KR20210091026A - Organic light emitting device including nano-structures and manufacturing method thereof - Google Patents

Abstract

The present invention relates to an organic light emitting device including nanostructures and a manufacturing method thereof. An organic light emitting device according to an embodiment includes a substrate including an epoxy layer having a nano-wrinkle pattern formed thereon, an organic light emitting layer formed on the substrate, and encapsulation glass formed to cover the organic light emitting layer on the substrate. It is possible to improve viewing angle dependence characteristics and color shift characteristics and prevent a black tint phenomenon.

Description

Organic light-emitting device including nano-structure and manufacturing method therefor {ORGANIC LIGHT EMITTING DEVICE INCLUDING NANO-STRUCTURES AND MANUFACTURING METHOD THEREOF}

The present invention relates to an organic light emitting device and a method for manufacturing the same, and more particularly, to a technical idea of an organic light emitting device including a nanostructure.

The external quantum efficiency of an organic light emitting diode is theoretically calculated as follows.

[Equation 1]

은 외부 양자 효율,

은 내부 양자 효율,

은 광추출 효율,

는 exciton의 생성량,

는 efficiency of radiative decay of excitons를 의미한다.here,

is the external quantum efficiency,

is the internal quantum efficiency,

Silver light extraction efficiency,

is the amount of exciton produced,

is the efficiency of radiative decay of excitons.

Based on Equation 1, in order to increase the external quantum efficiency coming out, the internal quantum efficiency must be high. In order to increase the internal quantum efficiency, the amount of exciton generation must be large, and for this purpose, an ideal charge balance must be obtained. In addition, if the charge balance is ideally matched, deterioration at the interface can be suppressed, which helps to improve the lifespan. For this reason, it is very important to balance the charge of the OLED and optimize the device.

In order to balance the charge of the OLED device, a recombination zone in which carriers injected from the electrode form excitons and recombine should be formed in the central portion of the emission layer (EML). At this time, the recombination zone is affected by electron and hole injection characteristics. Assuming that the energy barrier between the interfaces is ideal around 0.3 eV, the electron and hole injection characteristics show a difference according to the mobility of each material.

As described above, there are many reports that internal quantum efficiency can be obtained up to 100% when efficiency is maximized through thickness optimization to compensate for differences in mobility or implantation characteristics according to materials.

However, even in this case, it is difficult for the external quantum efficiency to exceed 20%, which means that as light exits the device, waveguide mode, substrate mode, surface plasmon polariton mode, and absorption This is because it is lost through a mode such as absorption. The amount of light lost through this is close to 80%, and to minimize this, various external light extraction techniques can be used. It is unfortunate that such technologies cannot be applied to display technology. The main reason is that it is difficult to overcome the pixel blur caused by the application of nano and micro structures.

Therefore, currently, many panel makers are maximizing their efficiency through a micro-cavity structure, which produces non-ideal devices with poor viewing angle characteristics.

In order to solve the problem of deterioration of viewing angle characteristics, it is necessary to consider the introduction of an omnidirectional scatterer, and reports have been published that actually introduced a nanoporous film to suppress the viewing angle dependence. However, when this technology is introduced, diffuse reflection occurs, which causes an incidental problem in which the black state, which is the function of the circularly polarizing film, is broken. A new technology for blocking black tint was needed.

Korean Patent No. 10-1973287, "Organic light emitting device having a hole transport layer including a composite" Korean Patent Application Laid-Open No. 10-2018-0132275, "Organic electroluminescent device including an interface protection layer (IPL)"

An object of the present invention is to provide an organic light emitting device capable of improving viewing angle dependence characteristics and color shift characteristics and blocking black tint phenomenon by including a nanostructure inside the device, and a method for manufacturing the same.

Another object of the present invention is to provide an organic light-emitting device capable of minimizing a decrease in current efficiency by including an epoxy filler inside the device, and a method for manufacturing the same.

An organic light emitting device according to an embodiment of the present invention includes a substrate including an epoxy layer having a nano-wrinkle pattern formed thereon, an organic light emitting layer formed on the substrate, and encapsulation glass formed to cover the organic light emitting layer on the substrate (encapsulation glass) may be included.

According to one side, the organic light emitting device may further include an epoxy filler formed between the organic light emitting layer and the encapsulation glass.

According to one side, the organic emission layer may be formed by stacking a first electrode, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, a second electrode, and a capping layer.

According to one side, the epoxy layer on which the nano-wrinkle pattern is formed is formed through a master mold having a nano-wrinkle structure, and the master mold includes a polymer layer and a metal layer formed on the polymer layer, wherein the metal layer is a polymer layer. It can be formed into a nano-wrinkled structure due to the difference in the coefficient of thermal expansion with

According to one side, in the epoxy layer on which the nano-wrinkle pattern is formed, the values of the pitch and the depth of the nano-wrinkle pattern may be determined according to the thickness of the metal layer.

A method of manufacturing an organic light emitting device according to an embodiment of the present invention comprises the steps of: forming a substrate including an epoxy layer on which a nano-wrinkle pattern is formed; forming an organic light emitting layer on the substrate; and forming an encapsulation glass to cover the organic light emitting layer, wherein the substrate may include an epoxy layer in which a nano-wrinkle pattern is formed on a surface adjacent to the organic light emitting layer.

According to one side, the method of manufacturing the organic light emitting device may further include forming an epoxy filler between the organic light emitting layer and the encapsulation glass.

According to one side, the step of forming the substrate includes the steps of manufacturing a master mold having a nano-wrinkle structure, applying an epoxy material on the master mold, and the master mold and the glass substrate coated with the epoxy material It may include forming an epoxy layer having a nano-wrinkle pattern formed thereon on a glass substrate through an imprinting process using a UV-curing step of the epoxy layer having a nano-wrinkle pattern formed thereon.

According to one side, the manufacturing of the master mold includes forming a polymer layer on a mold substrate, heat-treating the mold substrate on which the polymer layer is formed at a first temperature, and depositing a metal layer on the heat-treated polymer layer. and cooling the polymer layer on which the metal layer is deposited to a second temperature to form the metal layer in a nano-wrinkled structure.

According to one side, in the step of forming the metal layer into a nano-wrinkle structure, the metal layer may be formed into a nano-wrinkle structure due to a difference in coefficients of thermal expansion between the polymer layer and the metal layer.

According to one side, the depositing of the metal layer may control the thickness of the metal layer formed by deposition on the heat-treated polymer layer, thereby controlling the values of pitch and depth of the nano-wrinkle pattern.

According to one embodiment, the organic light emitting device of the present invention may include a nanostructure to improve viewing angle dependence characteristics and color shift characteristics, and block a black tint phenomenon.

According to an embodiment, the organic light emitting device of the present invention may include an epoxy filler to minimize a decrease in current efficiency.

1 is a view for explaining an organic light emitting diode according to an embodiment.
2 is a view for explaining an embodiment of an organic light emitting device according to an embodiment.
3 is a diagram for explaining an energy band diagram of an organic light emitting diode according to an exemplary embodiment.
4 is a view for explaining characteristics of a nano-wrinkle pattern of an organic light emitting diode according to an embodiment.
5A to 5H are diagrams for explaining characteristics of an organic light emitting diode according to an exemplary embodiment.
6 is a view for explaining a light scattering effect of an organic light emitting diode according to an exemplary embodiment.
7 is a view for explaining a blocking characteristic of a black tint phenomenon of an organic light emitting diode according to an exemplary embodiment.
8 is a view for explaining a method of manufacturing an organic light emitting device according to an exemplary embodiment.
9 is a view for explaining a method of manufacturing a substrate on which a nano-wrinkle pattern is formed according to an embodiment.
10 is a view for explaining a method of manufacturing a master mold according to an embodiment.

Specific structural or functional descriptions of the embodiments according to the concept of the present invention disclosed herein are only exemplified for the purpose of explaining the embodiments according to the concept of the present invention, and the embodiment according to the concept of the present invention These may be embodied in various forms and are not limited to the embodiments described herein.

Since the embodiments according to the concept of the present invention may have various changes and may have various forms, the embodiments will be illustrated in the drawings and described in detail herein. However, this is not intended to limit the embodiments according to the concept of the present invention to specific disclosed forms, and includes changes, equivalents, or substitutes included in the spirit and scope of the present invention.

Terms such as first or second may be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one element from another, for example, without departing from the scope of rights according to the inventive concept, a first element may be termed a second element, and similar The second component may also be referred to as the first component.

When a component is referred to as being “connected” or “connected” to another component, it is understood that the other component may be directly connected or connected to the other component, but other components may exist in between. it should be On the other hand, when it is mentioned that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in between. Expressions describing the relationship between elements, for example, “between” and “between” or “directly adjacent to”, etc. should be interpreted similarly.

The terminology used herein is used only to describe specific embodiments, and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In this specification, terms such as "comprise" or "have" are intended to designate that the described feature, number, step, operation, component, part, or combination thereof exists, and includes one or more other features or numbers, It should be understood that the possibility of the presence or addition of steps, operations, components, parts or combinations thereof is not precluded in advance.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present specification. does not

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, the scope of the patent application is not limited or limited by these examples. Like reference numerals in each figure indicate like elements.

1 is a view for explaining an organic light emitting diode according to an embodiment.

Referring to FIG. 1 , an organic light emitting diode 100 according to an embodiment includes a nano structure to improve viewing angle dependence and color shift characteristics, and to provide black tint. phenomenon can be blocked.

In addition, the organic light emitting diode 100 may include an epoxy filler to minimize a decrease in current efficiency.

To this end, the organic light emitting device 100 includes a substrate 110 having an epoxy layer on which a nano-wrinkle pattern is formed, and an organic light emitting layer 120 formed on the substrate 110 and the substrate 110 . An encapsulation glass 130 formed to cover the organic light emitting layer 120 may be included.

In addition, the organic light emitting device 100 may further include an epoxy filler 140 formed between the organic light emitting layer 120 and the encapsulation glass 130 .

That is, the organic light emitting device 100 may improve the viewing angle dependence characteristics and color shift characteristics by forming the nano-wrinkle pattern under the organic light emitting layer 120 .

In addition, the organic light emitting device 100 fills an air-gap provided between the organic light emitting layer 120 and the encapsulation glass 130 with the epoxy filler 140 , thereby generating a current due to the nano-wrinkle pattern. It is possible to minimize a decrease in efficiency, where the epoxy filler 140 may be an index-matched filler.

Specifically, the epoxy filler 140 may include a material having a refractive index matching at least one of the organic light emitting layer 120 and the encapsulation glass 130 .

As a more specific example, when the refractive index of the air-gap is nD ²² = 1, the refractive index of the organic material is nD ²² = 1.75, and the refractive index of the encapsulation glass is nD ²² = 1.5, as the epoxy filler 140 ^{As the epoxy material used, NOA 81 (Norland Products, Inc.) (refractive index nD 22} = 1.56) having a refractive index similar to that of the organic material and the encapsulation glass than that of the air-gap may be applied.

Through this, when the organic light emitting diode 100 is provided with only the nano-wrinkle pattern, the current efficiency decreases by about 30.8%, but by additionally including the epoxy filler 140, the decrease in current efficiency can be minimized to about 7.7%. .

For example, the organic emission layer 120 may be formed by stacking a first electrode, a hole injection layer, a hole transport layer, an emission layer, an electron transport layer, an electron injection layer, a second electrode, and a capping layer.

Preferably, the organic light emitting device 100 may be a top emission organic emitting diode (TEOLED).

According to one side, the epoxy layer on which the nano-wrinkle pattern provided on the substrate 110 is formed may be formed through a master mold having a nano-wrinkle structure.

In addition, the master mold includes a polymer layer and a metal layer formed on the polymer layer, but the metal layer may be formed in a nano-wrinkled structure due to a difference in coefficient of thermal expansion with the polymer layer.

For example, the polymer layer includes at least one of polydimethylsiloxane (PDMS), butadiene, and urethane, and the metal layer includes silver (Ag), aluminum (Al), and gold (Au). , Bismuth (Bi), Calcium (Ca), Cobalt (Co), Chromium (Cr), Copper (Cu), Iron (Fe), Gallium (Ga), Gadolinium (Gd), Hydrogen Fluoride (Hf), Indium (In) ), magnesium (Mg), manganese (Mn), molybdenum (Mo), niobium (Nb), neodymium (Nd), nickel (Ni), lead (Pb), palladium (Pd), platinum (Pt), sulfur (S), antimony (Sb), selenium (Se), silicon (Si), samarium (Sm), tin (Sn), tantalum (Ta) , at least one of tellurium (Te), titanium (Ti), tungsten (W), yttrium (Y), ytterbium (Yb), zinc (Zn), and zirconium (Zr).

Preferably, the polymer layer may be implemented as a polydimethylsiloxane (PDMS) film, and the metal layer may be implemented as an aluminum (Al) metal layer.

According to one side, in the epoxy layer on which the nano-wrinkle pattern is formed, the values of the pitch and the depth of the nano-wrinkle pattern may be determined according to the thickness of the metal layer.

In other words, in the master mold for forming the nano-wrinkle pattern, randomly distributed nano-wrinkle structures may be formed due to the difference in the coefficient of thermal expansion between the metal layer and the polymer layer, in which case the pitch and depth of the nano-wrinkle pattern (nano-wrinkle structure) The value of may be determined according to the thickness of the metal layer.

Preferably, the nano-wrinkle pattern has a pitch of 200 nm to 800 nm and a depth of 100 nm to 500 nm, so that it can be designed to cover the entire wavelength range (RGB, 400 nm to 700 nm) of the visible light region.

2 is a view for explaining an embodiment of an organic light emitting device according to an embodiment.

In other words, FIG. 2 is a diagram for explaining an example of the organic light emitting device according to the embodiment described with reference to FIG. 1 , and overlaps with the contents described with the organic light emitting device according to the embodiment among the contents described with reference to FIG. 2 . The description will be omitted.

Referring to FIG. 2 , the organic light emitting diode 200 according to an embodiment may include a substrate 210 , organic light emitting layers 221 to 228 , and encapsulation glass 230 .

According to one side, the substrate 210 may be formed with a glass substrate and an epoxy layer formed on the glass substrate, and the epoxy layer may have a nano-wrinkle pattern formed thereon.

In addition, an epoxy filler 240 may be provided between the organic emission layers 221 to 228 and the encapsulation glass 230 .

For example, the organic light emitting layers 221 to 228 and the epoxy filler 240 may be formed on the epoxy layer on which the nano-wrinkle pattern is formed ^{under high vacuum conditions (< 5x10 -7 Torr) through thermal evaporation.} .

In addition, the epoxy filler 240 may include the same epoxy material as the epoxy layer on which the nano-wrinkle pattern of the substrate 210 is formed, but is not limited thereto. Preferably, the epoxy filler 240 may include NOA 81 (Norland Products, Inc.) as an epoxy material.

According to one side, the organic light emitting layers 221 to 228 include a first electrode 221 , a hole injection layer 222 , a hole transport layer 223 , a light emitting layer 224 , an electron transport layer 225 , an electron injection layer 226 , The second electrode 227 and the capping layer 228 may be sequentially stacked.

For example, the first electrode 221 may be a highly reflective anode electrode, and the second electrode 227 may be a cathode electrode.

More specifically, the first electrode 221 is an electrode that provides holes to the emission layer, and may be formed of a transmissive electrode, a reflective electrode, or a stacked structure thereof.

Transparent and highly conductive indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO ₂ ), zinc oxide (ZnO), metal oxide/metal/metal oxide multilayer, graphene ( graphene), carbon nanotubes, and polyethylenedioxythiophene:polystyrenesulfonate (PEDOT:PSS).

Examples of reflective electrode materials include Ag/ITO, Ag/IZO, aluminum-lithium (Al-Li), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), aluminum/silver (Al/Ag), Lithium Fluoride/Aluminum (LiF/Al), Lithium (Li), Magnesium (Mg), Aluminum (Al), Aluminum-Lithium (Al-Li), Calcium (Ca), Magnesium-Indium (Mg-In), Magnesium -Silver (Mg-Ag), ytterbium (Yb), platinum (Pt), gold (Au), nickel (Ni), copper (Cu), barium (Ba), silver (Ag), silver nanowire (AgNWs), It may include at least one of indium (In), ruthenium (Ru), lead (Pd), rhodium (Rh), iridium (Ir), osmium (Os), calcium (Ca), and cesium (Cs).

Preferably, the first electrode 221 is a highly reflective electrode, and may be formed of a multilayer structure of aluminum/silver (Al/Ag).

The hole injection layer 222 formed on the first electrode 221 may serve to inject holes injected from the first electrode 221 into the emission layer 224 .

As the hole injection layer 222, a known material for the hole injection layer may be used. For example, the hole injection layer 222 may include PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate), NPB (N, N-bis-(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'diamine), TPD(N,N'-bis(3-methlyphenyl)-N,N'- diphenyl-[1,1'-biphenyl]-4,4'-diamine), TAPC(1,1-Bis[4-[N,N'-di(p-tolyl)amino]phenyl]cyclohexane), HMTPD ( (3-tolyl)amino]3,3'-dimethylbiphenyl), TCTA(Tris(4-carbazoyl-9-ylphenyl)amine), P3HT(Poly(3-hexylthiophene-2,5-diyl)), 2TNATA(4, 4',4'''-tris(N-(2-naphthyl)-N-phenyl-amino)-triphenylamine), m-MTDATA (4,4',4''-Tris[phenyl(m-tolyl)amino ]triphenylamine), DNTPD(N,N'-bis-[4-(di-m-tolylamino)phenyl]-N,N'-diphenylbiphenyl-4,4'-diamine), NPD(N,N'-bis( 1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine(α-NPD)), DPPD(N,N'-diphenyl-p-phenylenediamine), 4BTPD (2, 2'-bis(4-ditolylaminophenyl)-1,1'-biphenyl), 3BTPD (2,2'-bis(3-ditolylaminophenyl)-1,1'-biphenyl) and DTASi (bis[4-(p,p) It may include at least one selected from the group consisting of '-ditolylamino)-phenyl]diphenylsilane).

Preferably, the hole injection layer 222 may be formed using a spin coating method, and the coating conditions are a compound used as a material of the hole injection layer 222, a desired structure of the hole injection layer 120, and Although different depending on thermal properties, the coating speed of about 2000 rpm to 5000 rpm and the heat treatment temperature for solvent removal after coating may be appropriately selected in the temperature range of about 80° C. to 200° C.

That is, since the hole injection layer 222 is formed by a solution process, a large-area process is possible, the process time can be shortened, and restrictions on the semiconductor properties of the first electrode 221 and the second electrode 227 are reduced. can be reduced

The hole transport layer 223 serves to move holes injected from the first electrode to the emission layer, and VB-FNPD(9,9-Bis[4-[(4-ethenylphenyl)methoxy]phenyl]-N2, N7-di -1-naphthalenyl-N2,N7-diphenyl-9H-Fluorene-2,7-diamine), VNPB(N4,N4'-Di(naphthalen-1-yl)-N4,N4'-bis(4-vinylphenyl)biphenyl -4,4'-diamine), TFB(Poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl) diphenylamine)]), PTAA(Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]), Poly-TPD(Poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl) -benzidine]), Poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(N,N'-diphenyl)-N,N'-di(p-butylphenyl)-1,4-diamino- benzene)] end capped with dimethylphenyl, Poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(N,N' -bis{4-butylphenyl}-benzidine-N,N'-{1 ,4-diphenylene})], Poly[(9,9-dihexylfluorenyl-2,7-diyl)-alt-(N,N'bis{p-butylphenyl}-1,4-diaminophenylene)], Poly[(9 ,9-dioctylfluorenyl-2,7-diyl)-alt-(N,N'-bis{p-butylphenyl}-1,1'-biphenylene-4,4'-diamine)] and Poly[(9,9- at least one selected from the group consisting of dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(pbutylphenyl)) diphenylamine)] may include

Preferably, the hole transport layer 223 may include N0-bis(naphthalen-1-yl)-N or N0-bis(phenyl)benzidine (NPB).

In the light emitting layer 224, holes injected from the first electrode 221 and passed through the hole transport layer 223 and electrons injected from the second electrode 227 and passed through the electron transport layer 225 recombine to generate excitons, A layer that emits light while the generated excitons change from an excited state to a ground state, and may be composed of a single layer or a multilayer.

For example, the light emitting layer 224 may be manufactured by further adding a light emitting dopant to a host, and as a material of the fluorescent host, tris (8-hydroxy-quinolinato) aluminum (Alq3) ), 9,10-di (naphthi-2-yl) anthracene (AND), 3-Tert-butyl-9,10-di (naphthi-2-yl) anthracene (TBADN), 4,4'-bis (2 ,2-Diphenyl-ethen-1-yl)-4,4'-dimethylphenyl (DPVBi), 4,4'-bisBis(2,2-diphenyl-ethen-1-yl)-4,4' -Dimethylphenyl (p-DMDPVBi), Tert(9,9-diarylfluorene)s (TDAF), 2-(9,9'-spirobifluoren-2-yl)-9,9'-spirobi Fluorene (BSDF), 2,7-bis(9,9'-spirobifluoren-2-yl)-9,9'-spirobifluorene (TSDF), bis(9,9-diarylfluorene) )s (BDAF) and at least one of 4,4'-bis(2,2-diphenyl-ethen-1-yl)-4,4'-di-(tert-butyl)phenyl (p-TDPVBi) The phosphorescent host material may include 1,3-bis(carbazol-9-yl)benzene (mCP), 1,3,5-tris(carbazol-9-yl)benzene (tCP), 4,4',4"-lys(carbazol-9-yl)triphenylamine (TCTA), 4,4'-bis(carbazol-9-yl)biphenyl (CBP), 4,4'-bis Bis(9-carbazolyl)-2,2'-dimethyl-biphenyl (CBDP), 4,4'-bis(carbazol-9-yl)-9,9-dimethyl-fluorene (DMFL-CBP), 4,4'-bis(carbazol-9-yl)-9,9-bisbis(9-phenyl-9H-carbazole)fluorene (FL-4CBP), 4,4'-bis(carbazole-9 -yl)-9,9-di-tolyl-fluorene (DPFL-CBP) and 9,9-bis(9-phenyl-9H-carbazole) fluorene (FL-2CBP) may include at least one there is.

Preferably, the light emitting layer 224 includes beryllium bisbenzo[h]quinolin-10-olate (Bebq2) as a host material and bis[2,4-dimethyl-6-(4-methyl-2-quinolinyl-kN) as a dopant material. phenyl-kC] (2,2,6,6-tetramethyl-3,5-heptanedionato-kO3 (Ir(mphmq)2tmd).

The electron transport layer 225 may serve to move electrons injected from the second electrode 160 to the emission layer 140 , for example, the electron transport layer 225 may be TPBi(2,2′,2″- (1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole)), Alq3(Tris(8-hydroxyquinoline) Aluminum), PCBM(Phenyl-C61-butyric acid methyl ester), TAZ(3 -(4-biphenyl)-4-phenyl-5-(4-tertbutylphenyl)-1,2,4-triazole), BPhen(4,7-Diphenyl-1,10-phenanthroline), BAlq(Bis(8-hydroxy) -2-methylquinoline)-(4-phenylphenoxy)aluminum), TSPO1 (diphenylphosphine oxide-4-(triphenylsilyl)phenyl), B4PyMPM [bis-4,6-(3,5-di-4-pyridylphenyl)-2-methylpyrimidine ], TmPyPB (Two pyridine-containing triphenylbenzene derivatives of 1,3,5-tri(m-pyrid-3-yl-phenyl)benzene), 3TPYMB (tris-[3-(3-pyridyl)mesityl] borane), TpPyPB (1,3,5-tri(p-pyrid-3-yl-phenyl)benzene), TPPB (1,3,5-tris[3,5-bis(3-pyridinyl)phenyl]benzene) and BCP(2 ,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) may be included.

Preferably, the electron transport layer 225 may include 4,7-diphenyl-1,10-phenanthroline (BPhen).

The electron injection layer 226 may serve to inject electrons injected from the second electrode 227 into the emission layer.

For example, the electron injection layer 226 may include an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth metal compound, a rare earth metal compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof. At least one may be included, and preferably, the electron injection layer 226 may include lithium quinolate (Liq).

The second electrode 227 may be commonly connected to a power voltage to inject electrons into the electron transport layer.

For example, the second electrode 227 may include at least one of a metal material, an ionized metal material, an alloy material, a metal ink material in a colloidal state in a predetermined liquid, and a transparent metal oxide.

Specific examples of the metal material include lithium fluoride/aluminum (LiF/Al), lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), and magnesium-indium (Mg). -In), magnesium-silver (Mg-Ag), ytterbium (Yb), platinum (Pt), gold (Au), nickel (Ni), copper (Cu), barium (Ba), silver (Ag), silver nano At least one of wire (AgNWs), indium (In), ruthenium (Ru), lead (Pd), rhodium (Rh), iridium (Ir), osmium (Os), calcium (Ca), and cesium (Cs) is included. can do. In addition, carbon (C), a conductive polymer, or a combination thereof may be used as the metal material.

The carbon (C) material may include at least one of carbon nanotubes (CNT) and graphene, and the conductive polymer material may include polyethylenedioxythiophene:polystyrenesulfonate (PEDOT:PSS). can

In addition, the transparent metal oxide may include at least one of indium tin oxide (ITO), fluorine-doped tin oxide (FTO), antimony tin oxide (ATO), and aluminum doped zinc oxide (AZO).

Preferably, the second electrode 227 may be formed of magnesium-silver (Mg-Ag).

The capping layer 228 may include at least one of Alq3 (Tris(8-hydroxyquinolinato)aluminium), NPB, and molybdenum trioxide (MoO _{3 ).} Preferably, the capping layer 228 _{is formed of an inorganic capping layer based on molybdenum trioxide (MoO 3} ) to prevent penetration of the epoxy filler 240 into the organic light emitting layers 222 to 228 .

Meanwhile, the organic emission layers 221 to 228 may further include a charge generation layer, preferably, the charge generation layer may include 1,4,5,8,9,11-hexaazatriphenylene hexacarbonitrile (HAT-CN). can

3 is a diagram for explaining an energy band diagram of an organic light emitting diode according to an exemplary embodiment.

Referring to FIG. 3 , in reference numeral 300 'NPB' denotes the energy band of the hole transport layer, 'BPhen' denotes the energy band of the electron transport layer, and 'Liq' denotes the energy band of the electron injection layer.

In addition, in reference numeral 300, 'MoO ₃ ' denotes the energy band of the capping layer, 'HAT-CN' denotes the energy band of the charge generation layer, and 'Bebq2' and 'Ir(mphmq)2(tmd)' denote the light emitting layer. represents the energy band of 'Al' and 'Ag' represents the energy band of the first electrode, and 'Mg:Ag' represents the energy band of the second electrode.

Referring to reference numeral 300, since electron and hole mobility are significantly different in the case of an organic material, the organic light emitting device according to an embodiment may apply an electron transport layer (ETL) and a hole transport layer (HTL), through which By effectively moving electrons and holes to the light emitting layer, luminous efficiency can be increased.

4 is a view for explaining characteristics of a nano-wrinkle pattern of an organic light emitting diode according to an embodiment.

4, (a) and (c) of Figure 4 (a) and (c) of SEM (scanning electron microscopy) when the thickness of the metal layer of the master mold (master mold) for forming the nano-wrinkle pattern according to an embodiment is 10 nm Images and atomic force microscopy (AFM) images are shown, respectively.

In addition, FIGS. 4 (b) and (c) show an SEM image and an AFM image, respectively, when the thickness of the metal layer of the master mold for forming a nano-wrinkle pattern according to an embodiment is 25 nm.

For example, the metal layer of the master mold may be an aluminum (Al) metal layer.

According to (a) to (d) of Figure 4, the nano-wrinkle pattern shows a wrinkled structure of a small pitch when the thickness of the metal layer is thin, and it can be confirmed that when the thickness of the metal layer is increased, a wrinkle structure of a relatively large pitch is shown.

5A to 5H are diagrams for explaining characteristics of an organic light emitting diode according to an exemplary embodiment.

Referring to FIGS. 5A to 5H , reference numerals 510 to 520 denote an organic light-emitting device without a nano-wrinkle pattern (Reference) and an organic light-emitting device having a nano-wrinkle pattern according to an embodiment (Device A, Device B) The measurement results of the characteristics of

Specifically, reference numeral 510 denotes current density-voltage-luminescence (JVL) characteristics of Reference, Device A, and Device B, and reference numeral 520 denotes luminance-current efficiency and power efficiency. efficiency), reference numeral 530 denotes an external quantum efficiency (EQE) and luminance characteristic, and reference numeral 540 denotes an angular luminance distribution characteristic.

In addition, reference numerals 540 to 570 each show Reference, Device A and Device B, respectively, peak wavelength shift characteristics and full width at half maximum characteristics, and reference numeral 580 is Reference, Device A and The angular color shift characteristics in Device B's color coordinate system (CIE 1976) are shown.

On the other hand, Device A means an organic light emitting device having a nano-wrinkle pattern formed from a master mold having a metal layer thickness of 10 nm, and Device B is an organic light-emitting device having a nano-wrinkle pattern formed from a master mold having a metal layer thickness of 25 nm. means a light emitting device.

Referring to reference numerals 510 to 580, the device characteristics of Reference, Device A, and Device B may be derived as shown in Table 1 below.

In addition, the color shift characteristics of Reference, Device A, and Device B can be derived as shown in Table 2 below.

In addition, the peak wavelength shift values and half-width values of Reference, Device A, and Device B may be derived as shown in Table 3 below.

According to Tables 1 to 3, in the organic light emitting devices (Device A and Device B) according to an embodiment, light is reflected at various non-parallel angles due to diffuse reflection in the nano-wrinkle pattern to improve the viewing angle dependence. In particular, it can be seen that the viewing angle improvement and color change rate are very excellent when applied to the outside.

In addition, in the organic light emitting devices (Device A and Device B) according to an embodiment, by applying an epoxy filler between the organic light emitting layer and the encapsulation glass, it is possible to minimize the reduction in current and power efficiency due to the application of the nano-wrinkle pattern. It can be confirmed that there is

6 is a view for explaining a light scattering effect of an organic light emitting diode according to an exemplary embodiment.

Referring to FIG. 6, (a) of FIG. 6 shows the observation result of a light scattering effect of an organic light emitting device having a randomly distributed nano-wrinkle pattern, and FIG. 6(b) is a nano-wrinkle pattern. The observation result of the light scattering effect of the organic light emitting element which is not provided with a pattern is shown.

According to (a) and (b) of Figure 6, the organic light-emitting device according to an embodiment has a nano-wrinkle pattern, it can be confirmed that the total reflection of light, compared to the organic light-emitting device not provided with the nano-wrinkle pattern. It can be seen that more light can be combined.

7 is a view for explaining a blocking characteristic of a black tint phenomenon of an organic light emitting diode according to an exemplary embodiment.

Referring to FIG. 7 , (a) of FIG. 7 shows an image of a black tint effect of an organic light emitting diode (Reference) not having a nano-wrinkle pattern, and FIGS. 7(b) and (c) ) shows an image of the black tint effect of an organic light-emitting device (b: Device A, c: Device B) having a nano-wrinkle pattern.

Here, Device A means an organic light emitting device having a nano-wrinkle pattern formed from a master mold having a metal layer thickness of 10 nm, and Device B is an organic light-emitting device having a nano-wrinkle pattern formed from a master mold having a metal layer thickness of 25 nm. means a light emitting device.

According to (a) to (c) of Figure 7, the organic light emitting device (Device A, Device B) according to an embodiment, unlike the organic light emitting device (Reference) that does not have a nano-wrinkle pattern, almost found a black tint effect. It can be confirmed that, when the nano-wrinkle pattern is applied, the black tint effect generated from the organic light-emitting device can be greatly suppressed.

8 is a view for explaining a method of manufacturing an organic light emitting device according to an exemplary embodiment.

In other words, FIG. 8 is a view for explaining a method of manufacturing an organic light emitting device according to an exemplary embodiment described with reference to FIGS. 1 to 7 . Hereinafter, an organic light emitting device according to an exemplary embodiment of the contents described with reference to FIG. 8 . A description that overlaps with the content described through will be omitted.

Referring to FIG. 8 , in step 810 , in the method of manufacturing an organic light emitting device according to an embodiment, a substrate including an epoxy layer on which a nano-wrinkle pattern is formed may be formed.

Here, the substrate may include an epoxy layer in which a nano-wrinkle pattern is formed on a surface adjacent to the light emitting layer.

Next, in step 820 , in the method of manufacturing an organic light emitting device according to an embodiment, an organic light emitting layer may be formed on a substrate.

According to one side, in step 820, the method of manufacturing an organic light emitting device according to an embodiment may be formed by stacking a first electrode, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, a second electrode, and a capping layer. can

Next, in step 830 , in the method of manufacturing an organic light emitting device according to an embodiment, an epoxy filler may be formed between the organic light emitting layer and the encapsulation glass.

Next, in step 840 , in the method of manufacturing an organic light emitting device according to an embodiment, encapsulation glass may be formed on the substrate to cover the organic light emitting layer.

9 is a view for explaining a method of manufacturing a substrate on which a nano-wrinkle pattern is formed according to an embodiment.

In other words, the method of manufacturing the epoxy layer described below with reference to FIG. 9 may be performed in step 810 of FIG. 8 .

Referring to FIG. 9 , in step 910 , in the method of manufacturing a substrate according to an embodiment, a master mold 911 having a nano-wrinkle structure may be manufactured.

Next, in step 920 , in the method of manufacturing a substrate according to an embodiment, an epoxy material 921 may be applied on the master mold 911 . For example, the epoxy material 921 may be NOA 81 (Norland Products, Inc.).

Next, in step 930 , the method of manufacturing a substrate according to an embodiment includes a glass substrate 931 through an imprinting process using a master mold 911 and a glass substrate 931 coated with an epoxy material 921 . ), an epoxy layer 921 having a nano-wrinkle pattern formed thereon may be formed.

According to one side, during the imprinting process, a portion of the metal material constituting the metal layer of the master mold 911 may remain in the epoxy material 921 , and current leakage occurs due to the metal material remaining in the epoxy material 921 . can be

Accordingly, in step 930 , in the method of manufacturing the substrate according to the exemplary embodiment, the metal material remaining in the epoxy material 921 may be removed by using a wet etching method.

Next, in step 940 , in the method of manufacturing a substrate according to an embodiment, the epoxy layer 921 on which the nano-wrinkle pattern is formed may be UV-cured.

Next, in step 950, the method of manufacturing a substrate according to an embodiment includes ultrasonicating the UV-cured epoxy layer 921 with isopropyl alcohol, and performing UV-ozone treatment. , organic contaminants and/or particles remaining on the epoxy layer 921 may be removed.

10 is a view for explaining a method of manufacturing a master mold according to an embodiment.

In other words, the method of manufacturing the master mold described below with reference to FIG. 10 may be performed at step 910 of FIG. 9 .

Referring to FIG. 10 , in step 1010 , in the method of manufacturing a master mold according to an embodiment, a polymer layer 1013 may be formed on a mold substrate 1011 .

For example, the mold substrate 1011 may be implemented as a glass substrate, and the polymer layer 1013 may be implemented as a polydimethylsiloxane (PDMS) film.

In addition, in step 1010 , in the method of manufacturing the master mold according to an embodiment, a polymer material 1012 is applied to the mold substrate 1011 by a spin coating method to form a polymer layer 1013 on the mold substrate 1011 . there is.

Next, in step 1020 , in the method of manufacturing the master mold according to the embodiment, the mold substrate 1011 on which the polymer layer 1013 is formed may be heat-treated at a first temperature. For example, the first temperature may be 100 °C to 250 °C.

Preferably, in step 1020 , in the method of manufacturing the master mold according to the embodiment, the mold substrate 1011 on which the polymer layer 1013 is formed may be heat-treated at a temperature of 200° C. for 30 minutes.

Next, in step 1030 , the method of manufacturing the master mold according to the embodiment may deposit a metal layer 1031 on the heat-treated polymer layer 1013 .

For example, in step 1030 , in the method of manufacturing the master mold according to the embodiment, the metal layer 1031 may be formed by continuously depositing an aluminum (Al) material on the heat-treated polymer layer 1013 .

Next, in step 1040, in the method of manufacturing the master mold according to an embodiment, the metal layer 1031 may be formed into a nano-wrinkled structure by cooling the polymer layer 1013 on which the metal layer 1031 is deposited to a second temperature. . For example, the second temperature may be a room temperature of 15 °C to 30 °C, but is not limited thereto and may be a temperature lower than 15 °C.

That is, in the method of manufacturing the master mold according to an embodiment, the heat treatment process and the cooling process are sequentially performed, so that the metal layer 1031 has a nano-wrinkled structure due to the difference in the coefficients of thermal expansion between the polymer layer 1013 and the metal layer 1031 . can be formed with

According to one side, in step 1040, the method of manufacturing the master mold according to the embodiment can control the thickness of the metal layer formed by deposition on the heat-treated polymer layer, and through this, the nano provided in the organic light emitting device according to the embodiment. Values of pitch and depth of the wrinkle pattern may be controlled.

As a result, by using the present invention, it is possible to improve viewing angle dependence and color shift characteristics and block black tint by including the nanostructure.

In addition, by including the epoxy filler, it is possible to minimize a decrease in current efficiency.

As described above, although the embodiments have been described with reference to the limited drawings, various modifications and variations are possible from the above description by those of ordinary skill in the art. For example, the described techniques are performed in an order different from the described method, and/or the described components, such as devices, structures, devices, circuits, etc., are combined or combined in a different form than the described methods, or other components Or substituted or substituted by equivalents may achieve an appropriate result.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

100: organic light emitting device 110: substrate
120: organic light emitting layer 130: encapsulation glass
140: epoxy filler

Claims (11)

a substrate having an epoxy layer on which a nano-wrinkle pattern is formed;
an organic light emitting layer formed on the substrate; and
Encapsulation glass formed on the substrate to cover the organic light emitting layer
An organic light emitting device comprising a. According to claim 1,
An epoxy filler formed between the organic light emitting layer and the encapsulation glass, characterized in that it further comprises
organic light emitting device. According to claim 1,
The organic light emitting layer,
The first electrode, the hole injection layer, the hole transport layer, the light emitting layer, the electron transport layer, the electron injection layer, the second electrode and the capping layer are formed by stacking.
organic light emitting device. According to claim 1,
The epoxy layer on which the nano-wrinkle pattern is formed,
It is formed through a master mold having a nano-wrinkle structure,
The master mold,
A polymer layer and a metal layer formed on the polymer layer, wherein the metal layer is formed in the nano-wrinkled structure due to a difference in coefficient of thermal expansion with the polymer layer
organic light emitting device. According to claim 1,
The epoxy layer on which the nano-wrinkle pattern is formed,
The values of the pitch and depth of the nano-wrinkle pattern are determined according to the thickness of the metal layer.
organic light emitting device. Forming a substrate having an epoxy layer on which a nano-wrinkle pattern is formed
forming an organic light emitting layer on the substrate; and
forming an encapsulation glass on the substrate to cover the organic light emitting layer
including,
The substrate is
Comprising an epoxy layer in which the nano-wrinkle pattern is formed on a surface adjacent to the organic light emitting layer
A method of manufacturing an organic light emitting device. 7. The method of claim 6,
Forming an epoxy filler between the organic light emitting layer and the encapsulation glass
Method of manufacturing an organic light emitting device further comprising a. 7. The method of claim 6,
Forming the substrate comprises:
manufacturing a master mold having a nano-wrinkle structure;
applying an epoxy material on the master mold;
forming an epoxy layer having the nano-wrinkle pattern formed on the glass substrate through an imprinting process using a master mold and a glass substrate coated with the epoxy material;
UV curing the epoxy layer on which the nano-wrinkle pattern is formed
A method of manufacturing an organic light emitting device comprising a. 9. The method of claim 8,
The step of manufacturing the master mold,
forming a polymer layer on the mold substrate;
heat-treating the mold substrate on which the polymer layer is formed at a first temperature;
depositing a metal layer on the heat-treated polymer layer; and
Cooling the polymer layer on which the metal layer is deposited to a second temperature to form the metal layer into a nano-wrinkled structure
A method of manufacturing an organic light emitting device comprising a. 10. The method of claim 9,
The step of forming the metal layer into a nano-wrinkle structure,
Due to the difference in the coefficient of thermal expansion of the polymer layer and the metal layer, the metal layer is formed in a nano-wrinkled structure.
A method of manufacturing an organic light emitting device. 10. The method of claim 9,
depositing the metal layer,
By controlling the thickness of the metal layer deposited on the heat-treated polymer layer, to control the values of the pitch (pitch) and the depth (depth) of the nano-wrinkle pattern
A method of manufacturing an organic light emitting device.

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