KR102587011B1 - Oled having internal light extracting photonic crystal structure, internal light scattering layer, external light scattering layer and external quantum dot layer - Google Patents

Abstract

The present invention relates to an organic light-emitting layer that receives electrons and holes and generates light of a specific wavelength, a cathode formed at the top of the organic light-emitting layer to supply electrons to the organic light-emitting layer, and a cathode formed at the bottom of the organic light-emitting layer to generate light of a specific wavelength. An anode that supplies holes to the light-emitting layer and transmits light generated from the organic light-emitting layer, and is formed in a specific partial area at the bottom of the anode to increase the intensity of light in a specific wavelength range generated from the organic light-emitting layer to increase the intensity of light in a specific wavelength region generated from the organic light-emitting layer. A photonic crystal is transmitted to the anode, which is formed in the remaining area of a specific partial area at the bottom of the anode where the photonic crystal is formed, and is formed as an internal scattering structure film with a wrinkled structure to scatter light generated from the organic light-emitting layer to the substrate layer. An internal scattering layer for transmitting, a substrate layer formed at the bottom of the photonic crystal and the internal scattering layer to transmit light generated from the organic light-emitting layer to an external scattering layer, formed at the bottom of the substrate layer and dispersing a plurality of scattering particles. an external scattering layer that scatters light generated from the organic light-emitting layer and transmits it to the external quantum dot layer; and a plurality of quantum dots are formed at the bottom of the external scattering layer in a dispersed form to form the organic light-emitting layer. It includes an external quantum dot layer that emits external light by increasing the intensity of light generated from the inner scattering structure film, and the internal scattering structure film is formed by spin coating and curing a polymer composition on the top of the substrate layer to form ions (Ion). ) A transparent nano structure formed by etching to form a concavo-convex structure, and metal oxide deposited on the outside of the transparent nano structure by sputtering to change the concavo-convex structure of the transparent nano structure into a flat wrinkled structure. It includes a flattening member, wherein the refractive index of the flattening member is equal to or greater than the refractive index of the anode (Anode), and the external quantum dot layer is formed inside the external quantum dot layer to form the organic A raw light transmission end that transmits light generated in the light emitting layer to the outside without wavelength conversion, a red quantum dot end formed on one side of the external quantum dot layer that converts the light generated in the organic light emitting layer into light in the red wavelength region and transmits it to the outside, and It includes a green quantum dot end formed on the other side of the external quantum dot layer to convert light generated from the organic light-emitting layer into light in a green wavelength range and transmit it to the outside, and transmits the light generated from the organic light-emitting layer to the raw light transmission end and a red quantum dot end. And it is characterized by converting it into white light through a green quantum dot and emitting light to the outside.

Description

Organic light-emitting device including a photonic crystal for internal light extraction, an internal scattering layer, an external scattering layer, and an external quantum dot layer {OLED HAVING INTERNAL LIGHT EXTRACTING PHOTONIC CRYSTAL STRUCTURE, INTERNAL LIGHT SCATTERING LAYER, EXTERNAL LIGHT SCATTERING LAYER AND EXTERNAL QUANTUM DOT LAYER}

The present invention relates to OLED (Organic Light Emitting Diodes) products with increased internal light extraction efficiency.

OLED is receiving a lot of attention as a next-generation display device due to its low power consumption, high color reproduction, wide color gamut, fast response speed, and bendable characteristics. However, only about 20% of the light emitted from OLED can be extracted from the display device, which significantly reduces light extraction efficiency. The reason light extraction efficiency is low is because light is trapped at the interface between the transparent electrode (ITO) layer and the substrate and the interface between the substrate and air, which is due to differences in the refractive index of each material. A micro cavity structure is mainly applied to increase light transmission efficiency, but this structure has the problem of narrowing the viewing angle of the display panel due to differences in light extraction amount depending on the viewing angle of the display panel.

Republic of Korea Patent Publication No. 10-2020-0018954 (Name: Nanoparticles with adjustable refractive index, light scattering layer containing the same, and method for manufacturing the same, Publication date: 2020.02.21.) PCT Publication Patent No. WO2014-191733 (Name: Organic Light Emitting Diode Structure, Publication Date: 2014.04.12.)

The purpose of the present invention to solve the above problems is to manufacture an OLED device that increases light extraction efficiency from the OLED device and secures a wide viewing angle of the display panel.

The technical problems of the present invention are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below.

In order to achieve the above object, an organic light emitting device including a photonic crystal for internal light extraction, an internal scattering layer, an external scattering layer, and an external quantum dot layer according to an embodiment of the present invention receives electrons and holes and emits light of a specific wavelength. an organic light-emitting layer, a cathode formed at the top of the organic light-emitting layer to supply electrons to the organic light-emitting layer, and a cathode formed at the bottom of the organic light-emitting layer to supply holes to the organic light-emitting layer and transmit light generated from the organic light-emitting layer. An anode, a photonic crystal formed in a specific region at the bottom of the anode to increase the intensity of light in a specific wavelength region generated in the organic light-emitting layer and transmit it to the substrate layer, and a photonic crystal at the bottom of the anode. An internal scattering layer is formed in the remaining area of the specific partial area where the photonic crystal is formed and is formed as a wrinkle-structured internal scattering structure film to scatter light generated from the organic light-emitting layer and transmit it to the substrate layer, the photonic crystal and the internal scattering layer A substrate layer formed at the bottom and transmitting light generated from the organic light-emitting layer to an external scattering layer, formed at the bottom of the substrate layer and provided with a plurality of scattering particles in a dispersed form to scatter light generated from the organic light-emitting layer to an external scattering layer. An external scattering layer transmitted to the quantum dot layer and an external quantum dot formed at the bottom of the external scattering layer and having a plurality of quantum dots in a dispersed form to increase the intensity of light generated from the organic light-emitting layer and emit light to the outside. It includes a layer, and the internal scattering structure film is a transparent nanostructure formed by spin coating and curing a polymer composition on the top of the substrate layer and then etching it using an ion etching method to form a concavo-convex structure. Nano) structure and a flattening member in which the uneven structure of the transparent nano structure is changed into a flat wrinkled structure by depositing metal oxide on the outside of the transparent nano structure by sputtering, and the refractive index of the flattening member is, The refractive index of the anode is equal to or greater than that of the anode, and the external quantum dot layer is formed inside the external quantum dot layer to transmit the light generated from the organic light-emitting layer to the outside without wavelength conversion. A transmission end, a red quantum dot end formed on one side of the external quantum dot layer to convert light generated from the organic light-emitting layer into light in the red wavelength region and transmitted to the outside, and a red quantum dot end formed on the other side of the external quantum dot layer to transmit light generated from the organic light-emitting layer It includes a green quantum dot that converts light in the green wavelength range and transmits it to the outside, and converts the light generated in the organic light-emitting layer into white light through the raw light transmission end, red quantum dot, and green quantum dot to emit light to the outside. It is characterized by

In addition, a wrinkle structure having the same shape as the wrinkle structure of the internal scattering structure film according to the present invention is formed by transferring to the interface between the organic light-emitting layer and the anode and the interface between the organic light-emitting layer and the cathode.

In addition, the polymer composition according to the present invention includes polymethylmethacrylate (PMMA), and the metal oxide includes ZnO.

Internal light extraction efficiency can be improved by using an organic light-emitting device including a photonic crystal for internal light extraction, an internal scattering layer, an external scattering layer, and an external quantum dot layer, and a photonic crystal for internal light extraction, and an internal scattering layer formed with a nano-scattering structure. By applying , the effect of improving internal light extraction efficiency can be obtained. In addition, by converting the blue light generated from the organic light-emitting layer into red light and green light through the external quantum dot layer, white light can be generated throughout the organic light-emitting device, so white light is also required for organic light-emitting devices that only increase the intensity of light of a specific wavelength through photonic crystals. It can be used in lighting fixtures.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

Figure 1 is a diagram schematically showing the configuration of an organic light-emitting device including a photonic crystal for internal light extraction and an internal scattering layer according to an embodiment of the present invention.
Figure 2 is a diagram showing the shape of a transparent nanostructure among the components of an internal scattering structure film according to an embodiment of the present invention.
Figure 3 is a diagram showing the shape of a planarization member deposited on the outside of a transparent nanostructure among the components of an internal scattering structure film according to an embodiment of the present invention.
Figure 4 is a diagram schematically showing the structure of a photonic crystal according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily practice the present invention.

In describing the embodiments, descriptions of technical content that is well known in the technical field to which the present invention belongs and that are not directly related to the present invention will be omitted. This is to convey the gist of the present invention more clearly without obscuring it by omitting unnecessary explanation.

For the same reason, some components are exaggerated, omitted, or schematically shown in the accompanying drawings. Additionally, the size of each component does not entirely reflect its actual size. In each drawing, identical or corresponding components are assigned the same reference numbers.

Figure 1 is a diagram schematically showing the configuration of an organic light-emitting device including a photonic crystal for internal light extraction and an internal scattering layer according to an embodiment of the present invention.

Referring to FIG. 1, an organic light emitting device 10 including a photonic crystal for internal light extraction, an internal scattering layer, and an external quantum dot layer according to an embodiment of the present invention receives electrons and holes to generate light of a specific wavelength. An organic light-emitting layer 100, a cathode 200 formed at the top of the organic light-emitting layer 100 to supply electrons to the organic light-emitting layer 200, and a cathode 200 formed at the bottom of the organic light-emitting layer 100 to supply electrons to the organic light-emitting layer 100. An anode 300 that supplies holes and transmits light generated in the organic light-emitting layer 100, is formed in a specific partial area at the bottom of the anode 300, and transmits light generated in the organic light-emitting layer 100. Photonic crystal 400, which increases the intensity of light in the wavelength range and transmits it to the substrate layer 600, is formed in the remaining area of the specific partial area where the photonic crystal 400 is formed at the bottom of the anode 300. The internal scattering layer 500, which is formed of an internal scattering structure film 510 with a wrinkled structure, scatters light generated from the organic light-emitting layer 100 and transmits it to the substrate layer 600, the photonic crystal 400, and internal scattering. A substrate layer 600 formed at the bottom of the layer 500 and transmitting light generated from the organic light-emitting layer 100 to the external scattering layer 700, and a plurality of scattering particles formed at the bottom of the substrate layer 600. (710) is provided in a dispersed form to scatter the light generated from the organic light-emitting layer 100 and transmit it to the external quantum dot layer 800, and is formed at the bottom of the external scattering layer 700, It may include an external quantum dot layer 800 that has a plurality of quantum dots 810 in a dispersed form and emits light to the outside by increasing the intensity of light generated from the organic light emitting layer 100.

According to one embodiment of the present invention, the photonic crystal 400 may be formed of a photonic crystal selected from the group consisting of one-dimensional photonic crystal, two-dimensional photonic crystal, three-dimensional photonic crystal, and a mixture thereof.

According to one embodiment of the present invention, the external quantum dot layer 800 is formed inside the external quantum dot layer 800 and transmits the light generated in the organic light-emitting layer 100 to the outside without wavelength conversion. (820), a red quantum dot end 830 formed on one side of the external quantum dot layer 800 to convert the light generated in the organic light-emitting layer 100 into light in the red wavelength region and transmit it to the outside, and the external quantum dot layer ( 800) and includes a green quantum dot terminal 850 that is formed on the other side of the organic light-emitting layer 100 to convert light generated in the organic light-emitting layer 100 into light in a green wavelength range and transmit it to the outside, and transmits the light generated in the organic light-emitting layer 100 to the raw light. It can be converted into white light and emitted to the outside through the stage 820, the red quantum dot stage 830, and the green quantum dot stage 850.

According to one embodiment of the present invention, the red quantum dot terminal 830 is provided with a plurality of red quantum dot bodies 840 in a dispersed form to convert light generated from the organic light-emitting layer 100 into light in the red wavelength range. there is.

According to one embodiment of the present invention, the green quantum dot terminal 850 is provided with a plurality of green quantum dot bodies 860 in a dispersed form to convert light generated from the organic light-emitting layer 100 into light in the green wavelength range. there is.

According to one embodiment of the present invention, the plurality of scattering particles 520 may be formed of particles selected from the group consisting of silicon-based, polymer-based, metal oxide-based, and mixtures thereof.

Figure 2 is a diagram showing the shape of a transparent nanostructure among the components of an internal scattering structure film according to an embodiment of the present invention.

Referring to FIG. 2, the internal scattering structure film 510 is formed by spin coating and curing a polymer composition on the top of the substrate layer 600 and then etching it using an ion etching method to form irregularities. It may include a transparent nano structure 511 formed.

According to one embodiment of the present invention, the polymer composition (not shown) may include polymethylmethacrylate (PMMA).

According to one embodiment of the present invention, the height of the transparent nanostructure 511 may vary depending on the spin coating speed of the polymer composition. Figure 2(a) shows the spin coating speed at 1500 rpm, Figure 2(b) shows the spin coating speed at 1750 rpm, Figure 2(c) shows the spin coating speed at 2000 rpm, and Figure 2(d) shows the spin coating speed at 1750 rpm. This may be the shape of the transparent nanostructure 511 when the coating speed is applied at 2500 rpm. The higher the spin coating speed, the lower the height of the wrinkle structure can be.

Figure 3 is a diagram showing the shape of a planarization member deposited on the outside of a transparent nanostructure among the components of an internal scattering structure film according to an embodiment of the present invention.

Referring to FIG. 3, it includes a flattening member 512 that changes the uneven structure of the transparent nanostructure 511 into a flat wrinkled structure by depositing metal oxide on the outside of the transparent nanostructure 511 by sputtering. can do.

According to one embodiment of the present invention, the refractive index of the flattening member 512 may be equal to or greater than the refractive index of the anode.

According to one embodiment of the present invention, the metal oxide may include ZnO.

According to one embodiment of the present invention, a wrinkled structure having the same shape as the wrinkled structure of the internal scattering structure film 510 is formed at the interface between the organic light-emitting layer 100 and the anode 300 and the organic light-emitting layer 100. It may be formed at the interface of the cathode (200).

After forming the transparent nanostructure 511 into a concavo-convex shape, the flattening member 512 is deposited on the outside of the transparent nanostructure 511 to immediately form the anode (300) without changing the concavo-convex shape into a wrinkled structure. ) is formed, the uneven shape is transferred to the anode (300) and current is concentrated on the protruding part of the anode (300), which may cause leakage current or deteriorate electrical characteristics. there is.

The refractive index of the flattening member 512 may be the same as or greater than the refractive index of the anode 300. If the refractive index of the planarization member 512 is smaller than the refractive index of the anode 300, an additional waveguide mode in which light is reflected at the interface between the anode 300 and the planarization member 512. This is because it can be formed.

If the planarization member 512 is formed thick, light absorption may occur due to the planarization member 512, so the planarization member 512 can be formed as thin as possible. According to one embodiment of the present invention, the planarization member may be deposited to a thickness of 400 nm.

According to one embodiment of the present invention, the height of the wrinkle shape may also vary depending on the height of the transparent nanostructure 511. Figure 3(a) shows the spin coating speed at 1500 rpm, Figure 3(b) shows the spin coating speed at 1750 rpm, Figure 3(c) shows the spin coating speed at 2000 rpm, and Figure 3(d) shows the spin coating speed at 1750 rpm. The flattening member 512 may be deposited on the outside of the transparent nanostructure 511 formed by applying a coating speed of 2500 rpm.

Figure 4 is a diagram schematically showing the structure of a photonic crystal according to an embodiment of the present invention.

According to an embodiment of the present invention with reference to FIG. 4, the photonic crystal 400 may be an optical structure that causes a resonance phenomenon with respect to light in the visible light region and consequently improves light extraction efficiency. The height and pitch of the photonic crystal 400 may be equal to or greater than 300 nm and equal to or smaller than 700 nm. The photonic crystal 400 may require a planarization layer above a certain thickness.

The aperture ratio (fill factor) of the photonic crystal 400 can be variously adjusted (e.g., 5 to 95%) depending on the material, optical properties (refractive index, etc.) and device structure. The photonic crystal 400 may be formed in a shape such as a hole or a pillar. Additionally, the photonic crystal 400 may be arranged in a rectangular or hexagonal shape.

Internal light extraction efficiency can be improved by using an organic light-emitting device including a photonic crystal for internal light extraction, an internal scattering layer, an external scattering layer, and an external quantum dot layer, and a photonic crystal for internal light extraction, and an internal scattering layer formed with a nano-scattering structure. By applying , the effect of improving internal light extraction efficiency can be obtained. In addition, by converting the blue light generated from the organic light-emitting layer into red light and green light through the external quantum dot layer, white light can be generated throughout the organic light-emitting device, so white light is also required for organic light-emitting devices that only increase the intensity of light of a specific wavelength through photonic crystals. It can be used in lighting fixtures.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

100: organic light emitting layer
200: Cathode
300: Anode
400: Photonic crystal
500: internal scattering layer
510: Internal scattering structure film 511: Transparent nanostructure
512: Flattening member
600: substrate layer
700: external scattering layer
710: scattering particle body
800: External quantum dot layer
810: Quantum dot body 820: Raw light transmission end
830: Red quantum dot terminal 840: Red quantum dot body
850: green quantum dot terminal 860: green quantum dot body
10: Organic light emitting device

Claims (3)

An organic light-emitting layer that receives electrons and holes to generate light of a specific wavelength;
A cathode formed on top of the organic light-emitting layer to supply electrons to the organic light-emitting layer;
An anode formed at the bottom of the organic light-emitting layer to supply holes to the organic light-emitting layer and transmit light generated from the organic light-emitting layer;
a photonic crystal formed in a specific region at the bottom of the anode to increase the intensity of light in a specific wavelength region generated in the organic light-emitting layer and transmit it to the substrate layer;
An internal scattering layer formed in the remaining area of the specific partial area at the bottom of the anode where the photonic crystal is formed and formed as a wrinkled internal scattering structure film to scatter light generated from the organic light emitting layer and transmit it to the substrate layer;
A substrate layer formed at the bottom of the photonic crystal and the internal scattering layer to transmit light generated from the organic light emitting layer to the external scattering layer;
an external scattering layer formed at the bottom of the substrate layer and having a plurality of scattering particles in a dispersed form to scatter light generated in the organic light-emitting layer and transmit it to an external quantum dot layer; and
An external quantum dot layer is formed at the bottom of the external scattering layer and has a plurality of quantum dots in a dispersed form to increase the intensity of light generated from the organic light-emitting layer and emit light to the outside.
The internal scattering structure film is,
A transparent nano structure formed by spin coating and curing a polymer composition on the top of the substrate layer and then etching it using an ion etching method to form a concavo-convex structure; and
It includes a flattening member that changes the uneven structure of the transparent nanostructure into a flat wrinkled structure by depositing metal oxide on the outside of the transparent nanostructure by sputtering,
The refractive index of the flattening member is,
The refractive index of the anode is equal to or greater than the refractive index of the anode,
The external quantum dot layer is,
A raw light transmission stage formed inside the external quantum dot layer to transmit light generated from the organic light-emitting layer to the outside without wavelength conversion;
Red quantum dots formed on one side of the external quantum dot layer to convert light generated from the organic light-emitting layer into light in a red wavelength region and transmit it to the outside; and
It includes a green quantum dot layer formed on the other side of the external quantum dot layer to convert light generated from the organic light-emitting layer into light in a green wavelength range and transmit it to the outside,
An organic light-emitting device comprising a photonic crystal for internal light extraction and an internal scattering layer, wherein the light generated in the organic light-emitting layer is converted into white light through the raw light transmission end, the red quantum dot end, and the green quantum dot end to emit light to the outside. According to paragraph 1,
A photonic crystal for extracting internal light, and an interior, wherein a wrinkled structure having the same shape as the wrinkled structure of the internal scattering structure film is formed by transferring it to the interface between the organic light-emitting layer and the anode and the interface between the organic light-emitting layer and the cathode. An organic light emitting device including a scattering layer. According to paragraph 1,
The polymer composition is,
Contains polymethylmethacrylate (PMMA),
The metal oxide is,
An organic light-emitting device comprising a photonic crystal for internal light extraction and an internal scattering layer comprising ZnO.

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