KR20160141061A - Light extraction structure - Google Patents

Light extraction structure Download PDF

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Publication number
KR20160141061A
KR20160141061A KR1020150074220A KR20150074220A KR20160141061A KR 20160141061 A KR20160141061 A KR 20160141061A KR 1020150074220 A KR1020150074220 A KR 1020150074220A KR 20150074220 A KR20150074220 A KR 20150074220A KR 20160141061 A KR20160141061 A KR 20160141061A
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KR
South Korea
Prior art keywords
light
light extracting
substrate
present
extractors
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KR1020150074220A
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Korean (ko)
Inventor
이종희
문제현
박승구
성우진
이정익
조남성
주철웅
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한국전자통신연구원
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Priority to KR1020150074220A priority Critical patent/KR20160141061A/en
Publication of KR20160141061A publication Critical patent/KR20160141061A/en

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    • H01L51/5262—
    • H01L51/5275—
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/10—Details of semiconductor or other solid state devices to be connected
    • H01L2924/11—Device type
    • H01L2924/12—Passive devices, e.g. 2 terminal devices
    • H01L2924/1204—Optical Diode
    • H01L2924/12044—OLED

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Abstract

The light extractor comprises a substrate, first light extractors provided on the substrate and spaced apart from each other, and
And second light extractors on the substrate between the first light extractors, wherein the width and height of the second light extractors are smaller than those of the first light extractors.

Description

[0001] LIGHT EXTRACTION STRUCTURE [0002]

The present invention relates to a light extracting body, and more particularly to a light extracting layer having high density.

Recently, as the environmental problems have come to the fore, technologies using organic light emitting devices (OLEDs) that do not use heavy metals such as mercury and lead as a light source are attracting interest as environmentally friendly next generation lights. An organic light emitting device is an organic light emitting device that electrically excites an organic light emitting material to emit light. The organic light emitting device includes a substrate, an anode, a cathode, and an organic light emitting layer. Organic light emitting devices have excellent display characteristics such as wide viewing angle, fast response speed, thin thickness, low manufacturing cost, and high contrast. As the technology of the organic light emitting device develops, the internal quantum efficiency of the light source is improved. However, the organic light emitting device has a problem that only about 25% of the total light emission amount is emitted to the outside of the device, and the remaining 75% is isolated inside the organic light emitting device.

This is because when the light emitted from the organic light emitting layer passes through the interface between the layers having different refractive indexes, the refractive index of the material of the glass and plastic used as the substrate is lower than that of the organic light emitting layer and the anode or the cathode, It is known that the external luminous efficiency is not more than 25% because it is not released to the outside of the substrate due to total reflection and is caught inside each layer. The light that is trapped in each layer in the organic light emitting diode and is guided in the layer is referred to as a guided mode light and the light that is emitted to the outside air through the interface of each layer is referred to as emission mode light. The conversion of the waveguide mode light into the emission mode light and output to the outside of the device is referred to as light extraction.

A problem to be solved by the present invention is to provide a light extracting body having high density.

However, the problems to be solved by the present invention are not limited to the above-mentioned problems.

According to an aspect of the present invention, there is provided a light extracting body comprising: a substrate; first light extracting portions provided on the substrate and spaced apart from each other; And second light extractors on the substrate between the first light extractors, wherein the width and height of the second light extractors may be less than the first light extractors.

According to the present invention, the density of the light extracting body can be improved.

According to the present invention, a light extracting body having high light extraction efficiency can be formed.

According to the present invention, the light extraction efficiency of the microlens array can be improved.

However, the effect of the present invention is not limited to the above disclosure.

1 is a plan view of a substrate and a first light extracting portion of a light extracting body according to an embodiment of the present invention.
2 is a cross-sectional view of a light extracting body according to an embodiment of the present invention, which corresponds to line I-I 'in Fig.
3 is a process flow diagram illustrating a method of manufacturing an optical extractant according to an embodiment of the present invention.
FIGS. 4 and 5 are cross-sectional views for explaining a method of manufacturing the light extracting body according to an embodiment of the present invention, and correspond to the line I-I 'of FIG.
6 is a cross-sectional view of an optical extractant according to another embodiment of the present invention.
7 and 8 are SEM (scanning electron microscope) images of the light extracting body including the substrate and the first light extracting portion.
9 and 10 are SEM images of an optical extractant according to an embodiment of the present invention.
11 and 12 are SEM images of the light extracting body according to another embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features, and advantages of the present invention will become more readily apparent from the following description of preferred embodiments with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that the disclosure can be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

In this specification, when it is mentioned that a film (or layer) is on another film (or layer) or substrate, it may be formed directly on another film (or layer) or substrate, or a third film (Or layer) may be interposed. In the drawings, the sizes and thicknesses of the structures and the like are exaggerated for the sake of clarity. It should also be understood that although the terms first, second, third, etc. have been used in various embodiments herein to describe various orientations, films (or layers), etc., It should not be limited by the same terms. Each embodiment described and exemplified herein also includes its complementary embodiment. The expression " and / or " is used herein to mean including at least one of the elements listed before and after. Like numbers refer to like elements throughout the specification.

1 is a plan view of a substrate and a first light extracting portion of a light extracting body according to an embodiment of the present invention.

2 is a cross-sectional view of a light extracting body according to an embodiment of the present invention, which corresponds to line I-I 'in Fig.

1 and 2, a substrate 10 may be provided. The substrate 10 may support the first light extractors 20 and the second light extractors 32. The substrate 10 may be a plastic substrate or a glass substrate.

The first light extractors 20 may be provided on the substrate 10. From a plan viewpoint, the first light extractors 20 may be spaced apart from each other. The first light extracting units 20 can be convex upward in a direction perpendicular to the upper surface of the substrate 10. [ The first light extractors 20 are shown in a hemispherical shape, but are not limited thereto. The width of the first light extractors 20 may be several hundred nanometers to several hundred micrometers. The height of the first light extractors 20 may be from several tens of micrometers to about 300 micrometers.

The material of the first light extracting units 20 may be selected from the group consisting of polymethylmethacrylate (PMMA), urea resin powder, poly condensed plastic powder, PS (polystyrene), polyacrylonitrile (PAN) Polybutyl methacrylate (PBMA), but is not limited thereto. In one example, the first light extractors 20 may be a micro lens array (MLA).

The second light extractors 32 may be provided on the substrate 10 between the first light extractors 20. The upper surface of the second light extracting portions 32 may be a corrugated structure. The corrugated structure may have concave portions and convex portions in a direction perpendicular to the upper surface of the substrate 10. The wrinkle structure may be irregular. The irregularity may mean that the level of at least some of the valleys or troughs is different and that the height of at least some of the peaks or crests of the convexes may be different. From a planar viewpoint, the pleats may be areas surrounded by valleys or troughs. The wrinkles can extend in an unspecified direction. That is, the wrinkles may extend mainly in a curved shape. 9 to 12, which will be described later, the meaning of irregular wrinkles may become clearer. The second light extracting units 32 may be lower in height than the first light extracting units 20. In one example, the height of the second light extractors 32 may be from a few hundred nanometers to about 10 micrometers. The second light extracting portions 32 may be formed on the substrate 10 between the first light extracting portions 20 so that a light extracting body having a density of almost 100% can be provided. The higher the density, the higher the light extraction efficiency. Therefore, the light extracting body according to the present invention can improve the light extraction efficiency.

Hereinafter, a method for producing the light extracting body according to the present invention will be described.

3 is a process flow diagram illustrating a method of manufacturing an optical extractant according to an embodiment of the present invention.

FIGS. 4 and 5 are cross-sectional views for explaining a method of manufacturing the light extracting body according to an embodiment of the present invention, and correspond to the line I-I 'of FIG.

Referring to FIGS. 3 and 4, the first light extractors 20 may be formed on the substrate 10 (S10). In one example, the first light extractor 20 may be formed by an imprinting process. The material of the first light extracting units 20 may be selected from the group consisting of polymethylmethacrylate (PMMA), urea resin powder, poly condensed plastic powder, PS (polystyrene), polyacrylonitrile (PAN) Polybutyl methacrylate (PBMA), but is not limited thereto.

3 and 5, a composition layer 30 may be formed on the substrate 10 to form the second light extractor 32 (S20). The process of forming the composition layer 30 may be a coating process. For example, the coating process of the composition layer 30 may be a spin coating or a doctor knife process. Before the composition layer 30 is coated, impurities in the composition can be removed using a filter.

The composition may comprise a compound of formula (1).

Figure pat00001

In Formula 1, X is hydrogen and a halogen element, A is a crosslinking group, and Y1 to Y18 are each -, -O-, -S-, -COO-, -CO-, COS-, -SO2-, -CONH -, and -NH-, Zn, n + 1 is a repeating number of aliphatic or aromatic groups between Yn and Yn + 1 groups, and n is 1, 2, 3, 4, 5, Zn, n + 1 is 0 to 100 when n = 2, 3, 4, 7, 8, 11, 12, 15 and 16, Zn, n + 1 is 0 or 1, p is an integer of 1 to 10,000, and Zn and n + 1 are 0, Yn + 1, and Zn + 1 when n = 1, 5, 9, 13, Is -.

Here Yn or Yn + 1 - means to connect. For example, in R 1 R 2 -Yn-Yn is - if is the same as R 1 -R 2.

The crosslinking group may have at least one structure selected from structures represented by the following formula (2).

Figure pat00002

In a specific example, x is hydrogen or fluorine and A is

Figure pat00003
. ≪ / RTI >

Preferably, the compound of formula (1) may be any one selected from the following formula (3).

Figure pat00004

Figure pat00005

Figure pat00006

In formula (3), q may be an integer of 0 to 10000.

The compound of formula (I) may be a liquid having a viscosity of 0 to 50 and 1 to 10 7 .

In one example, the compound of Formula 1 may be a liquid prepolymer. The compound may have two or more crosslinking groups at both ends. The compound may be capable of forming a film that is polymerized after the curing process. Through the curing process, the compounds can be chemically bonded freely in three dimensions and at the same time can be phase-changed from a liquid phase to a solid phase. The volume of the compound can be shrunk. Thus, a film having a surface structure of irregular wrinkles can be formed without any additional process. That is, the surface structure of irregular wrinkles can be formed spontaneously. Wrinkles on the surface can increase the light extraction effect. Specifically, such a film has various functions such as an external light extraction function, an internal light extraction function, an optical antireflection function, a display pixel light extraction function, a low reflection function, a flexible light extraction function and a water repellent film coating function, have.

The composition may further comprise a curing initiator. Through the curing initiator, the compound of formula (1) can be cured. The curing initiator is preferably contained in an amount of 0.1 to 10 wt.%, More preferably 0.5 to 2.5 wt.%, Based on the total weight of the weight of the compound and the weight of the curing initiator. The curing initiator may be a photocuring initiator or a thermosetting initiator.

The composition may further comprise polymeric monomers. The polymerizable monomer may be a low molecular weight vinyl monomer and acts as a chain extender to further increase the molecular weight after crosslinking of the prepolymer. The polymerizable monomer may be included in an amount of 0.1 to 50 wt.% Based on the total weight of the composition. The polymerizable monomer may be 2,3,4,5,6-pentafluoro styrene, divinyl benzene, methyl methacrylate, methyl acrylate, tri Trifluoroacetic acid allyl ester, trifluoroacetic acid vinyl ester, 2,2,2-trifluoroethyl methacrylate, 1,1,1-trichloroacetic acid, 3,3,3-hexafluoroisopropyl ester, 3,3,3-hexafluoroisopropyl ester, 1,1,1,3,3,3-hexafluoro methacrylate, Methacrylic acid 1,1,1,3,3,3-hexafluoroisopropyl ester, 1-pentafluorophenyl-pyrrole-2,5-dione, N-methyl maleimide, N-ethyl maleimide, N-propyl maleimide, N-butyl maleimide, N-methylmaleimide, - Tasheri - Butyl Male Mid (N- tert -butyl maleimide), N - pentyl maleimide (N-pentyl maleimide), and N - cyclohexyl maleimide at least one selected from the group comprising the (N-hexyl maleimide) may be.

The composition may further comprise a solvent to dilute the compound, and the solvent may be included in an amount of 1 to 99 wt.% Based on the total weight of the composition. The solvent may be selected from the group consisting of cyclopentanone, cyclohexanone, gamma-butyrolactone, toluene, methanol, ethanol, ethyl ether, N, N-dimethyl acetamide , N-methyl pyrrolidinone, tetrahydrofuran, ethyl acetate, and hexane. The reaction may be carried out in the presence of at least one solvent selected from the group consisting of N-methyl pyrrolidinone, N-methyl pyrrolidinone, tetrahydrofuran, ethyl acetate and hexane. The viscosity and refractive index of the composition can be easily varied depending on the mixing ratio of the compound and the polymerizable monomer and / or solvent.

Referring again to FIGS. 2 and 3, the composition layer 30 may be cured to form a second light extracting portion 32 having a surface structure of irregular wrinkles (S30). In one example, the composition layer 30 may be photocurable. For example, ultraviolet light (UV) may be applied to the composition layer 30 to allow the composition layer 30 to cure. In this case, the composition layer 30 may contain a photocuring initiator. The step of irradiating ultraviolet rays may be conducted for 1 to 30 minutes under an atmosphere of an inert gas (for example, nitrogen gas (N 2 )) or in a vacuum state. After the ultraviolet light is irradiated, the cured composition layer 30 may be heat treated at about 100 to 300 占 폚. The heat treatment may be conducted under an atmosphere of an inert gas (for example, nitrogen gas (N 2 )) or in a vacuum state.

In another example, the composition layer 30 may be thermally cured. For example, the composition layer 30 can be thermally cured at a temperature of about 50-100 < 0 > C to be thermally cured. In this case, the composition layer 30 may comprise a thermoset initiator. The heat treatment can be carried out in an inert gas (for example, nitrogen gas (N 2 )) atmosphere or under vacuum for 5 minutes or more. Preferably, the composition layer 30 can be heat treated at a temperature of about 100 to 300 DEG C for 0.5 to 2 hours.

In another example, the composition layer 30 can be cured without a curing agent. For example, the composition layer 30 can be placed in air, an inert gas (e.g., nitrogen gas (N 2 )) atmosphere, or under vacuum for a period of at least about 5 minutes and at least about 200 ° C.

Through the curing process, the compound of Formula 1 contained in the composition layer 30 can be three-dimensionally crosslinked. Thus, the second light extracting portion 32 having a surface structure of irregular wrinkles can be formed. The irregular surface of the corrugation may include concave and convex portions in a direction perpendicular to the top surface of the substrate 10. The refractive index of the second light extracting portion 32 may be N1. The refractive index N1 may be about 1.4 to 1.8. If the surface of the second light extracting portion 32 has an irregular wrinkle structure, extraction dependence on the specific wavelength of the second light extracting portion 32 can be removed. The extraction dependency for a specific wavelength means that mainly only a specific wavelength is optically extracted. The second light extracting portion 32 including the surface structure of irregular wrinkles may have a light extracting effect for various wavelengths.

Through the above process, the fill-factor of the optical extractant can be improved. When the density of the light extracting body is high, the light extracting performance can be excellent. For example, the present invention can be applied to a microlens array (MLA). The second light extractors 32 are provided between the microlenses, and the density can reach almost 100%. Thus, the light extraction efficiency of the microlens array MLA can be improved.

6 is a cross-sectional view of an optical extractant according to another embodiment of the present invention. For the sake of simplicity of explanation, a description of substantially the same portions as those of the method of manufacturing the light extracting body described with reference to Figs. 3 to 5 is omitted.

Referring to FIG. 6, the third light extracting units 34 may be formed on the upper surface of the first light extracting units 20. The third light extracting portions 34 may include the same material as the second light extracting portions 32. The third light extracting units 34 may be formed in the same manufacturing process as the second light extracting units 32. For example, when the composition of FIG. 5 is coated to the top surface of the first light extracting portions 20, the third light extracting portions 34 may be formed on the top surface of the first light extracting portions 20. The light totally reflected in the first light extracting units 20 can be extracted through the third light extracting units 34 on the upper surface of the first light extracting units 20. [ That is, the light extraction efficiency can be further improved through the third light extracting units 34 on the upper surface of the first light extracting units 20.

Hereinafter, an optical extractant according to embodiments of the present invention will be described with reference to an SEM image. For the sake of explanation, the same reference numerals as those used in Figs. 1 to 6 are used.

7 and 8 are SEM (scanning electron microscope) images of the light extracting body including the substrate and the first light extracting portion.

Referring to Figs. 7 and 8, in a plan view, the circular structure is the first light extracting section 20. Fig. The area between the first light extractors 20 is the upper surface of the substrate 10. The diameter of the first light extracting portion 20 is about 80 micrometers.

9 and 10 are SEM (scanning electron microscope) images of the light extracting body according to an embodiment of the present invention.

Referring to FIGS. 9 and 10, second light extracting portions 32 having an irregular wrinkle structure are formed between the first light extracting portions 20. The dark portions of the second light extracting portions 32 are concave portions, and the bright portions correspond to the convex portions. Since the light extracting body of this embodiment has a higher density than the light extracting body described with reference to Figs. 7 and 8, the light extracting efficiency can be improved.

11 and 12 are SEM (scanning electron microscope) images of the light extracting body according to another embodiment of the present invention.

Referring to FIGS. 11 and 12, the third light extracting portions 34 may be formed on the upper surface of the first light extracting portions 20 of the light extracting body described with reference to FIGS. The light extracting body of this embodiment can extract light totally reflected in the first light extracting section 20, so that light extraction efficiency can be improved.

The present invention has been described with reference to the preferred embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

10: substrate
20: First light extracting part
30: composition layer
32: second light extracting unit
34: Third light extracting unit

Claims (1)

Board;
First light extractors provided on the substrate and spaced apart from each other; And
And second light extractors on the substrate between the first light extractors,
Wherein the second light extractors are smaller in width and height than the first light extractors.
KR1020150074220A 2015-05-27 2015-05-27 Light extraction structure KR20160141061A (en)

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