CN111200077A - Internal light extraction structure, organic light emitting device comprising same and manufacturing method thereof - Google Patents
Internal light extraction structure, organic light emitting device comprising same and manufacturing method thereof Download PDFInfo
- Publication number
- CN111200077A CN111200077A CN201910013105.3A CN201910013105A CN111200077A CN 111200077 A CN111200077 A CN 111200077A CN 201910013105 A CN201910013105 A CN 201910013105A CN 111200077 A CN111200077 A CN 111200077A
- Authority
- CN
- China
- Prior art keywords
- layer
- scattering
- light extraction
- perhydropolysilazane
- oxide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Images
Classifications
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K50/00—Organic light-emitting devices
- H10K50/80—Constructional details
- H10K50/85—Arrangements for extracting light from the devices
- H10K50/854—Arrangements for extracting light from the devices comprising scattering means
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K50/00—Organic light-emitting devices
- H10K50/80—Constructional details
- H10K50/85—Arrangements for extracting light from the devices
- H10K50/858—Arrangements for extracting light from the devices comprising refractive means, e.g. lenses
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
Landscapes
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Electroluminescent Light Sources (AREA)
Abstract
The present invention relates to an internal light extraction structure, characterized in that the internal light extraction structure comprises: a scattering layer formed on the substrate and including scattering particles that scatter light within a matrix formed by curing perhydropolysilazane; and a planarization layer formed on the scattering layer to planarize an uneven surface and including a matrix formed by curing perhydropolysilazane and high refractive index nanoparticles dispersed therein. The present invention also relates to an organic light emitting device comprising said internal light extraction structure. The present invention also relates to methods of preparing the internal light extraction structure and organic light emitting device.
Description
Technical Field
The present invention relates to an internal light extraction structure and an organic light emitting device including the same. And more particularly, to an internal light extraction structure that can improve light extraction efficiency of an organic light emitting device by eliminating an optical waveguide mode while securing transmittance, and an organic light emitting device including the same.
Background
Compared with the earlier developed inorganic light-emitting device, the organic light-emitting device (OLED) has the advantages of wide material selection range, capability of realizing full-color display, low driving voltage, high brightness and luminous efficiency, wide viewing angle, high response speed, relatively simple manufacturing process, low cost, capability of realizing flexible display and the like. Meanwhile, since the OLED has the characteristics of large-area film forming, low power consumption and other excellent characteristics, the OLED is an ideal plane light source, and has wide application prospect in the future energy-saving and environment-friendly illumination field.
The light emitting principle of the OLED is that when positive direct current voltage is applied to two electrodes, electrons and holes are respectively injected into an organic film from a cathode and an anode, current carriers migrate in an organic semiconductor material in opposite directions under the action of an electric field and meet to generate excitons, the excitons emit light compositely in a light emitting region, and the emitted light is emitted in all directions randomly, so that an external mode (light is emitted from the surface of a substrate), a substrate waveguide mode and an ITO/organic layer waveguide mode are formed due to the action of total reflection in the propagation process. According to classical ray optics theory, only a small fraction of the generated light can exit the substrate due to differences in refractive index, etc., between the glass substrate and the ITO/organic material, while the remaining majority of the light is either trapped in the glass substrate and the device in a waveguide mode or exits from the edge of the device. According to the calculation of the classical ray optical theory, the proportion of the external mode, the substrate waveguide mode and the ITO/organic layer waveguide mode in the traditional classical device is respectively 20%, 30% and 50%. The light emitted from the surface of the substrate (external mode) is only 20%, which is far from meeting the requirements of illumination and display applications, and it can be seen from the calculation results that most of the light generated by exciton recombination cannot be emitted from the substrate, which is the most important factor limiting the light-emitting efficiency of the OLED, and therefore, it is necessary to search for a method for improving the light extraction efficiency.
General light extraction methods can be divided into two categories: external light extraction and internal light extraction. The external light extraction method is applied to the outside of the device, is simple and easy to implement, can be respectively carried out with the preparation process of the device, has low cost and is easy for large-scale production, but can only extract the light trapped in the glass substrate, thereby limiting the light intensifying efficiency. The internal light extraction structure is built inside the device, and can extract light lost in the optical waveguide mode in the device. Therefore, the ability of the internal light extraction method to improve light extraction efficiency may be higher than the ability of the external light extraction method to improve light extraction efficiency.
However, the effect of using the internal light extraction method to improve the light extraction efficiency is still insignificant with respect to the amount of light emitted outward. Therefore, there is a need for active research into methods or techniques for further improving light extraction efficiency.
Disclosure of Invention
The invention provides an internal light extraction structure, which is characterized by comprising: a scattering layer formed on the substrate and including scattering particles that scatter light within a matrix formed by curing perhydropolysilazane; and a planarization layer formed on the scattering layer to planarize an uneven surface and including a matrix formed by curing perhydropolysilazane and high refractive index nanoparticles dispersed therein.
Another aspect of the present invention provides an organic light emitting device comprising the internal light extraction structure described above, and further comprising a first electrode, a second electrode, and an organic light emitting portion, wherein the first electrode, the organic light emitting portion, and the second electrode are sequentially disposed on the planarization layer of the internal light extraction structure.
In another aspect, the present invention provides a method for manufacturing the internal light extraction structure, including the following steps:
(1) mixing the scattering particles with a perhydropolysilazane solution to prepare a scattering layer mixed solution;
(2) coating the scattering layer mixed solution on a substrate;
(3) drying the coated scattering layer mixed solution;
(4) curing the dried scattering layer mixed solution to form a scattering layer;
(5) mixing the high-refractive-index nano particles with a perhydropolysilazane solution to prepare a planarization layer mixed solution;
(6) coating the planarization layer mixed solution on the scattering layer;
(7) drying the coated planarization layer mixed liquid;
(8) and curing the dried planarization layer mixed liquid to form a planarization layer.
The invention also provides a manufacturing method of the organic light-emitting device, which is characterized by comprising the following steps:
(1) mixing the scattering particles with a perhydropolysilazane solution to prepare a scattering layer mixed solution;
(2) coating the scattering layer mixed solution on a substrate;
(3) drying the coated scattering layer mixed solution;
(4) curing the dried scattering layer mixed solution to form a scattering layer;
(5) mixing the high-refractive-index nano particles with a perhydropolysilazane solution to prepare a planarization layer mixed solution;
(6) coating the planarization layer mixed solution on the scattering layer;
(7) drying the coated planarization layer mixed liquid;
(8) curing the dried planarization layer mixed liquid to form a planarization layer;
(9) on the planarization layer of the internal light extraction structure, a first electrode, an organic light emitting portion, and a second electrode are sequentially constructed.
Compared with the prior art, the invention has the following beneficial effects:
in the invention, the perhydropolysilazane solution is cured to form SiO2The mesh structure further forms an internal light extraction structure of the silicon dioxide matrix, and the light transmittance is high, so that the light extraction efficiency can be greatly improved when the mesh structure is applied to an organic light-emitting device.
The invention utilizes the SiO formed by the solidification of perhydropolysilazane2The matrix and the glass substrate have the same thermal expansion coefficient, can avoid the expansion and falling off of the film layer caused by temperature change in the evaporation process, and also has the characteristics of good uniformity and density, good chemical stability, heat shrinkage and expansion resistance and good wear resistance.
Drawings
In order that the present disclosure may be more readily and clearly understood, reference is now made to the following detailed description of the embodiments of the present disclosure taken in conjunction with the accompanying drawings, in which
Fig. 1 is a schematic view showing a cross section of an organic light emitting device of one embodiment of the present invention.
Fig. 2 is a schematic diagram showing a cross section of an internal light extraction structure of one embodiment of the present invention.
In the figure: 1-a substrate; 2-scattering layer, 21-scattering particles, 22-scattering matrix; 3-planarization layer, 31-high refractive index nanoparticles, 32-planarization matrix; 4-a first electrode; 5-an organic light-emitting portion; 6 a second electrode.
Fig. 3 is a schematic view showing a manufacturing process of an organic light emitting device according to an embodiment of the present invention.
Detailed Description
The following description of the embodiments of the present invention is provided by way of specific examples, and other advantages and effects of the present invention will be readily apparent to those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.
The following detailed description and accompanying drawings are included to provide a more detailed, exploded description of the presently claimed invention. It should be noted that like or similar reference numerals refer to the same or similar elements or elements having similar functions throughout. The embodiments described below with reference to the drawings are illustrative only and are not to be construed as limiting the application of the present invention.
The invention provides an internal light extraction structure, which is characterized by comprising: a scattering layer formed on the substrate and including scattering particles that scatter light within a matrix formed by curing perhydropolysilazane; and a planarization layer formed on the scattering layer to planarize an uneven surface and including a matrix formed by curing perhydropolysilazane and high refractive index nanoparticles dispersed therein.
In a preferred embodiment of the present invention, the substrate is a light transmissive plastic substrate or a glass substrate, and is, for example, a flexible material or a rigid material selected from the group consisting of: polyether sulfone resin, polyethylene, polyvinyl chloride, polytetrafluoroethylene, polyethylene terephthalate, polyethylene naphthalate, polyurethane, polyamide, polyimide, polyesteramide, polyetherimide, cycloolefin polymer, and glass.
In a preferred embodiment of the present invention, the scattering layer is prepared by a precursor derivation method, and the precursor is a perhydropolysilazane mixture containing scattering particles. That is, the scattering layer perhydropolysilazane mixture solution is a perhydropolysilazane solution containing scattering particles.
In a preferred embodiment of the present invention, the perhydropolysilazane has a number average molecular weight of 300-.
The determination of the number average molecular weight of the perhydropolysilazane is carried out by a Gel Permeation Chromatography (GPC) method according to the national standard GB/T21863-2008 of the people's republic of China (equivalent to the German standard DIN55672-1:2007 part 1 of the Gel Permeation Chromatography (GPC) method using Tetrahydrofuran (THF) as an elution solvent).
The solvent of the perhydropolysilazane solution is selected from toluene, dichloromethane, tetrahydrofuran, xylene, n-hexane, n-pentane, esters or ethers.
In a preferred embodiment of the present invention, the perhydropolysilazane is used in an amount of 15 to 50 wt%, preferably 20 to 40 wt%, more preferably 20 to 30 wt%, based on the total weight of the perhydropolysilazane solution.
In a preferred embodiment of the present invention, the scattering particles are used in an amount of 5 to 70 wt%, preferably 10 to 60 wt%, more preferably 15 to 50 wt%, based on the solid content of the perhydropolysilazane solution used, i.e., the solid content of the perhydropolysilazane contained, in the scattering layer perhydropolysilazane mixture solution.
In the present invention, the particle size of the scattering particles is 10 to 1000nm, preferably 50 to 800nm, and more preferably 100 to 600 nm.
The particle size in the present invention was measured using a nanometer laser particle sizer, model Malvern zetasizer nano-ZS, available from Malvern instruments, uk.
The scattering particles are inorganic or organic particles. In addition, the shape of the scattering particles is spherical, elliptical, or amorphous. For example, the scattering particles are one or more selected from titanium dioxide, silicon oxide, zirconium oxide, magnesium fluoride, aluminum oxide, polystyrene, acrylic resin, polyurethane, polytetrafluoroethylene, melamine resin, benzoguanamine resin, epoxy resin, or silicone resin.
In a preferred embodiment of the present invention, the planarization layer is prepared by a precursor derivation method, and the precursor is a perhydropolysilazane mixture solution containing high refractive index nanoparticles. That is, the planarizing layer perhydropolysilazane mixture solution is a perhydropolysilazane solution containing high-refractive-index nanoparticles.
In a preferred embodiment of the present invention, the high refractive index nanoparticles are used in an amount of 5 to 60 wt%, preferably 10 to 50 wt%, more preferably 15 to 45 wt%, based on the weight of the solid content of the perhydropolysilazane solution used, i.e., the solid content of the perhydropolysilazane contained, in the planarizing layer perhydropolysilazane mixture.
In the present invention, the reason why the high refractive index is required for the nanoparticles is: the light extraction layer formed by the nanoparticles with higher refractive index and the silica matrix is a mixed optical dense medium layer, thus reducing the total reflection of light at the electrode. The refractive index of the nanoparticles is therefore 2.2 or more, for example 2.2 to 2.5.
In the present invention, the high refractive index nanoparticles have a particle size of 1 to 20nm, preferably 1 to 15 nm.
The high-refractive-index nano particles are selected from more than one of titanium dioxide, zirconium oxide, indium tin oxide, cerium oxide, cadmium oxide, aluminum oxide, manganese dioxide, zinc oxide, niobium pentoxide, tantalum pentoxide, chromium oxide, nickel oxide, lead oxide, tin oxide, copper oxide, molybdenum oxide, silicon, hafnium oxide, manganese oxide, calcium carbonate, silicon carbide, silicon nitride, aluminum nitride, silver sulfide, zinc sulfide, barium sulfide, calcium sulfide, cadmium sulfide, barium titanate, zirconium titanate, lead chromate or polymer particles.
The inventors have found that the SiO obtained after the PHPS coating treatment2The coating layer has good abrasion resistance and light transmittance, and can fix the inner particles in the matrix layer.
The perhydropolysilazane mixture may be applied by a method known to those skilled in the art, such as spin coating, linear driving knife coating, dip coating, spray coating, and roll coating.
Another aspect of the present invention provides an organic light emitting device, which is characterized in that the organic light emitting device comprises the internal light extraction structure, and further comprises a first electrode, a second electrode and an organic light emitting portion, wherein the first electrode, the organic light emitting portion and the second electrode are sequentially disposed on a planarization layer of the internal light extraction structure.
In another aspect, the present invention provides a method for manufacturing the internal light extraction structure, including the following steps:
(1) mixing the scattering particles with a perhydropolysilazane solution to prepare a scattering layer mixed solution;
(2) coating the scattering layer mixed solution on a substrate;
(3) drying the coated scattering layer mixed solution;
(4) curing the dried scattering layer mixed solution to form a scattering layer;
(5) mixing the high-refractive-index nano particles with a perhydropolysilazane solution to prepare a planarization layer mixed solution;
(6) coating the planarization layer mixed solution on the scattering layer;
(7) drying the coated planarization layer mixed liquid;
(8) and curing the dried planarization layer mixed liquid to form a planarization layer.
In another aspect, the present invention provides a method for manufacturing an organic light emitting device, including:
(1) mixing the scattering particles with a perhydropolysilazane solution to prepare a scattering layer mixed solution;
(2) coating the scattering layer mixed solution on a substrate;
(3) drying the coated scattering layer mixed solution;
(4) curing the dried scattering layer mixed solution to form a scattering layer;
(5) mixing the high-refractive-index nano particles with a perhydropolysilazane solution to prepare a planarization layer mixed solution;
(6) coating the planarization layer mixed solution on the scattering layer;
(7) drying the coated planarization layer mixed liquid;
(8) curing the dried planarization layer mixed liquid to form a planarization layer;
(9) on the planarization layer of the internal light extraction structure, a first electrode, an organic light emitting portion, and a second electrode are sequentially constructed.
In the present invention, the first electrode is a transparent electrode formed on the planarization layer of the internal light extraction structure, and the first electrode and the second electrode may be opposite to each other. The first electrode may be an anode. The first electrode may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. When the first electrode is a transmissive electrode, the first electrode may be formed using a transparent metal oxide, such as Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), zinc oxide (ZnO), Indium Tin Zinc Oxide (ITZO), or the like. When the first electrode is a semi-transmissive electrode or a reflective electrode, the first electrode may include Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or a metal mixture. If the first electrode is ito, the patterned structure is typically formed, and may be formed by sputtering. The first electrode can be formed by a method such as sputtering, ion plating, vacuum evaporation, spin coating, electron beam evaporation, or Chemical Vapor Deposition (CVD), and is preferably formed by sputtering.
The first electrode is preferably a transparent metal oxide such as ITO, which has good light transmittance and a refractive index in the range of 1.8 to 2.0.
The thickness of the first electrode is 100-200 nm, preferably 120-200 nm.
The second electrode may be a cathode, which may be transparent or non-transparent material, such as a non-transparent metal electrode. The metal electrode as the second electrode can be an Al or mixed MgAg, AlAg metal electrode, or other conductive material with higher transmittance.
The thickness of the second electrode is 50-200 nm, preferably 60-150 nm.
In one embodiment of the present invention, the organic light emitting device of the present invention is a bottom emission type device, the first electrode is preferably a transparent metal oxide ITO, and the second electrode is a non-transparent metal electrode.
In one embodiment of the present invention, the first electrode layer is formed as an anode on a substrate, which may be a flexible material or a rigid material. The substrate may be selected from any material conventionally used in the art without limitation, for example, from polyvinyl alcohol, polyethylene, polyvinyl chloride, polytetrafluoroethylene, polyethylene terephthalate, polyurethane, polyamide, polyimide, polyesteramide, or polyetherimide.
In the present invention, the organic light-emitting portion includes a plurality of organic layers such as a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, an electron transport layer, and an electron injection layer.
Each layer of the light-emitting functional layer portion is selected from corresponding functional layers conventionally used in the art, without any limitation.
The material of the light-emitting layer is a material that can emit visible light by receiving holes and electrons from the hole-transporting layer and the electron-transporting layer, respectively, and combining the received holes and electrons, and is preferably a material having high quantum efficiency for fluorescence and phosphorescence. The light emitting materials are classified into blue, green and red light emitting materials according to their light emitting colors, and further into yellow and orange light emitting materials in order to realize more natural colors. Specific examples thereof include metal complexes of hydroxyquinoline derivatives, various metal complexes, anthracene derivatives, bisstyrylbenzene derivatives, pyrene derivatives, oxazole derivatives and polyparaphenylethaneAlkene derivatives, and the like, but are not limited thereto. In addition, the light emitting layer may include a host material and a guest material. As the host material and guest material of the light-emitting layer of the organic electroluminescent device of the present invention, light-emitting layer materials for organic electroluminescent devices known in the art may be used, and the host material may be, for example, thiazole derivatives, benzimidazole derivatives, polydialkylfluorene derivatives, or 4,4' -bis (9-Carbazolyl) Biphenyl (CBP); the guest material may be, for example, quinacridone, coumarin, rubrene, perylene and derivatives thereof, benzopyran derivatives, rhodamine derivatives or aminostyrene derivatives, Ir (ppy)3BH-1 and MQAB (95: 5).
In the light-emitting layer of the present invention, the ratio of the host material to the guest material used is 95:5 to 70:30, preferably 90:10 to 75:25, by mass.
In addition, the light emitting material may further include a phosphorescent or fluorescent material in order to improve fluorescent or phosphorescent characteristics. Specific examples of the phosphorescent material include phosphorescent materials of metal complexes of iridium, platinum, and the like. For example, Ir (ppy)3[ fac-tris (2-phenylpyridine) iridium]And the like, blue phosphorescent materials such as FIrpic and FIr6, and red phosphorescent materials such as Btp2Ir (acac). For the fluorescent material, those known in the art can be used.
In addition, in addition to the fluorescent or phosphorescent host-guest materials used as described above, a non-host-guest doping system material used for a light emitting layer in an organic electroluminescent device, a host-guest material having a Thermally Activated Delayed Fluorescence (TADF) function, and a form in which a TADF functional material and the above-described fluorescent or phosphorescent materials are combined and matched with each other, which are well known in the art, may be used.
The thickness of the light-emitting layer of the present invention may be 20 to 60nm, preferably 30 to 60 nm.
In one embodiment of the present invention, the light emitting layer is a host-guest coordination structure, wherein the host-guest structure is any structure conventionally selected in the art, preferably a single host + guest, such as a host material CBP and a guest dopant material ir (pq)2acac (weight ratio of 95:5), or a host material CBP and a guest dopant material GD19 (weight ratio of 95: 5).
In the present invention, the hole blocking layer is a layer that blocks holes injected from the anode from passing through the light emitting layer to the cathode, thereby extending the lifetime of the device and improving the performance of the device. The hole blocking layer of the present invention may be disposed over the light emitting layer. As the hole-blocking layer material of the organic electroluminescent device of the present invention, compounds having a hole-blocking effect commonly known in the art, for example, phenanthroline derivatives such as bathocuproine (referred to as BCP), metal complexes of hydroxyquinoline derivatives such as aluminum (III) bis (2-methyl-8-quinoline) -4-phenylphenolate (BAlq), various rare earth complexes, oxazole derivatives, triazole derivatives, triazine derivatives, and the like can be used. The hole blocking layer of the present invention may have a thickness of 2 to 200 nm.
The electron transport layer material is a material that easily receives electrons of the cathode and transfers the received electrons to the light emitting layer. Materials with high electron mobility are preferred. As the electron transport layer of the organic electroluminescent device of the present invention, electron transport layer materials for organic electroluminescent devices known in the art, for example, TPBI, tris (8-hydroxyquinoline) aluminum (Alq), may be used3) Metal complexes of hydroxyquinoline derivatives represented by 2-methyl-8-hydroxyquinoline p-hydroxydiphenoylaluminum (BAlq), various metal complexes, triazole derivatives, triazine derivatives, oxadiazole derivatives, thiadiazole derivatives, carbodiimide derivatives, quinoxaline derivatives, phenanthroline derivatives, silicon-based compound derivatives, and the like. The thickness of the electron transport layer of the present invention may be 20 to 80nm, preferably 30 to 60 nm.
The electron injection layer material is generally a material preferably having a low work function so that electrons are easily injected into the organic functional material layer. As the electron injection layer material of the organic electroluminescent device of the present invention, an electron injection layer material used in an organic electroluminescent device, which is known in the art, can be used, and examples thereof include alkali metal salts such as lithium fluoride (LiF) and cesium fluoride, alkaline earth metal salts such as magnesium fluoride, and metal oxides such as aluminum oxide. The thickness of the electron injection layer of the present invention may be 0.1 to 5nm, preferably 1 to 5 nm.
The electron transport layer material is, for example, TPBI. The electron transport layer material and the electron injection layer material may also be realized in the form of one layer, for example, by mixing specific materials to form the electron transport injection layer, such as TPBI and LiQ, for example, by mixing and evaporating the two materials in a mass ratio of 1: 1.
In the present invention, the hole transport region includes a hole transport layer, an electron blocking layer, and a hole injection layer, but is not limited thereto.
In general, an organic material having a p-type property, which is easily oxidized and electrochemically stable when it is oxidized, is mainly used as a hole injection material or a hole transport material. Meanwhile, an organic material having n-type properties, which is easily reduced and electrochemically stable when reduced, is used as an electron injection material or an electron transport material. As the light emitting layer material, a material having both p-type and n-type properties, which is stable when it is oxidized and reduced, is preferable, and a material having a higher light emitting efficiency for converting excitons into light when the excitons are formed is also preferable.
The material of the hole injection layer is generally a material preferably having a high work function so that holes are easily injected into the organic material layer. Specific examples of the material of the hole injection layer include, but are not limited to, molybdenum trioxide, HAT-CN, copper phthalocyanine, N '-diphenyl-N, N' -bis- [4- (phenyl-m-tolylamino) -phenyl ] -biphenyl-4, 4 '-diamine (DNTPD), 4', 4 ″ -tris (3-methylphenylphenylamino) triphenylamine (m-MTDATA), 4 '4 ″ -tris (N, N-diphenylamino) triphenylamine (TDATA), 4', 4 ″ -tris { N, - (2-naphthyl) -N-phenylamino } -triphenylamine (2TNATA), poly (3, 4-ethylenedioxythiophene)/poly (4-styrenesulfonate) (PEDOT/PSS), Polyaniline/dodecylbenzene sulfonic acid (PANI/DBSA), polyaniline/camphorsulfonic acid (PANI/CSA), or (polyaniline)/poly (4-styrenesulfonate) (PANI/PSS). The thickness of the hole injection layer of the present invention may be 1 to 40nm, preferably 5 to 20 nm.
The material of the hole transport layer is preferably a material having a high hole mobility, which enables holes to be transferred from the anode or the hole injection layer to the light-emitting layer. Specific examples of the material of the hole transport layer include, but are not limited to: carbazole-based derivatives such as N-phenylcarbazole or polyvinylcarbazole; a fluorene-based derivative; triphenylamine-based derivatives, such as N, N ' -bis (3-methylphenyl) -N, N ' -diphenyl- [1, 1-biphenyl ] -4, 4' -diamine (TPD) and 4,4', 4 ″ -tris (N-carbazolyl) triphenylamine (TCTA), N ' -bis (1-naphthyl) -N, N ' -diphenyl benzidine (NPB), 4' -cyclohexylidene bis [ N, N-bis (4-methylphenyl) aniline ] (TAPC). The thickness of the hole transport layer of the present invention may be 1 to 80nm, preferably 5 to 40 nm.
The hole injection layer and/or the hole transport layer may further include a charge generation material for improving conductivity. The charge generating material may be a p-dopant. Examples of non-limiting compounds of the P-dopant are, for example, quinone derivatives such as Tetracyanoquinodimethane (TCNQ) and 2,3,5, 6-tetrafluoro-tetracyano-1, 4-quinodimethane (F4-TCNQ); hexaazatriphenylene derivatives, such as 2,3,6,7,10, 11-hexacyano-1, 4,5,8,9, 12-hexaazatriphenylene (HAT-CN); cyclopropane derivatives, such as 4,4', 4 "- ((1E, 1' E, 1" E) -cyclopropane-1, 2, 3-trimethylenetri (cyanoformylidene)) tris (2,3,5, 6-tetrafluorobenzyl); metal oxides such as tungsten oxide and molybdenum oxide.
The material of the electron blocking layer is a material conventionally used in the art, and may be a fluorene-containing material, or a mixed material including a first organic material and a second organic material, wherein a ratio of the first organic material to the second organic material is 0.5:9.5-9.5:0.5 on a mass basis. The first organic material may be selected from compounds comprising one or more of fluorene, acridine or carbazole. The second organic material may be selected from compounds comprising one or more of azafluorene, triarylamine, or spiroxanthene fluorene.
The electron blocking layer of the present invention may have a thickness of 10 to 100nm, preferably 20 to 80 nm.
Abbreviations and structural formulae of materials used in the following examples are as follows:
in the invention, the device current efficiency/EQE/CIE data is tested by an IVL test system with the model number of FS-1000GA4 provided by Suzhou Franched scientific instruments and Co; the drive life data are tested by a ZJLS-4 type OLED aging life tester.
Example 1 fabrication of internal light extraction Structure
Spin-coating a layer of PHPS mixture (xylene as solvent and TiO as scattering particles) containing 20 wt% on a substrate cleaned in advance at 1500rpm2The average grain diameter is 200nm, and the weight is 15 wt% based on the solid content weight of perhydropolysilazane), then the mixture is placed in an oven at 100 ℃ for 15 minutes, the solvent is removed through precuring in the air atmosphere, and then the curing treatment is carried out for 120 minutes under the condition of ammonia water vapor, so as to form a scattering layer; on the scattering layer formed, a mixed solution containing 20 wt% of PHPS (xylene as solvent and TiO as nanoparticles) is spin-coated at a high rotation speed (e.g., 2000rpm)2Average particle diameter of 8nm, based on the weight of the solid content of perhydropolysilazane, of 15 wt%), and then placed in an oven at 100 ℃ for 15 minutes to be subjected to precuring in an air atmosphere to remove the solvent, and then to curing treatment for 120 minutes under the condition of ammonia steam to form an internal light extraction structure.
EXAMPLE 2 fabrication of blue light device
Molybdenum trioxide MoO with a film thickness of 10nm was deposited on a glass substrate having a transparent electrode of ITO with a thickness of 150nm by a vacuum deposition apparatus3As a hole injection layer; followed by evaporation of 140nm thick TAPC as a hole transport layer.
After the evaporation of the hole transport material is finished, a light-emitting layer of the OLED light-emitting device is manufactured, and the structure of the OLED light-emitting device comprises that BH-1 used by the OLED light-emitting layer is used as a main material, MQAB is used as a doping material, the doping proportion of the doping material is 5% by weight, and the thickness of the light-emitting layer is 25 nm.
After the light-emitting layer was deposited, the electron transport layer was continuously vacuum-deposited with a film thickness of 40nm and a material of TPBI.
On the electron transport layer, a lithium fluoride (LiF) layer having a film thickness of 1nm was formed by a vacuum evaporation apparatus, and this layer was an electron injection layer.
On the electron injection layer, an aluminum (Al) layer having a thickness of 80nm was formed by a vacuum deposition apparatus, and this layer was used as a cathode reflective electrode layer.
After the OLED light emitting device was completed as described above, the anode and cathode were connected by a driving circuit, and the current efficiency of the device and the lifetime of the device were measured.
Example 3 fabrication of a blue light device incorporating an internal light extraction Structure
The above experiment was repeated with the glass substrate described above replaced with a substrate incorporating the internal light extraction structure of example 1, and the EQE (external quantum efficiency) was increased by 72%, see table 1.
TABLE 1
| Examples | Current efficiency (cd/A) | EQE(％) | CIE(x,y) | Driving Life LT90(h) | Color of light emission |
| Example 2 | 6.8 | 6.15 | 0.15,0.18 | 30 | Blue light |
| Example 3 | 11.7 | 10.58 | 0.15,0.18 | 52 | Blue light |
Description of the drawings: the test condition of the current efficiency/EQE/CIE of the device is that the current density is 10mA/cm2(ii) a The test condition for the drive life LT95 was 1000 nits.
EXAMPLE 4 fabrication of Green devices
Molybdenum trioxide MoO with a film thickness of 10nm was deposited on a glass substrate having a transparent electrode of ITO with a thickness of 150nm by a vacuum deposition apparatus3As a hole injection layer; followed by evaporation of 140nm thick TAPC as a hole transport layer.
And after the evaporation of the hole transport material is finished, a light-emitting layer of the OLED light-emitting device is manufactured, and the structure of the light-emitting layer comprises CBP used as a main material of the OLED light-emitting layer, GD19 used as a doping material, the doping proportion of the doping material is 5% by weight, and the thickness of the light-emitting layer is 30 nm.
After the light-emitting layer was deposited, the electron transport layer was continuously vacuum-deposited with a film thickness of 40nm and a material of TPBI.
On the electron transport layer, a lithium fluoride (LiF) layer having a film thickness of 1nm was formed by a vacuum evaporation apparatus, and this layer was an electron injection layer.
On the electron injection layer, an aluminum (Al) layer having a film thickness of 80nm was formed by a vacuum deposition apparatus, and this layer was used as a cathode reflective electrode layer.
After the OLED light emitting device was completed as described above, the anode and cathode were connected by a driving circuit, and the current efficiency of the device and the lifetime of the device were measured.
Example 5 fabrication of a Green light device incorporating an internal light extraction Structure
The above experiment was repeated with the glass substrate replaced with a substrate incorporating the internal light extraction structure of example 1, and the EQE increased by 68%, see table 2.
TABLE 2
| Examples | Current efficiency (cd/A) | EQE(％) | CIE(x,y) | Driving Life LT95(h) | Color of light emission |
| Example 4 | 6.5 | 5.91 | 0.32,0.61 | 3.8 | Green light |
| Example 5 | 10.9 | 9.93 | 0.32,0.60 | 6.5 | Green light |
The device current efficiency/EQE/CIE test condition is that the current density is 10mA/cm2(ii) a The test condition for the drive life LT95 was 5000 nits.
EXAMPLE 6 fabrication of Red light device
Molybdenum trioxide MoO with a film thickness of 10nm was deposited on a glass substrate having a transparent electrode of ITO with a thickness of 150nm by a vacuum deposition apparatus3As a hole injection layer; followed by evaporation to a thickness of 140nmThe TAPC of (1) as a hole transport layer.
After the evaporation of the hole transport material is finished, the light-emitting layer of the OLED light-emitting device is manufactured, and the structure of the light-emitting layer comprises CBP used as a main material of the OLED light-emitting layer, Ir (pq)2acac is used as a doping material, the doping proportion of the doping material is 5 percent by weight, and the thickness of the luminescent layer is 30 nm.
After the light-emitting layer was deposited, the electron transport layer was continuously vacuum-deposited with a film thickness of 40nm and a material of TPBI.
On the electron transport layer, a lithium fluoride (LiF) layer having a film thickness of 1nm was formed by a vacuum evaporation apparatus, and this layer was an electron injection layer.
On the electron injection layer, an aluminum (Al) layer having a film thickness of 80nm was formed by a vacuum deposition apparatus, and this layer was used as a cathode reflective electrode layer.
After the OLED light emitting device was completed as described above, the anode and cathode were connected by a driving circuit, and the current efficiency of the device and the lifetime of the device were measured.
Example 7 fabrication of a Red light device incorporating an internal light extraction Structure
The above experiment was repeated with the glass substrate replaced with a substrate incorporating the internal light extraction structure of example 1, and the EQE increased by 66%, see table 3.
TABLE 3
The device current efficiency/EQE/CIE test condition is that the current density is 10mA/cm2(ii) a The test condition of the driving life LT95 was 3000 nits.
The experimental data show that after the internal light extraction structure is used, non-radiative coupling is converted into radiation light, so that EQE is improved, heat accumulation in the device is reduced, electrical performance degradation of the device is reduced, and service life of the device is prolonged.
Claims (11)
1. An internal light extraction structure, said internal light extraction structure comprising: a scattering layer formed on the substrate and including scattering particles that scatter light within a matrix formed by curing perhydropolysilazane; and a planarization layer formed on the scattering layer to planarize an uneven surface and including a matrix formed by curing perhydropolysilazane and high refractive index nanoparticles dispersed therein.
2. The internal light extraction structure of claim 1, wherein the substrate is a light transmissive plastic substrate or a glass substrate, such as a flexible or rigid material selected from: polyether sulfone resin, polyethylene, polyvinyl chloride, polytetrafluoroethylene, polyethylene terephthalate, polyethylene naphthalate, polyurethane, polyamide, polyimide, polyesteramide, polyetherimide, cyclic olefin polymer, and glass, but is not limited thereto.
3. The internal light extraction structure according to claim 1, wherein the number average molecular weight of the perhydropolysilazane is 300-; the solvent of the perhydropolysilazane solution is selected from toluene, dichloromethane, tetrahydrofuran, xylene, n-hexane, n-pentane, esters or ethers.
4. The internal light extraction structure according to claim 3, wherein the perhydropolysilazane is used in an amount of 15 to 50 wt%, preferably 20 to 40 wt%, more preferably 20 to 30 wt%, based on the total weight of the perhydropolysilazane solution.
5. The internal light extraction structure of claim 1, wherein the scattering layer is prepared by a precursor derivative method, and the precursor is a perhydropolysilazane mixture containing scattering particles.
6. The scattering layer of the internal light extraction structure of claim 5, wherein the scattering particles are used in an amount of 5 to 70 wt%, preferably 10 to 60 wt%, more preferably 15 to 50 wt%, based on the weight of the solid content of the perhydropolysilazane solution in the scattering layer mixture;
the particle size of the scattering particles is 10-1000nm, preferably 50-800nm, more preferably 100-600 nm;
the scattering particles are inorganic or organic particles, and are, for example, one or more selected from titanium dioxide, silicon oxide, zirconium oxide, magnesium fluoride, aluminum oxide, polystyrene, acrylic resin, polyurethane, polytetrafluoroethylene, melamine resin, benzoguanamine resin, epoxy resin, and silicone resin.
The scattering particles are spherical, elliptical or amorphous in shape.
7. The internal light extraction structure of claim 1, wherein the planarization layer is prepared by a precursor derivation method, and the precursor is a perhydropolysilazane mixture containing high refractive index nanoparticles.
8. The planarizing layer of the internal light extraction structure of claim 7, wherein the high refractive index nanoparticles are used in an amount of 5 to 60 wt%, preferably 10 to 50 wt%, more preferably 15 to 45 wt%, based on the weight of the solid content of the perhydropolysilazane solution in the planarizing layer mixture;
the particle size of the high-refractive-index nano particles is 1-20nm, preferably 1-15 nm;
the high-refractive-index nano-particles are more than one selected from titanium dioxide, zirconium oxide, indium tin oxide, cerium oxide, cadmium oxide, aluminum oxide, manganese dioxide, zinc oxide, niobium pentoxide, tantalum pentoxide, chromium oxide, nickel oxide, lead oxide, tin oxide, copper oxide, molybdenum oxide, silicon, hafnium oxide, manganese oxide, calcium carbonate, silicon carbide, silicon nitride, aluminum nitride, silver sulfide, zinc sulfide, barium sulfide, calcium sulfide, cadmium sulfide, barium titanate, zirconium titanate, lead chromate or polymer particles.
9. An organic light-emitting device comprising the internal light extraction structure according to any one of claims 1 to 8, further comprising a first electrode, a second electrode, and an organic light-emitting portion, wherein the first electrode, the organic light-emitting portion, and the second electrode are disposed in this order on a planarization layer of the internal light extraction structure.
10. The method of manufacturing an internal light extraction structure according to any one of claims 1 to 8, comprising the steps of:
(1) mixing the scattering particles with a perhydropolysilazane solution to prepare a scattering layer mixed solution;
(2) coating the scattering layer mixed solution on a substrate;
(3) drying the coated scattering layer mixed solution;
(4) curing the dried scattering layer mixed solution to form a scattering layer;
(5) mixing the high-refractive-index nano particles with a perhydropolysilazane solution to prepare a planarization layer mixed solution;
(6) coating the planarization layer mixed solution on the scattering layer;
(7) drying the coated planarization layer mixed liquid;
(8) and curing the dried planarization layer mixed liquid to form a planarization layer.
11. The method of manufacturing an organic light emitting device according to claim 9, comprising the steps of:
(1) mixing the scattering particles with a perhydropolysilazane solution to prepare a scattering layer mixed solution;
(2) coating the scattering layer mixed solution on a substrate;
(3) drying the coated scattering layer mixed solution;
(4) curing the dried scattering layer mixed solution to form a scattering layer;
(5) mixing the high-refractive-index nano particles with a perhydropolysilazane solution to prepare a planarization layer mixed solution;
(6) coating the planarization layer mixed solution on the scattering layer;
(7) drying the coated planarization layer mixed liquid;
(8) curing the dried planarization layer mixed liquid to form a planarization layer;
(9) on the planarization layer of the internal light extraction structure, a first electrode, an organic light emitting portion, and a second electrode are sequentially constructed.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811379677 | 2018-11-20 | ||
| CN2018113796775 | 2018-11-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111200077A true CN111200077A (en) | 2020-05-26 |
Family
ID=70747242
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910013105.3A Withdrawn CN111200077A (en) | 2018-11-20 | 2019-01-07 | Internal light extraction structure, organic light emitting device comprising same and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111200077A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112363267A (en) * | 2020-11-02 | 2021-02-12 | 浙江天月科技有限公司 | Flexible light guide film and preparation method thereof |
-
2019
- 2019-01-07 CN CN201910013105.3A patent/CN111200077A/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112363267A (en) * | 2020-11-02 | 2021-02-12 | 浙江天月科技有限公司 | Flexible light guide film and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109980085B (en) | Organic electroluminescent device containing covering layer and application | |
| Zhao et al. | Approaches to high performance white organic light-emitting diodes for general lighting | |
| JP5710704B2 (en) | ORGANIC LIGHT EMITTING ELEMENT AND MANUFACTURING METHOD THEREOF | |
| EP2600431B1 (en) | Organic electronic device and method of manufacturing the same | |
| KR101065912B1 (en) | Stacked organic light emitting devices | |
| KR101688317B1 (en) | Organic light emitting diode having low operating voltage and method for fabricating the same | |
| CN111200076A (en) | Organic light emitting device having internal light extraction structure and method of fabricating the same | |
| CN105870347A (en) | Quantum dot light-emitting device, fabrication method thereof, display substrate and display device | |
| CN110492007B (en) | Acridine compound and application thereof in organic electroluminescent device | |
| CN105552245A (en) | Electroluminescent device, fabrication method thereof and display device | |
| US9401493B2 (en) | Organic electroluminescent element, method for manufacturing same, and organic electroluminescent display device | |
| KR102206694B1 (en) | Electroluminescence device | |
| CN111200075B (en) | Light extraction structure, organic light emitting device and preparation method thereof | |
| JP5458554B2 (en) | Organic electroluminescence device and display device | |
| JP2008300270A (en) | Light emitting element | |
| WO2014187084A1 (en) | Organic electroluminescent component and display device | |
| JP2011065943A (en) | Organic electroluminescent element | |
| TWI364840B (en) | Tandem organic light emitting device and method for assembling the same | |
| Xu et al. | Polymer Gating White Flexible Field‐Induced Lighting Device | |
| CN111200077A (en) | Internal light extraction structure, organic light emitting device comprising same and manufacturing method thereof | |
| US20160163987A1 (en) | Electro-optical device and the use thereof | |
| CN104183718A (en) | Organic light emission diode and preparation method thereof | |
| CN111755618B (en) | Organic electroluminescent device containing covering layer and application | |
| CN111200078A (en) | Light extraction structure for organic light emitting device and organic light emitting device including the same | |
| KR20210043213A (en) | Quantum dot light emitting diode and quantum dot light emitting display device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WW01 | Invention patent application withdrawn after publication | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20200526 |