuming that the power consumption when CF1 is used as the color filter in the light emitting device of Comparative Example 1 is 100%, the power consumption when CF2 is used as the color filter in the light emitting device of Comparative Example 2 is 267%. When CF2 was used as the color filter in the light emitting device of Example 4, the power consumption was 439%. That is, the power consumption when CF2 was used as the color filter for the light emitting device of Example 4 was 1.64 times the power consumption when CF2 was used as the color filter for the light emitting device of Comparative Example 2.
Thus, it can be seen that the power consumption when CF2 is used as the color filter is higher in Example 4 than in Comparative Example 2.

  As described above, the red light emitting element U1 has a zero-order resonance structure, the green light emitting element U2 and the blue light emitting element U3 have a primary resonance structure, and the extinction coefficient is applied to the transflective electrodes of the green light emitting element U2 and the blue light emitting element U3. When TiN, which is a low conductive material, is used, a wide color display can be realized although the power consumption is slightly increased. Moreover, since transparent conductivity, such as ITO, is not required, it can manufacture in a semiconductor manufacturing line, for example, the manufacturing line using Si.

<D: Manufacturing method of light emitting device>
Next, the manufacturing method of the light-emitting device of this embodiment is demonstrated based on FIGS. First, as shown in FIG. 11A, the circuit element thin film 11 and the interlayer insulating film 301 are formed on the first substrate 10. In any of these film formations, a known film formation method such as a PVD method, a CVD method, or a sputtering method, or a photolithography method is appropriately used. At that time, since the formation of the circuit element thin film 11 includes the manufacture of a TFT (Thin Film Transistor), a doping process or the like to the semiconductor layer is also performed. In the formation of the insulating film 301, the contact hole 360 is formed there. In order to form the film, an appropriate etching process or the like is also performed.

  Next, as shown in FIG. 11B, Al is formed by sputtering so as to be in contact with the circuit element thin film 11 of each color light emitting element, and patterned by photolithography and wet etching or dry etching, and the resist is peeled off. To form a contact hole 360. In the blue light emitting element U3, the Al film is extended to the light emitting region, and the reflective film 13 is formed.

Subsequently, as shown in FIG. 12A, the concave portion of the contact hole 360 is filled with an insulating film 302 of SiO ₂ . As shown in FIG. 12B, in order to form the transparent film 14 on the reflective film 13 of the blue light emitting element U3, the resist is peeled off, and SiO ₂ is formed by the CVD method. The deposited SiO ₂ is patterned by photolithography and wet etching or dry etching, and the resist is removed. In this way, the transparent film 14 is formed on the reflective film 13 of the blue light emitting element U3. In forming the transparent film 14, an appropriate etching process or the like is also performed in order to form a contact hole therein.

Next, as shown in FIG. 13A, in the blue light emitting element U3, a TiN conductive layer 490 is formed in order to improve the electrical connection between the contact hole 360 and the transparent electrode layer 15.
In order to form the transparent electrode layer 15 on the transparent film 14 and the conductive layer 490 of the blue light emitting element U3, the resist is peeled off, and ITO is formed by vapor deposition or the like. The deposited ITO is patterned by photolithography and wet etching or dry etching, and the resist is removed. In this way, as shown in FIG. 13B, the transparent electrode layer 15 is formed on the transparent film 14 and the conductive layer 490 of the blue light emitting element U3. The film thickness of the transparent electrode layer 15 is preferably as thin as possible in a range that can ensure conductivity.

  Subsequently, as shown in FIG. 14A, the reflective film / pixel electrode 12 is formed on the interlayer insulating film 301 of the red light emitting element U1 and the green light emitting element U2, and the transparent film 14 contact of the blue light emitting element U3 is contacted. In order to reinforce the transparent electrode layer 15 formed in the hole portion, a reinforcing conductive film 500 is formed. The reflective film / pixel electrode 12 and the reinforcing conductive film 500 are formed by depositing Al by sputtering, patterning by photolithography and wet etching or dry etching, and removing the resist.

The film thickness of the transparent electrode layer 15 is preferably thin as long as the conductivity can be ensured. However, the film thickness becomes thin at the step portion of the contact hole only with the thin conductive film. However, by forming the reinforcing conductive film 500 at the location as in the present embodiment, conduction failure can be reliably prevented.
In addition, in the present embodiment, since the reflective film and pixel electrode 12 of the red light emitting element U1 and the green light emitting element U2 are formed in the same process as the formation process of the reinforcing conductive film 500, the reflective film 13 of the blue light emitting element U3 is formed. Compared with the case where the reflective film / pixel electrode 12 is formed in the same process as the forming process, the risk that the reflectance is lowered can be reduced.
That is, when the reflective film and pixel electrode 12 is formed in the same process as the process of forming the reflective film 13 of the blue light emitting element U3, the reflective film is formed while the transparent film 14 and the transparent electrode layer 15 of the blue light emitting element U3 are formed. In other words, the surface of the pixel electrode 12 is exposed. As a result, the reflectivity of the reflective film / pixel electrode 12 may decrease due to process damage caused by plasma or the like during etching in the process of forming the transparent film 14 and the transparent electrode layer 15.
However, in this embodiment, since the reflective film and pixel electrode 12 of the red light emitting element U1 and the green light emitting element U2 is formed in the same process as the forming process of the reinforcing conductive film 500, the transparent film 14 and the transparent film of the blue light emitting element U3 are formed. Even during the step of forming the electrode layer 15, the surface of the reflective film / pixel electrode 12 is not exposed, so that the risk of a decrease in the reflectance of the reflective film / pixel electrode 12 due to process damage can be reduced.

Next, MoO ₃ is deposited by vapor deposition so as to cover the reflective film / pixel electrode 12 to form a hole injection film 20 as shown in FIG. Further, as shown in FIG. 15A, an isolation film 303 made of SiO ₂ is formed on the contact hole of each color light emitting element, and as shown in FIG. 15B, the hole injection film 20 and the transparent electrode are formed. An OLED layer 16 is formed by vapor deposition so as to cover the layer 15. Further, as shown in FIG. 16, MgAg is formed by vapor deposition to form the light extraction side electrode 22.

  Subsequently, as shown in FIG. 17, SiN is formed by a CVD method to form a sealing film 30. Further, red, green, and blue color filters 40, 41, and 42 and a light shielding film 32 are formed thereon by photolithography. Then, the second substrate 31 is bonded. The above is the manufacturing method of the light emitting device D1 of the present embodiment.

  As described above, in the light emitting device D1 of the present embodiment, the red light emitting element U1 and the green light emitting element U2 are formed so as to have an optical structure when m = 0 in the above formula (1), and the blue light emitting element U3 is formed. In the above formula (1), ITO is used for the transparent electrode layer 15 of the blue light emitting element U3, which is formed so as to have an optical structure in the case of m = 1. Therefore, it is possible to realize a display with a high sRGB coverage while suppressing power consumption.

  Even when the transparent electrode layer 15 is formed with a small film thickness, the reinforcing conductive film 500 is formed at the stepped portion of the contact hole, so that poor conduction can be reliably prevented. In addition, since the reflective film and pixel electrode 12 of the red light emitting element U1 and the green light emitting element U2 is formed in the same process as the forming process of the reinforcing conductive film 500, in the same process as the reflective film 13 of the blue light emitting element U3. Compared with the case where the reflective film / pixel electrode 12 is formed, it is possible to reduce the risk that the reflectance is lowered due to process damage caused by plasma or the like during etching.

  In Example 1 described above, the red light emitting element and the green light emitting element have the optical structure of m = 0 in the above (1), and the blue light emitting element has the optical structure of m = 1 in the above (1). explained. In other embodiments, the light emitting element of any color has an optical structure of m = 0 in the above (1), and the light emitting element of any color has an optical structure of m = 1 in the above (1). However, the present invention is not limited to such a case, and an optical structure in which the value of m in (1) is set to other values may be adopted.

  Furthermore, in the above-described embodiment, after forming the transparent electrode layer of the blue light emitting element, the reinforcing conductive film of the transparent electrode layer and the reflective film and pixel electrode of the red light emitting element and the green light emitting element are formed in the same process. An example was described. However, the present invention is not limited to such a case, and after forming the transparent electrode layer of the light emitting element of any two colors, the reflective conductive film of the transparent electrode layer and the reflection of the light emitting element of the remaining color The film and pixel electrode may be formed in the same process.

  Further, in the embodiment of the manufacturing method described above, the example of forming the transparent electrode layer has been described. However, the present invention is not limited to this case, and a transflective electrode layer is formed instead of the transparent electrode layer. It is also applicable to cases. In this case, it is not necessary to provide the conductive layer 490 for conducting the transparent electrode layer and the reflective layer.

  In the embodiment described above, ITO has been described as an example of the transparent electrode layer 15 of the blue light emitting element U3. However, the present invention is not limited to this, and a transflective electrode using TiN instead of ITO. A layer may be formed. ITO tends to generate particles in the manufacturing process, but TiN does not have such a problem. For this reason, the light emitting device D1 can be manufactured by a semiconductor manufacturing process, for example, a Si process. In this case, it is not necessary to provide the conductive layer 490 for conducting the transparent electrode layer and the reflective layer.

DESCRIPTION OF SYMBOLS 10 ... 1st board | substrate, 11 ... Circuit element thin film, 12 ... Reflective layer and pixel electrode, 13 ... Reflective film, 14 ... Transparent film, 15 ... Transparent electrode layer, 16 ... OLED layer, 20 ... DESCRIPTION OF SYMBOLS ... Hole injection film, 22 ... Counter electrode, 24 ... Hole transport film, 26 ... Laminated light emitting layer, 28 ... Electron transport film, 30 ... Sealing film, 31 ... Second substrate, 40 ... Red color filter, 41... Green color filter, 42... Blue color filter, 301... Interlayer insulating film, 360... Contact hole, 500. ... Red light emitting element, U2 ... Green light emitting element, U3 ... Blue light emitting element

Claims (14)

Forming a light reflecting film on the substrate for any two pixels;
Forming a transparent film on the light reflecting film;
Forming a transparent electrode layer or a semi-transmissive electrode on the transparent film;
Forming a reinforcing conductive film on the transflective electrode;
Forming a light reflecting film functioning as a substrate-side electrode on the substrate for the remaining one pixel;
Forming a light emitting layer on the light reflecting film and the transparent electrode layer or the semi-transmissive electrode;
Forming a light extraction side electrode on the light emitting layer,
The film thickness of the light emitting layer or the film thickness of the transparent film, the transparent electrode layer, or the semi-transmissive electrode is adjusted so as to have a resonance structure in which the optical path length between the light reflecting layer and the light extraction side electrode is adjusted. A method of manufacturing a light emitting device,
The step of forming the reinforcing conductive film on the transparent electrode layer or the semi-transmissive electrode and the step of forming the light reflecting film functioning as the substrate side electrode on the substrate for the remaining one pixel are performed in the same step. Called
A method for manufacturing a light-emitting device.   The step of forming the light emitting layer is a step of forming the light emitting layer with a predetermined film thickness so as to take a resonance structure between the light reflecting film functioning as the substrate side electrode and the light extraction side electrode. The method for manufacturing a light-emitting device according to claim 1.   3. The step of forming the transparent film is a step of forming the transparent film with a predetermined film thickness so as to adopt a resonance structure in a pixel that forms the transparent film. Method for manufacturing the light emitting device.   4. The manufacturing method of a light emitting device according to claim 1, wherein the step of forming the light emitting layer is a step of forming the light emitting layer with the same film thickness for each color pixel. Method.   The step of forming the transflective electrode is a step of forming the transflective electrode with a material having an extinction coefficient of 3.0 or less with respect to a wavelength of 400 nm to 600 nm. 5. A method for manufacturing a light emitting device according to any one of 4 above.   6. The method for manufacturing a light-emitting device according to claim 1, wherein the step of forming the transflective electrode is a step of forming the transflective electrode from TiN.   6. The method for manufacturing a light-emitting device according to claim 1, wherein the step of forming the transflective electrode is a step of forming the transflective electrode from a semiconductor material.   6. The light emitting device according to claim 1, wherein the step of forming the transflective electrode is a step of forming the transflective electrode from polycrystalline Si or amorphous Si doped with impurities. Device manufacturing method.   9. The method of manufacturing a light emitting device according to claim 1, further comprising a step of forming a hole injection film between the semi-transmissive electrode and the light emitting layer. Wherein the step of forming the hole injection layer include oxides, in particular, the method of manufacturing the light emitting device according to claim 9, wherein the step is a step of forming the hole injection layer at MoO _3.   The step of forming the reinforcing conductive film and the step of forming the light reflecting film functioning as the substrate side electrode include the step of forming the reinforcing conductive film and the light reflecting film with Al, Ag, or an alloy material thereof. The method for manufacturing a light emitting device according to claim 1, wherein:   12. The step of forming the light extraction side electrode is a step of forming the light extraction side electrode with an alloy material containing an alkali metal or an alkaline earth metal. Method for manufacturing the light emitting device.   12. The method for manufacturing a light emitting device according to claim 1, wherein the step of forming the light extraction side electrode is a step of forming the light extraction side electrode with MgAg. The method for manufacturing a light emitting device according to claim 1, further comprising a step of forming a color filter on an upper layer of the light extraction side electrode.

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