Electron transport layer materials and quantum dot light emitting diodes

Abstract

The present application relates to a kind of electron transport layer material and quantum dot light emitting diode.Electron transport layer material includes inorganic nanoparticles and two-dimensional layered semiconductor material doped in inorganic nanoparticles, two-dimensional layered semiconductor material accounts for the mass fraction of electron transport layer material is 0.001%~20%.When electron transport layer is made by electron transport layer material using the technical scheme of the present application, because two-dimensional layered semiconductor material in the above content range is doped in inorganic nanoparticles, the Fermi level of electron transport layer can be changed, the work function of electron transport layer is adjusted, so as to reduce the energy barrier between electron transport layer and quantum dot light emitting layer, relieve the interface charge accumulation between electron transport layer and quantum dot light emitting layer, improve device performance, and be conducive to wide application.In addition, the present application also relates to a kind of quantum dot light emitting diode, and the quantum dot light emitting diode includes electron transport layer, and the electron transport layer includes any of the above electron transport layer material.

Description

Technical Field

[0001] This invention relates to the field of light-emitting device technology, and in particular to an electron transport layer material and a quantum dot light-emitting diode. Background Technology

[0002] Quantum dots are semiconductor nanostructures in which excitons are bound together in three spatial directions. Due to their unique optical properties, such as continuously tunable emission wavelength with size and composition, narrow emission spectrum, high fluorescence efficiency, and good stability, quantum dot-based light-emitting diodes (QLEDs) have attracted widespread attention and research in the display field. Furthermore, QLED displays offer many advantages that LCDs cannot achieve, including wide viewing angles, high contrast, fast response times, and flexibility, thus holding promise as the next generation of display technology.

[0003] Commonly used quantum dot light-emitting diodes (QLEDs) typically employ an organic-inorganic hybrid structure. The electron transport layer (ETL) usually utilizes inorganic nanoparticles with high electron mobility, such as ZnO, resulting in electron mobility being much greater than hole mobility. In other words, the injection and transport capabilities of electrons are far greater than those of holes. However, excessive electron injection leads to a large accumulation of charge at the QD / ETL interface, and exciton quenching causes a degradation in device performance. Summary of the Invention

[0004] Therefore, it is necessary to provide an electron transport layer material and a quantum dot light-emitting diode to address the issue of how to improve device performance.

[0005] An electron transport layer material, comprising inorganic nanoparticles and a two-dimensional layered semiconductor material doped in the inorganic nanoparticles, wherein the two-dimensional layered semiconductor material accounts for 0.001% to 20% of the mass fraction of the electron transport layer material.

[0006] When the electron transport layer material of the present invention is used to fabricate the electron transport layer, since the inorganic nanoparticles are doped with two-dimensional layered semiconductor materials within the above-mentioned content range, the Fermi level of the electron transport layer can be changed, the work function of the electron transport layer can be adjusted, thereby reducing the energy barrier between the electron transport layer and the quantum dot light-emitting layer, alleviating the accumulation of interface charge between the electron transport layer and the quantum dot light-emitting layer, improving device performance, and facilitating its wide application.

[0007] In one feasible implementation, the two-dimensional layered semiconductor material is selected from at least one of aniline-coated Si nanoparticles, transition metal sulfides, and transition metal selenides.

[0008] In one feasible implementation, the transition metal sulfide is selected from at least one of molybdenum disulfide and tungsten disulfide.

[0009] In one feasible implementation, the transition metal selenide is selected from at least one of tungsten diselenide and indium selenide.

[0010] In one feasible implementation, the two-dimensional layered semiconductor material accounts for 0.01% to 5% of the mass fraction of the electron transport layer material.

[0011] In one feasible implementation, the two-dimensional layered semiconductor material accounts for 0.01% to 0.5% of the mass fraction of the electron transport layer material.

[0012] In one feasible implementation, the inorganic nanoparticles comprise metal oxides.

[0013] In one feasible implementation, the metal oxide is selected from at least one of ZnO and ZnMgO.

[0014] A quantum dot light-emitting diode includes a quantum dot light-emitting layer and an electron transport layer located on one side of the quantum dot light-emitting layer, wherein the electron transport layer comprises any of the electron transport layer materials described above.

[0015] The aforementioned quantum dot light-emitting diode has a simple structure. Because its electron transport layer contains the electron transport layer material described in this invention, it can change the Fermi level of the electron transport layer and adjust the work function of the electron transport layer, thereby reducing the energy barrier between the electron transport layer and the quantum dot light-emitting layer, alleviating the accumulation of interface charge between the electron transport layer and the quantum dot light-emitting layer, and improving the device performance.

[0016] In one feasible implementation, the thickness of the electron transport layer is 5 nm to 100 nm. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a quantum dot light-emitting diode according to an embodiment of the present invention. Detailed Implementation

[0018] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0020] One embodiment of the electron transport layer material includes inorganic nanoparticles and a two-dimensional layered semiconductor material doped in the inorganic nanoparticles, wherein the two-dimensional layered semiconductor material accounts for 0.001% to 20% of the mass fraction of the electron transport layer material.

[0021] Inorganic nanoparticles refer to a class of materials that can be used as the host material for electron transport layers. The main function of two-dimensional layered semiconductor materials is to alter the Fermi level of the electron transport layer, adjust its work function, thereby reducing the energy barrier between the electron transport layer and the quantum dot emitting layer, alleviating interfacial charge accumulation, and improving device performance.

[0022] Based on the aforementioned embodiments, the two-dimensional layered semiconductor material is selected from at least one of aniline-coated Si nanoparticles (LCP), transition metal sulfides, and transition metal selenides. Aniline-coated Si nanoparticles, transition metal sulfides, and transition metal selenides are all two-dimensional layered semiconductor materials. The valence band top energy level of these materials can reach between 6 eV and 6.5 eV (i.e., greater than or equal to 6 eV and less than or equal to 6.5 eV), exhibiting excellent conductivity and stability. This allows them to alter the Fermi level of the electron transport layer, adjust the work function of the electron transport layer, thereby reducing the energy barrier between the electron transport layer and the quantum dot emitting layer, and alleviating the accumulation of interface charge between the electron transport layer and the quantum dot emitting layer.

[0023] Based on the aforementioned embodiments, the transition metal sulfide is selected from at least one of molybdenum disulfide (MoS2) and tungsten disulfide (WS2).

[0024] Based on the aforementioned embodiments, the transition metal selenide is selected from at least one of tungsten diselenide (WSe2) and indium selenide (In2Se3).

[0025] Based on the aforementioned embodiments, the mass fraction of the two-dimensional layered semiconductor material in the electron transport layer material is 0.01% to 5%. When the mass fraction of the two-dimensional layered semiconductor material in the electron transport layer material is 0.01% to 5%, electron injection and transport can be reduced, but electrons are still slightly more numerous than holes, which does not affect the charge balance of the QLED device.

[0026] Based on the aforementioned embodiments, the mass fraction of the two-dimensional layered semiconductor material in the electron transport layer material is 0.01% to 0.5%. At this point, the quantum dot light-emitting device using the electron transport layer material of this embodiment exhibits optimal external quantum efficiency and lifetime.

[0027] Based on the aforementioned embodiments, the inorganic nanoparticles include metal oxides. Metal oxides can be used as the host material for electron transport layers.

[0028] Based on the aforementioned embodiments, the metal oxide is selected from at least one of ZnO and ZnMgO. That is, the metal oxide can be ZnO, ZnMgO, or a mixture of the two.

[0029] When the electron transport layer material of the present invention is used to fabricate the electron transport layer, since the inorganic nanoparticles are doped with two-dimensional layered semiconductor materials within the above-mentioned content range, the Fermi level of the electron transport layer can be changed, the work function of the electron transport layer can be adjusted, thereby reducing the energy barrier between the electron transport layer and the quantum dot light-emitting layer, alleviating the accumulation of interface charge between the electron transport layer and the quantum dot light-emitting layer, improving device performance, and facilitating its wide application.

[0030] One embodiment of a quantum dot light-emitting diode includes a quantum dot light-emitting layer and an electron transport layer located on one side of the quantum dot light-emitting layer, wherein the electron transport layer includes any of the electron transport layer materials described above.

[0031] Based on the aforementioned implementation method, the thickness of the electron transport layer is 5nm to 100nm.

[0032] Furthermore, the quantum dot light-emitting diode also includes an anode, a hole injection layer, a hole transport layer, and a cathode. The quantum dot light-emitting layer is disposed between the anode and the cathode, the hole transport layer is disposed between the anode and the quantum dot light-emitting layer, the hole injection layer is disposed between the anode and the hole transport layer, and the electron transport layer is disposed between the quantum dot light-emitting layer and the cathode.

[0033] It should be noted that the quantum dot light-emitting diode of the present invention can be a positive structure or an inverted structure.

[0034] When the quantum dot light-emitting diode can be a positively oriented structure, please refer to Figure 1 One embodiment of the quantum dot light-emitting diode 100 includes an anode 110, a hole injection layer (HIL) 120, a hole transport layer (HTL) 130, a quantum dot light-emitting layer (QD) 140, an electron transport layer (ETL) 150 and a cathode 160 stacked sequentially.

[0035] The anode 110 is located below the hole transport layer 130, and the material of the anode 110 can be, for example, ITO or IZO.

[0036] The hole injection layer 120 can be made of a conductive polymer, such as PEDOT:PSS; or it can be an n-type semiconductor with a high work function, such as HAT-CN, MoO3, WO3, V2O5, Rb2O, etc. It is understood that the hole injection layer 120 may not be provided.

[0037] The hole transport layer 130 is made of a semiconductor material, such as at least one selected from TFB, PVK, Poly-TPD, NPB, CBP, TCTA and NiO.

[0038] The quantum dot luminescent layer 140 is located above the hole transport layer 130. The material of the quantum dot luminescent layer 140 is selected from at least one of group II-VI compounds, group III-V compounds, group I-III-VI compounds, group IV elements, and perovskite quantum dots.

[0039] Among them, group II-VI compound semiconductors include, but are not limited to, ZnCdSeS, CdSe / ZnSe, CdSeS / CdS, CdSe / CdS / ZnS, ZnCdS / ZnS, and ZnCdSeS / ZnS. Group III-V compound semiconductors include, but are not limited to, InP and InP / ZnS. Group I-III-VI compound semiconductors include, but are not limited to, CuInS, AgInS, CuInS / ZnS, and AnInS / ZnS. Group IV elemental semiconductors include, but are not limited to, Si, C, and Graphene.

[0040] The electron transport layer 150 contains the electron transport layer material described in any embodiment of the present invention. The electron transport layer material includes inorganic nanoparticles and a two-dimensional layered semiconductor material doped in the inorganic nanoparticles. The two-dimensional layered semiconductor material accounts for 0.001% to 20% of the mass fraction of the electron transport layer material.

[0041] The cathode 160 is located above the electron transport layer 150, and the material of the cathode 160 can be, for example, Al or Ag.

[0042] Of course, the quantum dot light-emitting diode of the present invention is not limited to the above embodiments, and can also be an inverted structure.

[0043] When preparing the quantum dot light-emitting diode, the two-dimensional layered semiconductor material can be mixed into the ETL material first. After stirring and mixing evenly, a stable liquid is obtained. Then, device fabrication can begin by sequentially performing HIL spin coating, HTL spin coating, QD spin coating, ETL spin coating, and electrode evaporation to obtain the quantum dot light-emitting diode.

[0044] The aforementioned quantum dot light-emitting diode has a simple structure. Because its electron transport layer contains the electron transport layer material described in this invention, it can change the Fermi level of the electron transport layer and adjust the work function of the electron transport layer, thereby reducing the energy barrier between the electron transport layer and the quantum dot light-emitting layer, alleviating the accumulation of interface charge between the electron transport layer and the quantum dot light-emitting layer, and improving the device performance.

[0045] Referring to the above embodiments, in order to make the technical solution of the present invention more specific, clear and easy to understand, examples of the technical solution of the present invention are given below. However, it should be noted that the content to be protected by the present invention is not limited to the following embodiments.

[0046] Example 1

[0047] Step 1: Cleaning ITO anode conductive glass: Sonicate for 10 minutes each with deionized water, acetone, and isopropanol, dry with nitrogen, place in a petri dish, and treat with ozone for 20 minutes before use.

[0048] Step 2: Hole injection layer preparation: Dissolve 100 μL of the prepared HIL in ethyl benzoate solution and spin-coat it onto the anode at 3000 rpm for 30 seconds. Then anneal it under a 230℃ flat plate heating table for 30 min to obtain the hole injection layer.

[0049] Step 3: Hole transport layer preparation: Dissolve 100 μL of the prepared HTL in chlorobenzene solution and spin-coat it onto the hole injection layer at 3000 rpm for 30 seconds. Then anneal it under a 230℃ flat plate heating table for 30 min to obtain the hole transport layer.

[0050] Step 4: Quantum dot luminescent layer preparation: Dissolve 50 μL of the prepared HTL in n-octane solution and spin-coat it onto the hole transport layer at 3000 rpm for 30 seconds. Then anneal it under a 100°C flat plate heating stage for 5 min to obtain the quantum dot luminescent layer.

[0051] Step 5: Preparation of electron transport layer of doped layered material: Take 100 μL of ZnO ethanol solution mixed with 0.01% WS2 and spin-coat it onto the hole transport layer at 3000 rpm for 30 seconds. Then anneal it under a 100℃ flat plate heating stage for 5 min to obtain quantum dot light-emitting layer.

[0052] Step Six: Cathode Preparation: Evaporation of aluminum (Al) electrodes at 4 × 10⁻⁶ ℃. -4 A 100 nm thick cathode aluminum electrode was obtained by vapor deposition at Pa.

[0053] Example 2

[0054] Step 1: Cleaning ITO anode conductive glass: Sonicate for 10 minutes each with deionized water, acetone, and isopropanol, dry with nitrogen, place in a petri dish, and treat with ozone for 20 minutes before use.

[0055] Step 2: Hole injection layer preparation: Dissolve 100 μL of the prepared HIL in ethyl benzoate solution and spin-coat it onto the anode at 3000 rpm for 30 seconds. Then anneal it under a 230℃ flat plate heating table for 30 min to obtain the hole injection layer.

[0056] Step 3: Hole transport layer preparation: Dissolve 100 μL of the prepared HTL in chlorobenzene solution and spin-coat it onto the hole injection layer at 3000 rpm for 30 seconds. Then anneal it under a 230℃ flat plate heating table for 30 min to obtain the hole transport layer.

[0057] Step 4: Quantum dot luminescent layer preparation: Dissolve 50 μL of the prepared HTL in n-octane solution and spin-coat it onto the hole transport layer at 3000 rpm for 30 seconds. Then anneal it under a 100°C flat plate heating stage for 5 min to obtain the quantum dot luminescent layer.

[0058] Step 5: Preparation of electron transport layer of doped layered material: Take 100 μL of ZnO ethanol solution mixed with 0.05% WS2 and spin-coat it onto the hole transport layer at 3000 rpm for 30 seconds. Then place it under a 100℃ flat plate heating stage for annealing for 5 min to obtain quantum dot light-emitting layer.

[0059] Step Six: Cathode Preparation: Evaporation of aluminum (Al) electrodes at 4 × 10⁻⁶ ℃. -4 A 100 nm thick cathode aluminum electrode was obtained by vapor deposition at Pa.

[0060] Example 3

[0061] Step 1: Cleaning ITO anode conductive glass: Sonicate for 10 minutes each with deionized water, acetone, and isopropanol, dry with nitrogen, place in a petri dish, and treat with ozone for 20 minutes before use.

[0062] Step 2: Hole injection layer preparation: Dissolve 100 μL of the prepared HIL in ethyl benzoate solution and spin-coat it onto the anode at 3000 rpm for 30 seconds. Then anneal it under a 230℃ flat plate heating table for 30 min to obtain the hole injection layer.

[0063] Step 3: Hole transport layer preparation: Dissolve 100 μL of the prepared HTL in chlorobenzene solution and spin-coat it onto the hole injection layer at 3000 rpm for 30 seconds. Then anneal it under a 230℃ flat plate heating table for 30 min to obtain the hole transport layer.

[0064] Step 4: Quantum dot luminescent layer preparation: Dissolve 50 μL of the prepared HTL in n-octane solution and spin-coat it onto the hole transport layer at 3000 rpm for 30 seconds. Then anneal it under a 100°C flat plate heating stage for 5 min to obtain the quantum dot luminescent layer.

[0065] Step 5: Preparation of electron transport layer of doped layered material: Take 100 μL of ZnO ethanol solution mixed with 0.1% WS2 and spin-coat it onto the hole transport layer at 3000 rpm for 30 seconds. Then place it under a 100℃ flat plate heating stage for annealing for 5 min to obtain quantum dot light-emitting layer.

[0066] Step Six: Cathode Preparation: Evaporation of aluminum (Al) electrodes at 4 × 10⁻⁶ ℃. -4 A 100 nm thick cathode aluminum electrode was obtained by vapor deposition at Pa.

[0067] Example 4

[0068] Step 1: Cleaning ITO anode conductive glass: Sonicate for 10 minutes each with deionized water, acetone, and isopropanol, dry with nitrogen, place in a petri dish, and treat with ozone for 20 minutes before use.

[0069] Step 2: Hole injection layer preparation: Dissolve 100 μL of the prepared HIL in ethyl benzoate solution and spin-coat it onto the anode at 3000 rpm for 30 seconds. Then anneal it under a 230℃ flat plate heating table for 30 min to obtain the hole injection layer.

[0070] Step 3: Hole transport layer preparation: Dissolve 100 μL of the prepared HTL in chlorobenzene solution and spin-coat it onto the hole injection layer at 3000 rpm for 30 seconds. Then anneal it under a 230℃ flat plate heating table for 30 min to obtain the hole transport layer.

[0071] Step 4: Quantum dot luminescent layer preparation: Dissolve 50 μL of the prepared HTL in n-octane solution and spin-coat it onto the hole transport layer at 3000 rpm for 30 seconds. Then anneal it under a 100°C flat plate heating stage for 5 min to obtain the quantum dot luminescent layer.

[0072] Step 5: Preparation of electron transport layer of doped layered material: Take 100 μL of ZnO ethanol solution mixed with 0.5% WS2 and spin-coat it onto the hole transport layer at 3000 rpm for 30 seconds. Then place it under a 100℃ flat plate heating stage for annealing for 5 min to obtain quantum dot light-emitting layer.

[0073] Step Six: Cathode Preparation: Evaporation of aluminum (Al) electrodes at 4 × 10⁻⁶ ℃. -4 A 100 nm thick cathode aluminum electrode was obtained by vapor deposition at Pa.

[0074] Example 5

[0075] Step 1: Cleaning ITO anode conductive glass: Sonicate for 10 minutes each with deionized water, acetone, and isopropanol, dry with nitrogen, place in a petri dish, and treat with ozone for 20 minutes before use.

[0076] Step 2: Hole injection layer preparation: Dissolve 100 μL of the prepared HIL in ethyl benzoate solution and spin-coat it onto the anode at 3000 rpm for 30 seconds. Then anneal it under a 230℃ flat plate heating table for 30 min to obtain the hole injection layer.

[0077] Step 3: Hole transport layer preparation: Dissolve 100 μL of the prepared HTL in chlorobenzene solution and spin-coat it onto the hole injection layer at 3000 rpm for 30 seconds. Then anneal it under a 230℃ flat plate heating table for 30 min to obtain the hole transport layer.

[0078] Step 4: Quantum dot luminescent layer preparation: Dissolve 50 μL of the prepared HTL in n-octane solution and spin-coat it onto the hole transport layer at 3000 rpm for 30 seconds. Then anneal it under a 100°C flat plate heating stage for 5 min to obtain the quantum dot luminescent layer.

[0079] Step 5: Preparation of electron transport layer of doped layered material: Take 100 μL of ZnO ethanol solution mixed with 1% WS2 and spin-coat it onto the hole transport layer at 3000 rpm for 30 seconds. Then anneal it under a 100℃ flat plate heating stage for 5 min to obtain quantum dot light-emitting layer.

[0080] Step Six: Cathode Preparation: Evaporation of aluminum (Al) electrodes at 4 × 10⁻⁶ ℃. -4 A 100 nm thick cathode aluminum electrode was obtained by vapor deposition at Pa.

[0081] Example 6

[0082] Step 1: Cleaning ITO anode conductive glass: Sonicate for 10 minutes each with deionized water, acetone, and isopropanol, dry with nitrogen, place in a petri dish, and treat with ozone for 20 minutes before use.

[0083] Step 2: Hole injection layer preparation: Dissolve 100 μL of the prepared HIL in ethyl benzoate solution and spin-coat it onto the anode at 3000 rpm for 30 seconds. Then anneal it under a 230℃ flat plate heating table for 30 min to obtain the hole injection layer.

[0084] Step 3: Hole transport layer preparation: Dissolve 100 μL of the prepared HTL in chlorobenzene solution and spin-coat it onto the hole injection layer at 3000 rpm for 30 seconds. Then anneal it under a 230℃ flat plate heating table for 30 min to obtain the hole transport layer.

[0085] Step 4: Quantum dot luminescent layer preparation: Dissolve 50 μL of the prepared HTL in n-octane solution and spin-coat it onto the hole transport layer at 3000 rpm for 30 seconds. Then anneal it under a 100°C flat plate heating stage for 5 min to obtain the quantum dot luminescent layer.

[0086] Step 5: Preparation of electron transport layer of doped layered material: Take 100 μL of ZnO ethanol solution mixed with 5% WS2 and spin-coat it onto the hole transport layer at 3000 rpm for 30 seconds. Then place it under a 100℃ flat plate heating stage for annealing for 5 min to obtain quantum dot light-emitting layer.

[0087] Step Six: Cathode Preparation: Evaporation of aluminum (Al) electrodes at 4 × 10⁻⁶ ℃. -4 A 100 nm thick cathode aluminum electrode was obtained by vapor deposition at Pa.

[0088] Example 7

[0089] Step 1: Cleaning ITO anode conductive glass: Sonicate for 10 minutes each with deionized water, acetone, and isopropanol, dry with nitrogen, place in a petri dish, and treat with ozone for 20 minutes before use.

[0090] Step 2: Hole injection layer preparation: Dissolve 100 μL of the prepared HIL in ethyl benzoate solution and spin-coat it onto the anode at 3000 rpm for 30 seconds. Then anneal it under a 230℃ flat plate heating table for 30 min to obtain the hole injection layer.

[0091] Step 3: Hole transport layer preparation: Dissolve 100 μL of the prepared HTL in chlorobenzene solution and spin-coat it onto the hole injection layer at 3000 rpm for 30 seconds. Then anneal it under a 230℃ flat plate heating table for 30 min to obtain the hole transport layer.

[0092] Step 4: Quantum dot luminescent layer preparation: Dissolve 50 μL of the prepared HTL in n-octane solution and spin-coat it onto the hole transport layer at 3000 rpm for 30 seconds. Then anneal it under a 100°C flat plate heating stage for 5 min to obtain the quantum dot luminescent layer.

[0093] Step 5: Preparation of electron transport layer of doped layered material: Take 100 μL of ZnO ethanol solution mixed with 10% WS2 and spin-coat it onto the hole transport layer at 3000 rpm for 30 seconds. Then place it under a 100℃ flat plate heating stage for annealing for 5 min to obtain quantum dot light-emitting layer.

[0094] Step Six: Cathode Preparation: Evaporation of aluminum (Al) electrodes at 4 × 10⁻⁶ ℃. -4 A 100 nm thick cathode aluminum electrode was obtained by vapor deposition at Pa.

[0095] Example 8

[0096] Step 1: Cleaning ITO anode conductive glass: Sonicate for 10 minutes each with deionized water, acetone, and isopropanol, dry with nitrogen, place in a petri dish, and treat with ozone for 20 minutes before use.

[0097] Step 2: Hole injection layer preparation: Dissolve 100 μL of the prepared HIL in ethyl benzoate solution and spin-coat it onto the anode at 3000 rpm for 30 seconds. Then anneal it under a 230℃ flat plate heating table for 30 min to obtain the hole injection layer.

[0098] Step 3: Hole transport layer preparation: Dissolve 100 μL of the prepared HTL in chlorobenzene solution and spin-coat it onto the hole injection layer at 3000 rpm for 30 seconds. Then anneal it under a 230℃ flat plate heating table for 30 min to obtain the hole transport layer.

[0099] Step 4: Quantum dot luminescent layer preparation: Dissolve 50 μL of the prepared HTL in n-octane solution and spin-coat it onto the hole transport layer at 3000 rpm for 30 seconds. Then anneal it under a 100°C flat plate heating stage for 5 min to obtain the quantum dot luminescent layer.

[0100] Step 5: Preparation of electron transport layer of doped layered material: Take 100 μL of ZnO ethanol solution mixed with 20% WS2 and spin-coat it onto the hole transport layer at 3000 rpm for 30 seconds. Then place it under a 100℃ flat plate heating stage for annealing for 5 min to obtain quantum dot light-emitting layer.

[0101] Step Six: Cathode Preparation: Evaporation of aluminum (Al) electrodes at 4 × 10⁻⁶ ℃. -4 A 100 nm thick cathode aluminum electrode was obtained by vapor deposition at Pa.

[0102] Comparative Example 1

[0103] Step 1: Cleaning ITO anode conductive glass: Sonicate for 10 minutes each with deionized water, acetone, and isopropanol, dry with nitrogen, place in a petri dish, and treat with ozone for 20 minutes before use.

[0104] Step 2: Hole injection layer preparation: Dissolve 100 μL of the prepared HIL in ethyl benzoate solution and spin-coat it onto the anode at 3000 rpm for 30 seconds. Then anneal it under a 230℃ flat plate heating table for 30 min to obtain the hole injection layer.

[0105] Step 3: Hole transport layer preparation: Dissolve 100 μL of the prepared HTL in chlorobenzene solution and spin-coat it onto the hole injection layer at 3000 rpm for 30 seconds. Then anneal it under a 230℃ flat plate heating table for 30 min to obtain the hole transport layer.

[0106] Step 4: Quantum dot luminescent layer preparation: Dissolve 50 μL of the prepared HTL in n-octane solution and spin-coat it onto the hole transport layer at 3000 rpm for 30 seconds. Then anneal it under a 100°C flat plate heating stage for 5 min to obtain the quantum dot luminescent layer.

[0107] Step 5: Preparation of electron transport layer of doped layered material: Take 100 μL of ZnO ethanol solution and spin-coat it onto the hole transport layer at 3000 rpm for 30 seconds. Then anneal it under a 100℃ flat plate heating stage for 5 min to obtain quantum dot light-emitting layer.

[0108] Step Six: Cathode Preparation: Evaporation of aluminum (Al) electrodes at 4 × 10⁻⁶ ℃. -4 A 100 nm thick cathode aluminum electrode was obtained by vapor deposition at Pa.

[0109] Performance testing:

[0110] The EQE (external quantum efficiency) and lifetime of the QLEDs in Examples 1 to 8 and Comparative Example 1 were tested using the following methods, and the test data are shown in Table 1.

[0111] EQE test method: PR-655 spectrometer was used.

[0112] Lifetime testing method: Apply a constant current source to the QLED and record the brightness change curve over time; commonly used lifetime parameters include T. 95 This represents the time it takes for the brightness of a QLED to decay from its initial value to 95% of its initial value.

[0113] Table 1. Performance test results of QLEDs in Examples 1-8 and Comparative Example 1

[0114]

[0115] As can be seen from Table 1, compared with the QLED of Comparative Example 1, the QLEDs of Examples 1 to 8 of the present invention have better external quantum efficiency and lifetime, indicating that doping two-dimensional layered semiconductor materials into inorganic nanoparticles of the traditional electron transport layer can improve device performance.

[0116] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0117] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An electron transport layer material, characterized in that, In quantum dot light-emitting diodes, the electron transport layer material includes inorganic nanoparticles and a two-dimensional layered semiconductor material doped in the inorganic nanoparticles; The valence band top energy level of the two-dimensional layered semiconductor material in the inorganic nanoparticles reaches 6eV~6.5eV; The two-dimensional layered semiconductor material accounts for 0.01% to 0.5% of the mass fraction of the electron transport layer material; The inorganic nanoparticles include metal oxides; The two-dimensional layered semiconductor material is selected from at least one of transition metal sulfides and transition metal selenides; The metal oxide is selected from at least one of ZnO and ZnMgO.

2. The electron transport layer material according to claim 1, characterized in that, The transition metal sulfide is selected from at least one of molybdenum disulfide and tungsten disulfide.

3. The electron transport layer material according to claim 1, characterized in that, The transition metal selenide is selected from at least one of tungsten diselenide and indium selenide.

4. A quantum dot light-emitting diode, characterized in that, It includes a quantum dot light-emitting layer and an electron transport layer located on one side of the quantum dot light-emitting layer, wherein the electron transport layer comprises the electron transport layer material according to any one of claims 1 to 3.

5. The quantum dot light-emitting diode according to claim 4, characterized in that, The thickness of the electron transport layer is 5nm~100nm.

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