WO2022015074A1

WO2022015074A1 - Organic light-emitting device including nano-island structures for obtaining color stability and method for manufacturing same

Info

Publication number: WO2022015074A1
Application number: PCT/KR2021/009101
Authority: WO
Inventors: 서민철
Original assignee: 경희대학교산학협력단
Priority date: 2020-07-15
Filing date: 2021-07-15
Publication date: 2022-01-20

Abstract

The present invention relates to an organic light-emitting device and a method for manufacturing same, and an organic light-emitting device according to an embodiment includes: a substrate on which at least one nano-island structure is formed; and an organic light-emitting structure formed on the substrate, wherein, as the substrate, an inorganic material layer is formed, and the formed inorganic material layer is exposed to an environment including a preset temperature and humidity conditions to form nano-island structures.

Description

An organic light emitting device having a nano-island structure to ensure color stability and a method for manufacturing the same

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 forming a nano-island structure on one side of a substrate provided in an organic light emitting device.

The external quantum efficiency of an organic light emitting diode (OLED) is theoretically calculated as in Equation 1 below.

[Equation 1]

here,

is the external quantum efficiency,

is the internal quantum efficiency,

Silver light extraction efficiency,

is the amount of exciton produced,

denotes 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 organic light emitting device and optimize the device.

In order to balance the charge of the organic light emitting diode, 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). In this case, the recombination zone is affected by electron and hole injection characteristics. When it is assumed 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 depending on 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 approach approaches 80%.

Accordingly, in the prior art, various external light extraction techniques such as a light diffusion film, a high refractive substrate, and an internal light scattering layer application are being studied to minimize light loss. It maximizes the external light efficiency of small displays.

However, in these technologies, since the light to the front is strengthened and the light is weakened to the side, it is necessary to consider the introduction of an omnidirectional scatterer in order to solve the problem of such deterioration of the viewing angle characteristics. ) was introduced to suppress the deterioration of the viewing angle characteristics in the microresonant device.

However, these studies have a problem in that it is difficult to apply them to an actual process because the manufacturing process is complicated.

An object of the present invention is to provide an organic light-emitting device capable of improving viewing angle characteristics by using a nano-island structure formed using an inorganic material as an omnidirectional scatterer of the organic light-emitting device, and a method for manufacturing the same.

Another object of the present invention is to provide an organic light emitting device capable of improving color shift and light distribution characteristics by reflecting light in all directions within the organic light emitting device due to the nano-island structure, and a method for manufacturing the same.

An organic light emitting device according to an embodiment of the present invention includes a substrate on which at least one nano-island structure is formed and an organic light emitting structure formed on the substrate, wherein the substrate includes an inorganic material layer and the formed inorganic material The layer may be exposed to an environment of predetermined temperature and humidity conditions to form a nano-island structure.

According to one side, the inorganic layer is at least one of cesium chloride (CsCl), cesium fluoride (CsF), cesium iodide (CsI), cesium bromide (CsBr), calcium chloride (CaCl ₂ ) and lanthanum chloride (LaCl ₃ ) may include

According to one side, the pitch and depth of the nano-island structure may be adjusted according to the thickness of the formed inorganic material layer.

According to one side, the inorganic material layer may be formed on the substrate to a thickness of 25 nm to 200 nm.

According to one side of the substrate, the formed inorganic layer is exposed to an environment of a temperature of 5° C. to 40° C. and a humidity of 30% to 100% to form a nano-island structure.

According to one side, the organic light emitting structure 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.

A method of manufacturing an organic light emitting device according to an embodiment of the present invention comprises the steps of forming at least one nano-island structure on a substrate and forming the organic light emitting structure on the substrate on which the nano-island structure is formed. and forming the nano-island structure by exposing the inorganic material layer formed on the substrate to an environment of preset temperature and humidity conditions to form the nano-island structure.

According to one side, forming the nano-island structure may form an inorganic material layer on the substrate to a thickness of 25 nm to 200 nm.

According to one side, in the step of forming the nano-island structure, the formed inorganic material layer is exposed to an environment of a temperature of 5° C. to 40° C. and a humidity of 30% to 100% to form a nano-island structure.

According to one embodiment, in the present invention, the viewing angle characteristic can be improved by using the nano-island structure as an omnidirectional scatterer of the organic light emitting device.

According to one embodiment, according to the present invention, light is reflected in all directions in the organic light emitting device due to the nano-island structure, thereby improving color shift and light distribution characteristics.

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

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

3A to 3C are diagrams for explaining device characteristics of an organic light emitting device according to an exemplary embodiment.

4A to 4G are diagrams for explaining optical characteristics of an organic light emitting diode according to an exemplary embodiment.

5A to 5D are diagrams for explaining characteristics according to a change in the thickness of an inorganic material layer of an organic light emitting diode according to an exemplary embodiment.

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

7A to 7B are diagrams for explaining a method of manufacturing a nano-island structure according to an embodiment.

Specific structural or functional descriptions of the embodiments according to the concept of the present invention disclosed in this specification 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 the present invention, a first element may be named 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 may be directly connected or connected to the other component, but it is understood that other components may exist in between. it should be On the other hand, when it is said 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 the middle. 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 the present 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 and 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 embodiments. Like reference numerals in each figure indicate like elements.

Referring to FIG. 1 , the organic light emitting device 100 according to an embodiment may improve viewing angle characteristics by using the nano-island structure as an omnidirectional scatterer of the organic light emitting device.

In addition, the organic light emitting device 100 may improve color shift and light distribution characteristics by reflecting light in all directions within the organic light emitting device due to the nano-island structure.

To this end, the organic light emitting device 100 may include a substrate 110 on which at least one or more nano-island structures (NI) are formed, and an organic light emitting structure 120 formed on the substrate 110 . have.

Specifically, in the substrate 110 according to an embodiment, an inorganic material layer 111 is formed, and the formed inorganic material layer 111 is exposed to an environment of preset temperature and humidity conditions to form a nano-island structure NI. can

For example, the substrate 110 may be a glass substrate, and the inorganic layer 111 may be cesium chloride (CsCl), cesium fluoride (CsF), cesium iodide (CsI), or cesium bromide (CsBr). ), calcium chloride (CaCl ₂ ), and lanthanum chloride (LaCl ₃ ) It may include at least one. Preferably, the inorganic material layer 111 may be a cesium chloride layer.

According to one side, in the nano-island structure NI, a pitch and a depth may be adjusted according to the thickness of the formed inorganic material layer 111 , and preferably, the inorganic material layer 111 has a thickness of 25 nm to 200 nm. The thickness may be formed on the substrate 110 .

In addition, in the substrate 110 , the formed inorganic material layer 111 is exposed to an environment of a temperature of 5° C. to 40° C. and a humidity of 30% to 100% to form a nano-island structure (NI). Preferably, the nano-island structure (NI) may be formed under a temperature condition of 27° C. and a humidity condition of 50%.

Specifically, the nano-island structure (NI) has a cesium chloride layer thermally deposited on one side of the substrate 110, that is, the inorganic material layer 111 in a temperature range of 5° C. or more to 40° C. or less, and 30% or more to 100 It may be formed through dewetting of the inorganic material layer 111 generated by exposure to an environment within a humidity range of less than %, wherein the nano-island structure (NI) has at least one shape of a hemispherical shape, an oval shape, and an irregular shape. can be formed with

According to one side, the organic light emitting structure 120 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.

For example, the organic light emitting structure 120 may be a top light emitting device (eg, a front resonance device) or a bottom light emitting device (eg, a rear resonance device).

According to one side, the nano-island structure NI may be formed on the upper portion of the substrate 110 when the organic light emitting structure 120 is a top light emitting device, that is, between the substrate 110 and the organic light emitting structure 120 . . Also, when the organic light emitting structure 120 is a bottom light emitting device, the nano-island structure NI may be formed under the substrate 110 .

The organic light emitting structure 120 according to an embodiment will be described in more detail later with reference to FIG. 2 .

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

Referring to FIG. 2 , the organic light emitting device 200 according to an embodiment includes a substrate 210 on which at least one nano-island structure (NI) is formed, and an organic light emitting structure 220 formed on the substrate 210 . may include

Specifically, the substrate 210 may have an inorganic material layer 211 formed thereon, and the formed inorganic material layer 211 may be exposed to an environment of preset temperature and humidity conditions to form a nano-island structure NI.

In addition, the organic light emitting structure 220 includes 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 , and a second electrode. 227 and the capping layer 228 may be stacked.

For example, the first electrode 221 may be an 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 224 , and may be formed of a transmissive electrode, a reflective electrode, or a stacked structure thereof.

Transmissive electrode materials include 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 be 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 the thermal properties, the coating speed of about 2,000 rpm to 5,000 rpm, and the heat treatment temperature for removing the solvent after coating may be appropriately selected in a 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 the holes injected from the first electrode to the light emitting layer 224, 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-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(pbutylphenyl)) diphenylamine)] It may contain one.

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 have.

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-κN) as a dopant material. phenyl-κC] (2,2,6,6-tetramethyl-3,5-heptanedionato-κO3 (Ir(mphmq)2tmd).

The electron transport layer 225 may serve to move electrons injected from the second electrode 160 to the light emitting layer 224 . For example, the electron transport layer 225 may include 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).

Meanwhile, the hole transport layer 223 further includes an electron leakage control layer formed on a surface adjacent to the emission layer 224 , and the electron transport layer 225 includes a hole leakage control layer formed on a surface adjacent to the emission layer 224 . It may further include, wherein the electron leakage control layer and the hole leakage control layer is a high efficiency, high efficiency, It is possible to implement an organic light emitting structure having low voltage and long life characteristics.

Specifically, in the organic light emitting structure according to an embodiment, whether the HOMO-LUMO state density of the electron leakage control layer and the hole leakage control layer overlaps between the HOMO-LUMO state density of the host material contained in the light emitting layer 224 ( (eg, overlap ratio) can be adjusted within a predetermined range.

For example, based on the LUMO state density, the LUMO state density of the host and the LUMO state density of the hole leakage control layer overlap each other, and the LUMO state density of the host and the LUMO state density of the electron-leakage control layer are adjusted so that they do not overlap. can be

That is, electrons move along the LUMO energy level, and when the LUMO density of states between the hole leakage control layer and the host overlaps with each other in terms of LUMO density of states, the density of states from the hole leakage control layer to the host (LUMO density of states) overlap. Through this, it is possible to achieve a rapid electron transfer effect, thereby increasing the efficiency of the organic electroluminescent device. In addition, when there is no overlap (overlapping) of the LUMO density of states between the electron leakage control layer and the host, the electron blocking effect can be exhibited by suppressing the diffusion or movement of electrons moving to the light emitting layer 224 to the electron leakage control layer. Accordingly, it is possible to exhibit long life characteristics by preventing an irreversible decomposition reaction due to oxidation, which occurs when electrons move beyond the light emitting layer 224 to the hole transport layer 30, and a decrease in the lifespan of the organic light emitting device.

For example, the electron leakage control layer includes at least one selected from the group consisting of an arylene group, a heteroarylene group, hydrogen, deuterium, a halogen group, a cyano group, a nitro group, and an amino group, and the hole leakage control layer includes a moiety (eg, , EDG group, EWG group), but is not limited thereto.

The electron injection layer 226 may serve to inject electrons injected from the second electrode 227 into the emission layer 224 .

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 may be formed of an inorganic capping layer based on _{molybdenum trioxide (MoO 3 ).}

According to one side, the organic light emitting structures 221 to 228 may further include a charge generation layer, preferably, the charge generation layer is 1,4,5,8,9,11-hexaazatriphenylene hexacarbonitrile (HAT-CN) may include

3A to 3C , reference numeral 310 denotes voltage-current density characteristics of an existing organic light-emitting device (Reference) and an organic light-emitting device (Devices A, B, and C) according to an embodiment. In the figure, reference numeral 320 denotes luminance-current density characteristics of an existing organic light emitting device (Reference) and an organic light emitting device (Device A, B, C) according to an embodiment, and reference numeral 330 . shows the luminance-external quantum efficiency (luminance-EQE) characteristics of the conventional organic light-emitting device (Reference) and the organic light-emitting devices (Devices A, B, and C) according to an embodiment.

Specifically, the conventional organic light-emitting device (Reference) refers to a front resonance device manufactured by a general deposition method, and the organic light-emitting devices (Devices A, B, and C) according to an embodiment have different thicknesses of the inorganic material layers to each other. It refers to an organic light emitting device according to an embodiment in which nano-island structures of different shapes are formed.

Here, Device A refers to an organic light-emitting device in which a nano-island structure is formed through an inorganic material layer formed to a thickness of 25 nm to 75 nm, and Device B is an organic light-emitting device in which a nano-island structure is formed through an inorganic material layer formed to a thickness of 75 nm to 125 nm. means, and Device C refers to an organic light emitting device in which a nano-island structure is formed through an inorganic material layer formed to a thickness of 125 nm to 175 nm.

Referring to reference numerals 310 to 330, device characteristics of the conventional organic light emitting device (Reference) and the organic light emitting devices (Devices A, B, and C) according to an embodiment may be summarized as shown in Table 1 below.

ItemItem		ReferenceReference	Device ADevice A	Device BDevice B	Device CDevice C
구동 전압(Oprating voltage)(V)Operating voltage (V)	1000 cd/m² 1000 cd/m ²	4.44.4	4.64.6	4.74.7	5.35.3
전류 효율(Current efficiency)(cd/A)Current efficiency (cd/A)	MaxMax	58.6(1.00)58.6 (1.00)	26.0(0.44)26.0 (0.44)	18.2(0.31)18.2 (0.31)	17.0(0.29)17.0 (0.29)
전류 효율(Current efficiency)(cd/A)Current efficiency (cd/A)	1000 cd/m² 1000 cd/m ²	55.9(1.00)55.9 (1.00)	25.9(0.46)25.9 (0.46)	18.2(0.32)18.2 (0.32)	16.5(0.30)16.5 (0.30)
전력 효율(Power efficiency)(lm/W)Power efficiency (lm/W)	MaxMax	47.5(1.00)47.5 (1.00)	20.0(0.42)20.0 (0.42)	14.7(0.31)14.7 (0.31)	14.4(0.30)14.4 (0.30)
전력 효율(Power efficiency)(lm/W)Power efficiency (lm/W)	1000 cd/m² 1000 cd/m ²	29.3(1.00)29.3 (1.00)	16.7(0.57)16.7 (0.57)	11.1(0.38)11.1 (0.38)	9.0(0.31)9.0 (0.31)
외부 양자 효율(EQE)(%)External Quantum Efficiency (EQE) (%)	MaxMax	19.2(1.00)19.2 (1.00)	13.0(0.68)13.0 (0.68)	9.6(0.50)9.6 (0.50)	9.0(0.47)9.0 (0.47)
외부 양자 효율(EQE)(%)External Quantum Efficiency (EQE) (%)	1000 cd/m² 1000 cd/m ²	18.2(1.00)18.2 (1.00)	13.0(0.72)13.0 (0.72)	9.6(0.53)9.6 (0.53)	8.6(0.47)8.6 (0.47)

4A to 4G , reference numeral 410 denotes the wavelength-intensity characteristics (ie, the wavelength-intensity) of the conventional organic light-emitting device (Reference) and the organic light-emitting devices (Devices A, B, and C) according to an embodiment. Each EL (angular EL) spectrum change) characteristic is shown, and reference numeral 420 denotes a viewing angle of an existing organic light emitting device (Reference) and an organic light emitting device (Device A, B, C) according to an embodiment - color shift (viewing angle) - color shift) characteristics, and reference numeral 430 denotes angular luminance distribution characteristics of the conventional organic light emitting device (Reference) and the organic light emitting device (Device A, B, C) according to an embodiment. show

In addition, each of reference numerals 440 to 470 denotes a wavelength-intensity characteristic according to an angle ranging from 0° to 60° between the conventional organic light-emitting device (Reference) and the organic light-emitting device (Device A, B, and C) according to an embodiment. - intensity) is shown.

Referring to reference numerals 410 to 470, optical characteristics of the conventional organic light emitting device (Reference) and the organic light emitting devices (Devices A, B, and C) according to an embodiment may be summarized as shown in Table 2 below.

ItemItem		ReferenceReference	Device ADevice A	Device BDevice B	Device CDevice C
(x, y)^a (x, y) ^a	1000 cd/m² 1000 cd/m ²	(0.642, 0.358)(0.642, 0.358)	(0.639, 0.360)(0.639, 0.360)	(0.637, 0.362)(0.637, 0.362)	(0.633, 0.366)(0.633, 0.366)
반치폭(FWHM)(nm)Full width at half maximum (FWHM) (nm)	1000 cd/m² 1000 cd/m ²	34.334.3	39.639.6	42.542.5	44.444.4
피크 파장(Peak wavelength)(nm)Peak wavelength (nm)	1000 cd/m² 1000 cd/m ²	606606	605605	605605	604604
컬러 시프트(Color shift^b,c)Color shift ^b,c	1000 cd/m² 1000 cd/m ²	0.0590.059	0.0180.018	0.0130.013	0.0050.005
a: CIE 1931 color coordinates b: measured from 0°to 60° c: CIE 1976 chromaticity a: CIE 1931 color coordinates b: measured from 0° to 60° c: CIE 1976 chromaticity

That is, the organic light emitting devices (Devices A, B, and C) according to the exemplary embodiment apply a nano-island structure, so that light is reflected in all directions due to diffuse reflection in the device, thereby improving color shift and light distribution according to the viewing angle. It can be confirmed that there is

In addition, it can be seen that the organic light emitting devices (Devices A, B, and C) according to the exemplary embodiment have an increased width at half maximum (FWHM) compared to the conventional organic light emitting device (Reference) by applying the nano-island structure, which is a nanostructure. It was found that the microresonance effect was reduced according to the application.

On the other hand, even when the organic light emitting diode according to an embodiment is implemented as a rear resonance element, it was found that there is almost no reduction in efficiency compared to the front resonance element denoted by reference numerals 410 to 470. That is, the organic light emitting diode according to the exemplary embodiment can effectively improve the viewing angle in both the top light emitting device and the bottom light emitting device.

5A to 5D, reference numeral 510 denotes a nano-island structure of an organic light emitting device according to an embodiment formed through an inorganic material layer formed to a thickness of 50 nm, and reference numeral 520 denotes an inorganic material layer formed to a thickness of 100 nm. It shows the nano-island structure of the organic light emitting device according to an embodiment formed through.

In addition, reference numeral 530 denotes a nano-island structure of an organic light emitting device according to an embodiment formed through an inorganic material layer formed to a thickness of 150 nm, and reference numeral 540 denotes an inorganic material layer formed to a thickness of 200 nm according to an embodiment. A nano-island structure of an organic light emitting device is shown.

On the other hand, the nano-island structure shown in reference numerals 510 to 540 is exposed to an environment of a temperature of 5 ° C. to 40 ° C. and a humidity of 30% to 100% of the inorganic material layers formed with different thicknesses for 20 minutes (min). can be formed.

According to reference numerals 510 to 540, in the organic light emitting device according to an embodiment, it can be confirmed that nano-island structures having various shapes and sizes, such as spherical, oval, and irregular shapes, are formed according to the thickness of the inorganic layer.

In other words, FIG. 6 is a view for explaining an example of manufacturing an organic light emitting device according to an exemplary embodiment described with reference to FIGS. 1 to 5D . Among the contents described with reference to FIG. 6 below, FIG. 1 to FIG. 5D . A description that overlaps with the content will be omitted.

Referring to FIG. 6 , in step 610 , in the method of manufacturing an organic light emitting device according to an exemplary embodiment, at least one nano-island structure may be formed on a substrate.

Specifically, in the method of manufacturing an organic light emitting device according to an embodiment in step 610, the inorganic material layer formed on the substrate is exposed to an environment of preset temperature and humidity conditions to form a nano-island structure.

A method of manufacturing a nano-island structure according to an embodiment will be described in more detail later with reference to FIGS. 7A to 7B.

Next, in step 620 , in the method of manufacturing an organic light emitting device according to an embodiment, an organic light emitting structure may be formed on the substrate on which the nano-island structure is formed.

According to one side, in step 620, the method of manufacturing an organic light emitting device according to an embodiment includes sequentially 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. An organic light emitting structure may be formed.

In other words, the contents described below with reference to FIGS. 7A to 7B may be performed in operation 610 of FIG. 6 .

7A to 7B , in step 710 , the method of manufacturing the nano-island structure according to the embodiment may form an inorganic material layer 712 on a substrate 711 .

For example, the inorganic layer 712 may include cesium chloride (CsCl), cesium fluoride (CsF), cesium iodide (CsI), cesium bromide (CsBr), calcium chloride (CaCl ₂ ), and lanthanum chloride (LaCl ₃ ). may include at least one of Preferably, the inorganic layer 712 may be a cesium chloride layer.

According to one side, in the inorganic layer 712 , the pitch and depth of the nano-island structure described below may be adjusted according to the thickness of the inorganic layer 712 formed on the substrate 711 .

For example, in step 710 , the method of manufacturing the nano-island structure according to the embodiment may form the inorganic material layer 712 on the substrate 711 to a thickness of 25 nm to 200 nm.

Next, in step 720, the nano-island structure manufacturing method according to an embodiment exposes the substrate 711 on which the inorganic material layer 712 is formed to an environment of preset temperature and humidity conditions to form the nano-island structure (NI). can be formed

In other words, in step 720, in the method of manufacturing the nano-island structure according to the embodiment, the inorganic material layer 712 formed to a predetermined thickness is exposed to an environment of preset temperature and humidity conditions, so that the nano-island structure NI is formed. can be formed.

For example, in step 720, the method for manufacturing a nano-island structure according to an embodiment is that the formed inorganic material layer 720 is exposed to an environment of a temperature of 5° C. to 40° C. and a humidity of 30% to 100%, so that the nano- An island structure NI may be formed.

As a result, by using the present invention, the viewing angle characteristic can be improved by using the nano-island structure as an omnidirectional scatterer of the organic light emitting device.

In addition, when the present invention is used, light is reflected in all directions in the organic light emitting device due to the nano-island structure, thereby improving color shift and light distribution characteristics.

As described above, although the embodiments have been described with reference to the limited drawings, various modifications and variations are possible by those skilled in the art from the above description. 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 method, 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.

Claims

a substrate having at least one nano-island structure formed thereon; and

The organic light emitting structure formed on the substrate

including,

The substrate is

An inorganic material layer is formed, and the formed inorganic material layer is exposed to an environment of preset temperature and humidity conditions to form the nano-island structure

organic light emitting device.
According to claim 1,

The inorganic material layer,

containing at least one of cesium chloride (CsCl), cesium fluoride (CsF), cesium iodide (CsI), cesium bromide (CsBr), calcium chloride (CaCl 2 ) and lanthanum chloride (LaCl 3 )

organic light emitting device.
According to claim 1,

The nano-island structure,

The pitch and depth are adjusted according to the thickness of the formed inorganic material layer.

organic light emitting device.
4. The method of claim 3,

The inorganic material layer,

formed on the substrate with a thickness of 25 nm to 200 nm

organic light emitting device.
According to claim 1,

The substrate is

The formed inorganic material layer is exposed to an environment of a temperature of 5 ° C. to 40 ° C. and a humidity condition of 30% to 100% to form the nano-island structure.

organic light emitting device.
According to claim 1,

The organic light emitting structure,

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.
forming at least one or more nano-island structures on a substrate; and

Forming an organic light emitting structure on the substrate on which the nano-island structure is formed

including,

Forming the nano-island structure comprises:

The inorganic material layer formed on the substrate is exposed to an environment of preset temperature and humidity conditions to form the nano-island structure

A method of manufacturing an organic light emitting device.
8. The method of claim 7,

The inorganic material layer,

containing at least one of cesium chloride (CsCl), cesium fluoride (CsF), cesium iodide (CsI), cesium bromide (CsBr), calcium chloride (CaCl 2 ) and lanthanum chloride (LaCl 3 )

A method of manufacturing an organic light emitting device.
8. The method of claim 7,

Forming the nano-island structure comprises:

forming the inorganic material layer on the substrate to a thickness of 25 nm to 200 nm

A method for manufacturing an organic light emitting device.
8. The method of claim 7,

Forming the nano-island structure comprises:

The formed inorganic material layer is exposed to an environment of a temperature of 5 ° C. to 40 ° C. and a humidity condition of 30% to 100% to form the nano-island structure.

A method for manufacturing an organic light emitting device.