CN113540367A - Quantum dot light-emitting diode and preparation method thereof - Google Patents
Quantum dot light-emitting diode and preparation method thereof Download PDFInfo
- Publication number
- CN113540367A CN113540367A CN202010311261.0A CN202010311261A CN113540367A CN 113540367 A CN113540367 A CN 113540367A CN 202010311261 A CN202010311261 A CN 202010311261A CN 113540367 A CN113540367 A CN 113540367A
- Authority
- CN
- China
- Prior art keywords
- layer
- quantum dot
- hole transport
- dot light
- transport layer
- 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.)
- Granted
Links
- 239000002096 quantum dot Substances 0.000 title claims abstract description 103
- 238000002360 preparation method Methods 0.000 title claims abstract description 19
- 230000005525 hole transport Effects 0.000 claims abstract description 99
- 238000010521 absorption reaction Methods 0.000 claims abstract description 82
- 238000002347 injection Methods 0.000 claims abstract description 52
- 239000007924 injection Substances 0.000 claims abstract description 52
- 239000000463 material Substances 0.000 claims abstract description 41
- 239000000758 substrate Substances 0.000 claims description 29
- XMWRBQBLMFGWIX-UHFFFAOYSA-N C60 fullerene Chemical compound C12=C3C(C4=C56)=C7C8=C5C5=C9C%10=C6C6=C4C1=C1C4=C6C6=C%10C%10=C9C9=C%11C5=C8C5=C8C7=C3C3=C7C2=C1C1=C2C4=C6C4=C%10C6=C9C9=C%11C5=C5C8=C3C3=C7C1=C1C2=C4C6=C2C9=C5C3=C12 XMWRBQBLMFGWIX-UHFFFAOYSA-N 0.000 claims description 16
- 238000000034 method Methods 0.000 claims description 16
- 229910003472 fullerene Inorganic materials 0.000 claims description 15
- 238000004770 highest occupied molecular orbital Methods 0.000 claims description 9
- 238000004768 lowest unoccupied molecular orbital Methods 0.000 claims description 9
- 239000011358 absorbing material Substances 0.000 claims description 6
- 238000010030 laminating Methods 0.000 claims description 6
- 238000004519 manufacturing process Methods 0.000 claims description 6
- ATLMFJTZZPOKLC-UHFFFAOYSA-N C70 fullerene Chemical compound C12=C(C3=C4C5=C67)C8=C9C%10=C%11C%12=C%13C(C%14=C%15C%16=%17)=C%18C%19=C%20C%21=C%22C%23=C%24C%21=C%21C(C=%25%26)=C%20C%18=C%12C%26=C%10C8=C4C=%25C%21=C5C%24=C6C(C4=C56)=C%23C5=C5C%22=C%19C%14=C5C=%17C6=C5C6=C4C7=C3C1=C6C1=C5C%16=C3C%15=C%13C%11=C4C9=C2C1=C34 ATLMFJTZZPOKLC-UHFFFAOYSA-N 0.000 claims description 2
- 239000010410 layer Substances 0.000 description 242
- 238000004528 spin coating Methods 0.000 description 34
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 13
- 239000000243 solution Substances 0.000 description 13
- 238000010438 heat treatment Methods 0.000 description 10
- 239000011701 zinc Substances 0.000 description 8
- 230000005540 biological transmission Effects 0.000 description 7
- WEVYAHXRMPXWCK-UHFFFAOYSA-N Acetonitrile Chemical compound CC#N WEVYAHXRMPXWCK-UHFFFAOYSA-N 0.000 description 6
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 6
- 238000012360 testing method Methods 0.000 description 6
- 239000011787 zinc oxide Substances 0.000 description 6
- 238000000137 annealing Methods 0.000 description 5
- 239000002105 nanoparticle Substances 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- MVPPADPHJFYWMZ-UHFFFAOYSA-N chlorobenzene Chemical compound ClC1=CC=CC=C1 MVPPADPHJFYWMZ-UHFFFAOYSA-N 0.000 description 4
- 238000004140 cleaning Methods 0.000 description 4
- 239000000084 colloidal system Substances 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- TVMXDCGIABBOFY-UHFFFAOYSA-N octane Chemical compound CCCCCCCC TVMXDCGIABBOFY-UHFFFAOYSA-N 0.000 description 4
- 230000006798 recombination Effects 0.000 description 4
- 238000005215 recombination Methods 0.000 description 4
- 238000001035 drying Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 239000002346 layers by function Substances 0.000 description 3
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 238000000151 deposition Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000001704 evaporation Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- AMGQUBHHOARCQH-UHFFFAOYSA-N indium;oxotin Chemical compound [In].[Sn]=O AMGQUBHHOARCQH-UHFFFAOYSA-N 0.000 description 2
- 238000012858 packaging process Methods 0.000 description 2
- YBNMDCCMCLUHBL-UHFFFAOYSA-N (2,5-dioxopyrrolidin-1-yl) 4-pyren-1-ylbutanoate Chemical compound C=1C=C(C2=C34)C=CC3=CC=CC4=CC=C2C=1CCCC(=O)ON1C(=O)CCC1=O YBNMDCCMCLUHBL-UHFFFAOYSA-N 0.000 description 1
- AWXGSYPUMWKTBR-UHFFFAOYSA-N 4-carbazol-9-yl-n,n-bis(4-carbazol-9-ylphenyl)aniline Chemical compound C12=CC=CC=C2C2=CC=CC=C2N1C1=CC=C(N(C=2C=CC(=CC=2)N2C3=CC=CC=C3C3=CC=CC=C32)C=2C=CC(=CC=2)N2C3=CC=CC=C3C3=CC=CC=C32)C=C1 AWXGSYPUMWKTBR-UHFFFAOYSA-N 0.000 description 1
- 229910001316 Ag alloy Inorganic materials 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910004613 CdTe Inorganic materials 0.000 description 1
- 101000837344 Homo sapiens T-cell leukemia translocation-altered gene protein Proteins 0.000 description 1
- 229910000861 Mg alloy Inorganic materials 0.000 description 1
- 229920000144 PEDOT:PSS Polymers 0.000 description 1
- 229920001609 Poly(3,4-ethylenedioxythiophene) Polymers 0.000 description 1
- 102100028692 T-cell leukemia translocation-altered gene protein Human genes 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 229910052793 cadmium Inorganic materials 0.000 description 1
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 description 1
- UHYPYGJEEGLRJD-UHFFFAOYSA-N cadmium(2+);selenium(2-) Chemical compound [Se-2].[Cd+2] UHYPYGJEEGLRJD-UHFFFAOYSA-N 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 239000010406 cathode material Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000000295 emission spectrum Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000000695 excitation spectrum Methods 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- SBIBMFFZSBJNJF-UHFFFAOYSA-N selenium;zinc Chemical compound [Se]=[Zn] SBIBMFFZSBJNJF-UHFFFAOYSA-N 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 238000007738 vacuum evaporation Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
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
-
- 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
- H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
- H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
-
- 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
- H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
- H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
- H10K50/115—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers comprising active inorganic nanostructures, e.g. luminescent quantum dots
-
- 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
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K2101/00—Properties of the organic materials covered by group H10K85/00
- H10K2101/40—Interrelation of parameters between multiple constituent active layers or sublayers, e.g. HOMO values in adjacent layers
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/549—Organic PV cells
Landscapes
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Nanotechnology (AREA)
- Electroluminescent Light Sources (AREA)
Abstract
The invention belongs to the technical field of display, and particularly relates to a quantum dot light-emitting diode and a preparation method thereof. The quantum dot light-emitting diode comprises an anode, a cathode and a quantum dot light-emitting layer arranged between the anode and the cathode, wherein a hole transport layer is further arranged between the anode and the quantum dot light-emitting layer, an electron absorption layer is arranged between the hole transport layer and the anode, and the electron absorption layer contains a material capable of absorbing electrons. The electron absorption layer containing the material for absorbing electrons is arranged on one side of the hole transport layer close to the anode, so electrons are absorbed by the electron absorption layer at the interface of the hole transport layer and the electron absorption layer, and equivalent holes are generated in the hole transport layer, so that the carrier density in the hole transport layer is improved, the hole transport efficiency of the hole transport layer can be improved, the charge injection balance of the device is improved, and the luminous efficiency and the service life of the device are finally improved.
Description
Technical Field
The invention belongs to the technical field of display, and particularly relates to a quantum dot light-emitting diode and a preparation method thereof.
Background
The light emitting diode based on the quantum dot technology, namely, the quantum dot light emitting diode (QLED), has the advantages of high reliability, adjustable color, narrow half-peak width, high color gamut, high saturation, simple preparation and the like, and becomes the main development direction of the display technology in the future. In recent years, the QLED technology has significantly advanced, achieving a large span in efficiency and lifetime, where the performance of red and green devices has reached the requirements of the application, and blue devices have been making progress.
QLED devices were developed primarily from the experience of OLED devices, and have a large difference in charge injection from OLED devices due to the deep energy levels of inorganic quantum dot materials. By adopting the zinc oxide (ZnO) nanoparticles as the electron transport layer, the electron injection efficiency of the QLED device is greatly improved. However, the deep valence band energy level of the quantum dot results in a large hole injection barrier, which affects the hole injection efficiency, causes charge injection imbalance in the quantum dot layer, and greatly limits the efficiency and lifetime of the QLED device.
Therefore, the prior art is in need of improvement.
Disclosure of Invention
The invention aims to overcome the defects in the prior art, provides a quantum dot light-emitting diode and a preparation method thereof, and aims to solve the technical problem that the charge injection of the device is unbalanced due to low hole transmission efficiency of the conventional quantum dot light-emitting diode device.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a quantum dot light-emitting diode, which comprises an anode, a cathode and a quantum dot light-emitting layer arranged between the anode and the cathode, wherein a hole transport layer is also arranged between the anode and the quantum dot light-emitting layer, an electron absorption layer is arranged between the hole transport layer and the anode, and the electron absorption layer contains a material capable of absorbing electrons.
According to the quantum dot light-emitting diode provided by the invention, the electron absorption layer containing the material capable of absorbing electrons is arranged between the hole transport layer and the anode, so that electrons are absorbed by the electron absorption layer at the interface of the hole transport layer and the electron absorption layer, and after the electrons are absorbed by the electron absorption layer, equivalent holes can be generated in the hole transport layer at the same time, so that the carrier density in the hole transport layer is improved, the hole transport efficiency of the hole transport layer can be improved, the charge injection balance of the device is improved, and the luminous efficiency and the service life of the device are finally improved.
The invention also provides a preparation method of the quantum dot light-emitting diode, which comprises the following steps:
providing an anode substrate;
preparing an electron absorption layer containing a material capable of absorbing electrons on the anode substrate;
preparing a hole transport layer on the electron absorption layer;
sequentially laminating a quantum dot light-emitting layer and a cathode on the hole transport layer;
or,
providing a cathode substrate, and sequentially laminating a quantum dot light emitting layer and a hole transport layer on the cathode substrate;
preparing an electron absorption layer containing a material capable of absorbing electrons on the hole transport layer;
an anode is then prepared on the electron absorbing layer.
According to the preparation method of the quantum dot light-emitting diode, the electron absorption layer containing the material capable of absorbing electrons is prepared on the side, close to the anode, of the hole transport layer, and the electron absorption layer can improve the density of current carriers in the hole transport layer, so that the hole transport efficiency of the hole transport layer is improved, the charge injection balance of the device is improved, and therefore the finally obtained quantum dot light-emitting diode device has good luminous efficiency and service life.
Drawings
Fig. 1 is a schematic structural diagram of a quantum dot light emitting diode according to an embodiment of the invention;
fig. 2 is a schematic flow chart of a method for manufacturing a quantum dot light emitting diode according to an embodiment of the present invention;
fig. 3 is a schematic flow chart of a method for manufacturing a quantum dot light-emitting diode according to an embodiment of the present invention.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
On one hand, the embodiment of the invention provides a quantum dot light-emitting diode, which comprises an anode, a cathode and a quantum dot light-emitting layer arranged between the anode and the cathode, wherein a hole transport layer is also arranged between the anode and the quantum dot light-emitting layer, an electron absorption layer is arranged between the hole transport layer and the anode, and the electron absorption layer contains a material capable of absorbing electrons.
According to the quantum dot light-emitting diode provided by the embodiment of the invention, the electron absorption layer containing the material capable of absorbing electrons is arranged between the hole transport layer and the anode, so that electrons are absorbed by the electron absorption layer at the interface of the hole transport layer and the electron absorption layer, and after the electrons are absorbed by the electron absorption layer, equivalent holes can be generated in the hole transport layer at the same time, so that the carrier density in the hole transport layer is improved, the hole transport efficiency of the hole transport layer can be improved, the charge injection balance of the device is improved, and the luminous efficiency and the service life of the device are finally improved.
In one embodiment, the electron-absorbing layer is disposed on a surface of the hole-transporting layer proximate to the anode.
In one embodiment, the electron absorbing layer is comprised of the material capable of absorbing electrons. Further, the thickness of the electron absorption layer is 4-8 nm. The thickness range has better effect on improving the charge injection balance of the device.
In one embodiment, the LUMO level of the material capable of absorbing electrons is lower than or equal to the HOMO level of the hole transport layer, and under the condition, electrons at the HOMO level of the hole transport layer can spontaneously migrate to the LUMO level of the electron absorption layer, so that an equal amount of holes are generated in the hole transport layer, thereby increasing the carrier concentration of the hole transport layer and further increasing the hole transport efficiency of the hole transport layer.
In one embodiment, a hole injection layer is disposed between the hole transport layer and the anode, and the electron absorption layer is between the hole injection layer and the hole transport layer. After the electrons are absorbed by the electron absorption layer, equivalent holes are generated in the hole transport layer, and meanwhile, the electrons in the electron absorption layer can be neutralized by the recombination with the holes in the hole injection layer, so that the holes can be continuously generated at the interface of the hole transport layer and the electron absorption layer; therefore, the electron absorption layer interposed between the hole injection layer and the hole transport layer can improve the hole transport efficiency well.
Further, the LUMO energy level of the material capable of absorbing electrons is lower than or equal to the HOMO energy level of the hole injection transport layer. Further, the LUMO level of the electron absorption layer is deeper than or at the same level as the HOMO level of the hole injection layer and the hole transport layer; under these conditions, the excess electrons in the electron-absorbing layer are neutralized with the holes from the hole-injecting layer, and remain electrically neutral, so that the electrons can be continuously absorbed from the hole-transporting layer.
In an embodiment of the present invention, the material capable of absorbing electrons is selected from fullerene C60And fullerene C70At least one of (1). Fullerene C60And fullerene C70Is a hollow molecule composed of carbon, and has good electron absorption capacity. The LUMO energy level of the electron absorption layer composed of the materials is deeper than the HOMO energy levels of the hole injection layer and the hole transport layer or is at the same level, so that electrons can be better absorbed by the electron absorption layer at the interface of the hole transport layer and the electron absorption layer, and equivalent holes are generated in the hole transport layer, so that the carrier density in the hole transport layer is improved, and the hole transport efficiency of the hole transport layer is improved. Meanwhile, electrons in the electron absorption layer may be neutralized by recombination with holes in the hole injection layer, so that holes may be continuously generated at the interface of the hole transport layer and the electron absorption layer. The whole process greatly improves the hole transmission efficiency of the device, thereby improving the charge injection balance of the device, improving the efficiency and prolonging the service life of the device.
In one embodiment, an electron functional layer, such as an electron transport layer, or a stack of an electron injection layer and an electron transport layer, is disposed between the quantum dot light emitting layer and the cathode, wherein the electron injection layer is adjacent to the cathode.
The quantum dot light-emitting diode provided by the embodiment of the invention comprises an upright structure and an inverted structure. The quantum dot light emitting diode can be a top emitting device or a bottom emitting device.
In one embodiment, the front-mounted quantum dot light emitting diode comprises a laminated structure of an anode and a cathode which are oppositely arranged, a quantum dot light emitting layer arranged between the anode and the cathode, and a hole transport layer arranged between the anode and the quantum dot light emitting layer, wherein an electron absorption layer is arranged on the surface, close to the anode, of the hole transport layer, and the anode is arranged on a substrate. Further, a hole injection layer can be arranged between the anode and the electron absorption layer; an electron-transport layer, an electron-injection layer, a hole-blocking layer and other electron-functional layers can be arranged between the cathode and the quantum dot light-emitting layer. In some embodiments of the front structure device, the quantum dot light emitting diode includes a substrate, an anode disposed on a surface of the substrate, a hole injection layer disposed on a surface of the anode, an electron absorption layer disposed on a surface of the hole injection layer, a hole transport layer disposed on a surface of the electron absorption layer, a quantum dot light emitting layer disposed on a surface of the hole transport layer, an electron transport layer disposed on a surface of the quantum dot light emitting layer, and a cathode disposed on a surface of the electron transport layer.
In one embodiment, the inverted structure quantum dot light emitting diode comprises a laminated structure of an anode and a cathode which are oppositely arranged, a quantum dot light emitting layer arranged between the anode and the cathode, and a hole transport layer arranged between the anode and the quantum dot light emitting layer, wherein an electron absorption layer is arranged on the surface of the hole transport layer close to the anode, and the cathode is arranged on a substrate. Further, a hole injection layer can be arranged between the anode and the electron absorption layer; an electron-transport layer, an electron-injection layer, a hole-blocking layer and other electron-functional layers can be arranged between the cathode and the quantum dot light-emitting layer. In some embodiments of the device with an inverted structure, the quantum dot light emitting diode includes a substrate, a cathode disposed on a surface of the substrate, an electron transport layer disposed on a surface of the cathode, a quantum dot light emitting layer disposed on a surface of the electron transport layer, a hole transport layer disposed on a surface of the quantum dot light emitting layer, an electron absorbing layer disposed on a surface of the hole transport layer, a hole injection layer disposed on a surface of the electron absorbing layer, and an anode disposed on a surface of the hole injection layer.
The light-emitting quantum dots in the quantum dot light-emitting layer are oil-soluble quantum dots and comprise binary phase, ternary phase and quaternary phase quantum dots; wherein the binary phase quantum dots include CdS, CdSe, CdTe, InP, AgS, PbS, PbSe, HgS, etc., but are not limited thereto, and the ternary phase quantum dots include ZnXCd1-XS、CuXIn1-XS、ZnXCd1-XSe、ZnXSe1-XS、ZnXCd1-XTe、PbSeXS1-XEtc. are not limited thereto, and the quaternary phase quantum dots include, ZnXCd1-XS/ZnSe、CuXIn1-XS/ZnS、ZnXCd1-XSe/ZnS、CuInSeS、ZnXCd1-XTe/ZnS、PbSeXS1-Xthe/ZnS and the like are not limited thereto. Then the quantum dots can be any one of the three common red, green and blue quantum dots or other yellow light, and the quantum dots can be cadmium-containing or cadmium-free. The quantum dot light emitting layer of the material has the characteristics of wide and continuous excitation spectrum distribution, high emission spectrum stability and the like. The preparation of the quantum dot light emitting layer may include: and (3) spin-coating the prepared luminescent material solution with a certain concentration on a spin coater of a substrate on which the hole transport layer is spin-coated to form a film, controlling the thickness of the luminescent layer to be about 10-60 nm by adjusting the concentration of the solution, the spin-coating speed and the spin-coating time, and drying at a proper temperature.
The electron transport layer can be made of electron transport materials conventional in the art, including but not limited to ZnO, TiO2、CsF、LiF、CsCO3And Alq3One kind of (1). The preparation of the electron transport layer comprises: placing the substrate coated with the quantum dot light emitting layer in a vacuum evaporation chamber, evaporating an electron transmission layer with the thickness of about 80nm at the evaporation speed of about 0.01-0.5 nm/s, and annealing at a proper temperatureA fire. Or spin-coating an electron transport layer on the substrate with the quantum dot light-emitting layer in a glove box at 1000-5000 rpm and a thickness of about 30-80nm, and annealing at a proper temperature.
The hole transport layer may be made of a hole transport material conventional in the art, including but not limited to TFB, PVK, Poly-TPD, TCTA, PEDOT: PSS, CBP, etc., or any combination thereof, as well as other high performance hole transport materials. The preparation of the hole transport layer comprises: placing the substrate on a spin coater, and spin-coating the substrate with a prepared solution of a hole transport material to form a film; the film thickness is controlled by adjusting the concentration of the solution, the spin-coating speed and the spin-coating time, and then a thermal annealing process is performed at an appropriate temperature.
In one embodiment, a quantum dot light emitting diode has a structure as shown in fig. 1, which is, from bottom to top, an anode 1, a hole injection layer 2, an electron absorption layer 3, a hole transport layer 4, a quantum dot light emitting layer 5, an electron transport layer 6, and a cathode 7. Wherein, the anode can be an ITO electrode or an ITO/Ag/ITO electrode; the hole injection layer material can be PEDOT PPS; the electron absorption layer material may be fullerene C60Or fullerene C70(ii) a The hole transport layer material may be an inorganic hole transport metal oxide material; the electron transport layer material can be selected from zinc oxide; the cathode material may be Al, Ag or Mg/Ag alloys.
On the other hand, the embodiment of the invention also provides a preparation method of the quantum dot light-emitting diode,
specifically, as shown in fig. 2, a method for manufacturing a quantum dot light emitting diode with an inverted structure includes the following steps:
s01: providing an anode substrate;
s02: preparing an electron absorption layer containing a material capable of absorbing electrons on the anode substrate;
s03: preparing a hole transport layer on the electron absorption layer;
s04: sequentially laminating a quantum dot light-emitting layer and a cathode on the hole transport layer;
alternatively, as shown in fig. 3, the method for manufacturing the quantum dot light emitting diode with the inverted structure includes the following steps:
t01: providing a cathode substrate, and sequentially laminating a quantum dot light emitting layer and a hole transport layer on the cathode substrate;
t02: preparing an electron absorption layer containing a material capable of absorbing electrons on the hole transport layer;
t03: and preparing an anode on the electron absorption layer.
According to the two preparation methods of the quantum dot light-emitting diode provided by the embodiment of the invention, the electron absorption layer made of the material capable of absorbing electrons is prepared on one side of the hole transport layer close to the anode, and the absorption layer can improve the carrier density in the hole transport layer, so that the hole transport efficiency of the hole transport layer is improved, the charge injection balance of the device is improved, and the finally obtained quantum dot light-emitting diode device has good luminous efficiency and service life.
For the preparation method of the positive structure quantum dot light emitting diode, the selection of the material capable of absorbing electrons in the electron absorption layer in step S02 is described in detail above, and will not be further described here. The preparation of the electron absorption layer comprises the following steps: preparing a solution of the electron-absorbing material at a mass concentration of 1-5mg/ml (e.g., fullerene C)60Or fullerene C70Dissolving in acetonitrile at a concentration of 2mg/ml), and spin-coating on the anode for high-temperature drying (e.g., heating and drying at 180 deg.C for 10-20min at 120-.
Further, before the electron absorption layer containing the material capable of absorbing electrons is prepared on the anode substrate, the method also comprises the step of preparing a hole injection layer on the surface of the anode substrate. After the electrons are absorbed by the electron absorption layer, equivalent holes are generated in the hole transport layer, and meanwhile, the electrons in the electron absorption layer can be neutralized by the recombination with the holes in the hole injection layer, so that the holes can be continuously generated at the interface of the hole transport layer and the electron absorption layer; therefore, the electron absorption layer interposed between the hole injection layer and the hole transport layer can improve the hole transport efficiency well.
For theThe method for preparing the quantum dot light emitting diode with the inverted structure and the selection of the material capable of absorbing electrons in the electron absorption layer in the step T02 are described in detail above, and will not be further described here. The preparation of the electron absorption layer comprises the following steps: preparing a solution of the electron-absorbing material at a mass concentration of 1-5mg/ml (e.g., fullerene C)60Or fullerene C70Dissolved in acetonitrile at a concentration of 2mg/ml), and then spin-coated on the hole transport layer and dried at high temperature (e.g., dried by heating at 180 ℃ for 10-20min at 120 ℃).
Further, before the anode is prepared on the electron absorption layer, the method also comprises the step of preparing a hole injection layer on the surface of the electron absorption layer. After the electrons are absorbed by the electron absorption layer, equivalent holes are generated in the hole transport layer, and meanwhile, the electrons in the electron absorption layer can be neutralized by the recombination with the holes in the hole injection layer, so that the holes can be continuously generated at the interface of the hole transport layer and the electron absorption layer; therefore, the electron absorption layer interposed between the hole injection layer and the hole transport layer can improve the hole transport efficiency well.
Further, the obtained QLED is subjected to a packaging process, and the packaging process may be performed by a common machine or by a manual method. Preferably, the oxygen content and the water content in the packaging treatment environment are both lower than 0.1ppm so as to ensure the stability of the device.
The invention is described in further detail with reference to a part of the test results, which are described in detail below with reference to specific examples.
Example 1
A quantum dot light emitting diode, as shown in fig. 1, which comprises, from bottom to top: anode 1, hole injection layer 2, electron absorption layer 3, hole transport layer 4, quantum dot light emitting layer 5, electron transport layer 6, cathode 7. The preparation method of the quantum dot light-emitting diode comprises the following steps:
1. depositing ITO (indium tin oxide) with the thickness of 40nm on a transparent glass substrate to be used as an anode, cleaning the surface for 15 minutes by ultraviolet ozone (UVO), and cleaning the surface while changing the wettability of the surface;
2. PSS is used as a hole injection layer, the spin coating rotation speed is 5000 rpm, the spin coating is 40s, then the annealing is carried out for 15min at 150 ℃, and the whole step is carried out in the air;
3. spin coating a layer of fullerene C on the hole injection layer60Making an electron absorption layer: c60Dissolving in toluene to obtain a solution with a concentration of 2mg/ml, spin-coating (rotation speed of 5000 rpm, spin-coating for 30s) and heating at 80 deg.C for 10min, the whole process being carried out under N2In an atmosphere glove box;
4. spin-coating a layer of PVK on the electron absorption layer to serve as a hole transmission layer, dissolving the PVK in chlorobenzene, wherein the concentration of the solution is 8mg/ml, the spin-coating rotation speed is 3000 r/min, the spin-coating is carried out for 30s, then, heating is carried out for 15min at 150 ℃, and the step is carried out in a glove box;
5. a quantum dot light-emitting layer is spin-coated on the hole transport layer, a quantum dot colloid is dissolved in n-octane, the concentration is 10mg/ml, the spin-coating rotating speed is 2000 revolutions per minute, the spin-coating is carried out for 30s, then the heating is carried out for 10min at 100 ℃, and the step is carried out in a glove box;
6. and spin-coating zinc oxide nanoparticles on the quantum dot light-emitting layer to form an electron transmission layer, dissolving zinc oxide nanoparticle colloid in an ethanol solution, wherein the concentration is 30mg/ml, the spin-coating rotation speed is 3000 rpm, the spin-coating is carried out for 30 seconds, then, heating is carried out for 30min at 100 ℃, and the step is carried out in a glove box.
7. 100nmAg is evaporated on the electron transport layer to be used as a cathode.
Example 2
A quantum dot light emitting diode, as shown in fig. 1, which comprises, from bottom to top: anode 1, hole injection layer 2, electron absorption layer 3, hole transport layer 4, quantum dot light emitting layer 5, electron transport layer 6, cathode 7. The preparation method of the quantum dot light-emitting diode comprises the following steps:
1. depositing ITO (indium tin oxide) with the thickness of 40nm on a transparent glass substrate to be used as an anode, cleaning the surface for 15 minutes by ultraviolet ozone (UVO), and cleaning the surface while changing the wettability of the surface;
2. PSS is used as a hole injection layer, the spin coating rotation speed is 5000 rpm, the spin coating is 40s, then the annealing is carried out for 15min at 150 ℃, and the whole step is carried out in the air;
3. spin coating a layer of fullerene C on the hole injection layer70Making an electron absorption layer: c70Dissolving in toluene to obtain a solution with a concentration of 2mg/ml, spin-coating (rotation speed of 5000 rpm, spin-coating for 30s) and heating at 80 deg.C for 10min, the whole process being carried out under N2In an atmosphere glove box;
4. spin-coating a layer of PVK on the electron absorption layer to serve as a hole transmission layer, dissolving the PVK in chlorobenzene, wherein the concentration of the solution is 8mg/ml, the spin-coating rotation speed is 3000 r/min, the spin-coating is carried out for 30s, then, heating is carried out for 15min at 150 ℃, and the step is carried out in a glove box;
5. a quantum dot light-emitting layer is spin-coated on the hole transport layer, a quantum dot colloid is dissolved in n-octane, the concentration is 10mg/ml, the spin-coating rotating speed is 2000 revolutions per minute, the spin-coating is carried out for 30s, then the heating is carried out for 10min at 100 ℃, and the step is carried out in a glove box;
6. and spin-coating zinc oxide nanoparticles on the quantum dot light-emitting layer to form an electron transmission layer, dissolving zinc oxide nanoparticle colloid in an ethanol solution, wherein the concentration is 30mg/ml, the spin-coating rotation speed is 3000 rpm, the spin-coating is carried out for 30 seconds, then, heating is carried out for 30min at 100 ℃, and the step is carried out in a glove box.
7. 100nmAg is evaporated on the electron transport layer to be used as a cathode.
Comparative example
A quantum dot light emitting diode has the same structural materials and processes as those of example 1 except that no electron absorbing layer is provided.
Performance testing
The performance of the quantum dot light-emitting diode in the embodiment and the comparative example is tested, and the test indexes and the test method are as follows:
(1) external Quantum Efficiency (EQE): measured using an EQE optical test instrument. Note: the external quantum efficiency test is that the QLED device
The test results are shown in table 1 below:
TABLE 1
| Item group classification | External Quantum Efficiency (EQE)/(%) |
| Example 1 | 16.5％ |
| Example 2 | 14.3％ |
| Comparative example 1 | 8.5％ |
As can be seen from table 1 above, the external quantum efficiency of the quantum dot light emitting diode provided in the embodiment of the present invention (the electron absorption layer is inserted between the hole injection layer and the hole transport layer) is significantly higher than that of the quantum dot light emitting diode in the comparative example, which indicates that the quantum dot light emitting diode obtained in the embodiment has better light emitting efficiency.
It is noted that the embodiments provided by the present invention all use blue light quantum dots CdXZn1-XS/ZnS is used as a material of a luminescent layer, is based on that a blue light luminescent system uses more systems (the blue light quantum dot luminescent diode has more reference value because high efficiency is difficult to achieve), and does not represent that the invention is only used for the blue light luminescent system.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (10)
1. The quantum dot light-emitting diode comprises an anode, a cathode and a quantum dot light-emitting layer arranged between the anode and the cathode, wherein a hole transport layer is also arranged between the anode and the quantum dot light-emitting layer.
2. The quantum dot light-emitting diode of claim 1, wherein the electron-absorbing layer is composed of the electron-absorbing material; and/or the presence of a gas in the gas,
the LUMO energy level of the material capable of absorbing electrons is lower than or equal to the HOMO energy level of the hole transport layer.
3. The quantum dot light-emitting diode of claim 1, wherein the electron-absorbing material is selected from fullerene C60And fullerene C70At least one of; and/or the presence of a gas in the gas,
the thickness of the electron absorption layer is 4-8 nm.
4. The quantum dot light-emitting diode of claim 1, wherein the electron-absorbing layer is composed of at least one of fullerene C60 and fullerene C70.
5. The qd-led of any one of claims 1-4, wherein a hole injection layer is disposed between the hole transport layer and the anode, and the electron absorption layer is located between the hole injection layer and the hole transport layer.
6. The quantum dot light-emitting diode of claim 5, wherein the LUMO energy level of the electron-absorbing material is less than or equal to the HOMO energy level of the hole injection transport layer.
7. A preparation method of a quantum dot light-emitting diode is characterized by comprising the following steps:
providing an anode substrate;
preparing an electron absorption layer containing a material capable of absorbing electrons on the anode substrate;
preparing a hole transport layer on the electron absorption layer;
sequentially laminating a quantum dot light-emitting layer and a cathode on the hole transport layer;
or,
providing a cathode substrate, and sequentially laminating a quantum dot light emitting layer and a hole transport layer on the cathode substrate;
preparing an electron absorption layer containing a material capable of absorbing electrons on the hole transport layer;
and preparing an anode on the electron absorption layer.
8. The method of claim 7, wherein the LUMO level of the electron-absorbing material is lower than or equal to the HOMO level of the hole-transporting layer; and/or the presence of a gas in the gas,
the material capable of absorbing electrons is selected from fullerene C60And fullerene C70At least one of (1).
9. The method for manufacturing a quantum dot light-emitting diode according to claim 7 or 8, further comprising a step of preparing a hole injection layer on the surface of the anode substrate before preparing an electron absorption layer containing a material capable of absorbing electrons on the anode substrate; or,
before the anode is prepared on the electron absorption layer, the method also comprises the step of preparing a hole injection layer on the electron absorption layer.
10. The method of manufacturing a quantum dot light-emitting diode according to claim 9, wherein a LUMO energy level of the material capable of absorbing electrons is lower than or equal to a HOMO energy level of the hole injection transport layer; and/or the presence of a gas in the gas,
the electron absorption layer is composed of the material capable of absorbing electrons.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010311261.0A CN113540367B (en) | 2020-04-20 | 2020-04-20 | Quantum dot light emitting diode and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010311261.0A CN113540367B (en) | 2020-04-20 | 2020-04-20 | Quantum dot light emitting diode and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113540367A true CN113540367A (en) | 2021-10-22 |
| CN113540367B CN113540367B (en) | 2023-04-28 |
Family
ID=78093653
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010311261.0A Active CN113540367B (en) | 2020-04-20 | 2020-04-20 | Quantum dot light emitting diode and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113540367B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101281956A (en) * | 2007-04-05 | 2008-10-08 | 财团法人山形县产业技术振兴机构 | Organic electroluminescent device |
| CN102027614A (en) * | 2008-05-16 | 2011-04-20 | 株式会社半导体能源研究所 | Light-emitting element, light-emitting device, and electronic device |
| CN102067730A (en) * | 2008-05-16 | 2011-05-18 | Lg化学株式会社 | Stacked organic light-emitting diode |
| CN105140258A (en) * | 2014-06-06 | 2015-12-09 | 株式会社日本显示器 | Organic electroluminescent display device |
| CN106098957A (en) * | 2016-07-14 | 2016-11-09 | Tcl集团股份有限公司 | A kind of QLED and preparation method thereof |
| CN106920886A (en) * | 2016-04-26 | 2017-07-04 | 广东聚华印刷显示技术有限公司 | Organic electroluminescence device and preparation method thereof |
-
2020
- 2020-04-20 CN CN202010311261.0A patent/CN113540367B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101281956A (en) * | 2007-04-05 | 2008-10-08 | 财团法人山形县产业技术振兴机构 | Organic electroluminescent device |
| CN102027614A (en) * | 2008-05-16 | 2011-04-20 | 株式会社半导体能源研究所 | Light-emitting element, light-emitting device, and electronic device |
| CN102067730A (en) * | 2008-05-16 | 2011-05-18 | Lg化学株式会社 | Stacked organic light-emitting diode |
| CN105140258A (en) * | 2014-06-06 | 2015-12-09 | 株式会社日本显示器 | Organic electroluminescent display device |
| CN106920886A (en) * | 2016-04-26 | 2017-07-04 | 广东聚华印刷显示技术有限公司 | Organic electroluminescence device and preparation method thereof |
| CN106098957A (en) * | 2016-07-14 | 2016-11-09 | Tcl集团股份有限公司 | A kind of QLED and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113540367B (en) | 2023-04-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104681731B (en) | Perovskite type electroluminescent device and preparation method thereof | |
| JP5102967B2 (en) | Laminated body of PIN type organic light emitting diode and manufacturing method thereof | |
| WO2023273479A1 (en) | Organic electroluminescent device and display apparatus | |
| US20100033082A1 (en) | Method of Manufacture of a Multi-Layer Phosphorescent Organic Light Emitting Device, and Articles Thereof | |
| CN105552245A (en) | Electroluminescent device, fabrication method thereof and display device | |
| CN110010782B (en) | Quantum dot light-emitting layer, preparation method thereof and quantum dot device | |
| CN112909197B (en) | Super-fluorescent laminated device, preparation method thereof, display panel and display device | |
| CN107452886A (en) | A kind of laminated film and Organic Light Emitting Diode and preparation method thereof | |
| JP2008300270A (en) | Light emitting element | |
| CN111244298B (en) | Light-emitting device and display | |
| CN113540368A (en) | Composite material, preparation method thereof and quantum dot light-emitting diode | |
| CN108735910B (en) | pure inorganic perovskite light-emitting diode based on composite exciton recovery layer and preparation method thereof | |
| CN112467058B (en) | Ternary exciplex composite material main body and OLED device preparation method thereof | |
| CN211700337U (en) | Multilayer light-emitting quantum dot device | |
| CN111900258B (en) | Light-emitting device, quantum dot light-emitting diode and preparation method thereof | |
| WO2022011988A1 (en) | Nano material and preparation method therefor, and quantum dot light-emitting diode | |
| CN113540367A (en) | Quantum dot light-emitting diode and preparation method thereof | |
| CN111384247B (en) | Quantum dot light-emitting diode and preparation method thereof | |
| WO2024221660A1 (en) | Light-emitting device having high hole injection efficiency and manufacturing method therefor | |
| WO2022143737A1 (en) | Quantum dot light-emitting diode and preparation method therefor | |
| CN113130778A (en) | Quantum dot light-emitting diode and preparation method thereof | |
| WO2021136119A1 (en) | Quantum dot light emitting diode and preparation method therefor | |
| CN113594377A (en) | Quantum dot light-emitting diode and preparation method thereof | |
| KR101687637B1 (en) | White light-emitting device using the light-emitting layer and the color converting layer with a single quantum dot | |
| Du et al. | Design and assembly of an aqueous red CdTe QD-LED: major factors to fabricate aqueous QD-LEDs |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |