CN113044882B

CN113044882B - Nano material and preparation method thereof, and quantum dot light-emitting diode

Info

Publication number: CN113044882B
Application number: CN201911376456.7A
Authority: CN
Inventors: 何斯纳; 吴龙佳; 吴劲衡
Original assignee: TCL Technology Group Co Ltd
Current assignee: TCL Technology Group Co Ltd
Priority date: 2019-12-27
Filing date: 2019-12-27
Publication date: 2022-06-10
Anticipated expiration: 2039-12-27
Also published as: CN113044882A

Abstract

The invention provides a nano material, which comprises V₂O₅Nanoparticles and doping at V₂O₅S element and Zn element in the nanoparticle lattice. The nano material provided by the invention improves V₂O₅The p-type performance of the nano-particles improves the hole transmission capability, and when the nano-particles are used as a hole transmission layer material of a quantum dot light-emitting diode, the nano-particles can promote the effective recombination of electrons and holes in a light-emitting layer, reduce the influence of exciton accumulation on the performance of a light-emitting device and improve the display performance of the light-emitting device.

Description

Nano material and preparation method thereof, and quantum dot light-emitting diode

Technical Field

The invention belongs to the technical field of nano materials, and particularly relates to a nano material, a preparation method thereof and a quantum dot light-emitting diode.

Background

Semiconductor Quantum Dots (QDs) have quantum size effect, and people can realize the required luminescence with specific wavelength by regulating and controlling the size of the quantum dots, and the tuning range of the luminescence wavelength of the CdSe QDs can be from blue light to red light. In a conventional inorganic electroluminescent device, electrons and holes are injected from a cathode and an anode, respectively, and then recombined in a light emitting layer to form excitons for light emission.

In recent years, inorganic semiconductors have been studied as a hole transport layer with relative heat. Transition metal oxide (NiO, MoO)₃、WO₃、V₂O₅) The material has high work function and good environmental stability, so that the material attracts wide attention, is applied to photoelectric devices as an interface modification material, and prolongs the service life of the devices to a certain extent. Oxide of vanadium (V)₂O₅) With NiO and MoO₃、WO₃The same advantages such as high transmittance, good stability, solution processability and the like, due to V₂O₅The position of the conduction band of the material is the closest to the HOMO energy level of PEDOT and PSS, so that the material is easy to inject holes and is a hole transport material with good performance. However, with V₂O₅When used as a hole transport material for a light emitting diode, the hole transport property is to be improved in order to obtain good light emitting efficiency.

Disclosure of Invention

The invention aims to provide a nano material and a preparation method thereof, and aims to solve the problem of V₂O₅When the material is used as a hole transport material of a light emitting diode, the hole transport performance is to be improved.

Another object of the present invention is to provide a quantum dot light emitting diode containing the above nanomaterial.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a nanomaterial comprising V ₂O₅Nanoparticles and doped in V₂O₅S element and Zn element in the nanoparticle lattice.

The second aspect of the present invention provides a method for preparing a nanomaterial, comprising the steps of:

preparing an aqueous solution of a vanadium source, a sulfur source and a zinc source, adding protonic acid into the aqueous solution, and adjusting the pH of the aqueous solution to be less than or equal to 2; carrying out hydrothermal reaction at the temperature of not lower than 150 ℃ to prepare a nano material; the nano material is S, Zn co-doped V₂O₅Nanoparticles of V₂O₅Nanoparticles and doped in V₂O₅S element and Zn element in the nanoparticle lattice.

The invention provides a quantum dot light-emitting diode in a third aspect, which comprises a cathode and an anode which are oppositely arranged, a quantum dot light-emitting layer arranged between the cathode and the anode, and a hole transport layer arranged between the anode and the quantum dot light-emitting layer, wherein the material of the hole transport layer comprises V₂O₅Nanoparticles and doped in V₂O₅S element and Zn element in the nanoparticle lattice.

The nano material provided by the invention adopts an acceptor (S) -acceptor (Zn) co-doping mode to improve V₂O₅Thereby increasing the p-type property of₂O₅Hole transport capability of the nanomaterial of which the nanoparticles are the main body. In particular, group IIB elements Zn- Generation V₂O₅V in the nano-lattice has a shallow acceptor level such that V₂O₅The valence band conduction bands in the system all shift downward and form impurity levels at the fermi level, so that the doped system shows the property of p-type doping. When Zn is doped, the doped Zn atom is Zn²⁺In a solid solution mode, Zn²⁺Occupy V in the crystal lattice⁵⁺Two of the 2 valence electrons of Zn are combined with O to form saturated bonds, and oxygen vacancies are introduced, so that p-type V is improved₂O₅The hole carrier concentration of (2) improves the hole transport performance. At the same time, when S is doped, V₂S₃HOMO ratio V of₂O₅Deep, S replaces O to effectively reduce V₂O₅Thereby achieving an increase in acceptor level (and thus an increase in V)₂O₅P-type properties of). In addition, when S-Zn is co-doped, because of strong affinity among S-Zn, a gap acceptor defect is not easy to form in doping, and holes are easy to transmit, so that electrons and holes are promoted to be effectively compounded in a light-emitting layer, the influence of exciton accumulation on the performance of a light-emitting device is reduced, and the display performance of the light-emitting device is improved.

The preparation method of the nano material provided by the invention comprises the step of reacting a vanadium source, a sulfur source and a zinc source in a hydrothermal environment with the pH value of less than or equal to 2 to obtain the V-containing nano material ₂O₅Nanoparticles and doping at V₂O₅Nanoparticles of an S element and a Zn element in a nanoparticle lattice. The method is simple to operate, mild in condition, easy to control and beneficial to realizing large-scale preparation. More importantly, the nano material prepared by the method provided by the invention is prepared by the method at V₂O₅S element and Zn element are simultaneously doped in crystal lattice, so that V is effectively improved₂O₅The hole transport performance of the nano material can promote the effective recombination of electrons and holes in the quantum dot light-emitting layer when the nano material is used as a hole transport layer of the quantum dot light-emitting diode, and the light-emitting performance of the quantum dot light-emitting diode is improved.

The hole transport layer of the quantum dot light-emitting diode provided by the invention contains the S element and the Zn elementDoped V₂O₅And (3) nanoparticles. Due to the fact that at V₂O₅The crystal lattice is doped with S element and Zn element at the same time, which can effectively improve V₂O₅The hole transmission performance of the nano material can promote the effective recombination of electrons and holes in the quantum dot light-emitting layer when the nano material is used as a hole transmission layer of the quantum dot light-emitting diode, and the light-emitting performance of the quantum dot light-emitting diode is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the embodiments or drawings used in the prior art description, and obviously, the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a flow chart of a process for preparing a nanomaterial provided by an embodiment of the 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.

In the description of the present invention, it is to be understood that the terms "first", "second" and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

The weight of the related components mentioned in the description of the embodiments of the present invention may not only refer to the specific content of each component, but also represent the proportional relationship of the weight among the components, and therefore, it is within the scope of the disclosure of the description of the embodiments of the present invention to scale up or down the content of the related components according to the description of the embodiments of the present invention. Specifically, the weight described in the description of the embodiment of the present invention may be a unit of mass known in the chemical industry field, such as μ g, mg, g, and kg.

In a first aspect, embodiments of the present invention provide a nanomaterial comprising V₂O₅Nanoparticles and doping at V₂O₅S element and Zn element in the nanoparticle lattice.

According to the nano material provided by the embodiment of the invention, V is improved in a mode of acceptor (S) -acceptor (Zn) codoping₂O₅Thereby increasing the p-type property of₂O₅Hole transport capability of the nano material with the nano particles as the main body. In particular, group IIB elements Zn substitute for V₂O₅V in the nano-lattice has a shallow acceptor level such that V₂O₅The valence band conduction bands in the system all shift downward and form impurity levels at the fermi level, thereby enabling the doped system to exhibit p-type doping properties. When Zn is doped, the doped Zn atom is Zn²⁺In a solid solution manner, Zn²⁺Occupy V in the crystal lattice⁵⁺Two of the 2 valence electrons of Zn are combined with O to form saturated bonds, and oxygen vacancies are introduced, so that p-type V is improved₂O₅The hole carrier concentration of (2) improves the hole transport performance. At the same time, when S is doped, V₂S₃HOMO ratio V of₂O₅Deep, S replaces O to effectively reduce V₂O₅Thereby achieving an increase in acceptor level (and thus an increase in V)₂O₅P-type properties of (a). In addition, when S-Zn is co-doped, because of strong affinity among S-Zn, a gap acceptor defect is not easy to form in doping, and holes are easy to transmit, so that electrons and holes are promoted to be effectively compounded in a light-emitting layer, the influence of exciton accumulation on the performance of a light-emitting device is reduced, and the display performance of the light-emitting device is improved.

In some embodiments, the ratio of the molar amount of the V element to the sum of the molar amounts of the S element and the Zn element in the nanomaterial is 1:0.05 to 0.1. This applicationIn the embodiment, V and the doping element (S)^2-、Zn²⁺) The molar ratio of (A) mainly affects V₂O₅The degree of S, Zn co-doping in the nanoparticles, in turn, affects S, Zn co-doped V₂O₅Hole transport properties of the nanoparticles. In particular, when said S, Zn is co-doped with V₂O₅When the ratio of the molar weight of the V element to the sum of the molar weights of the S element and the Zn element in the nanoparticles is 1: 0.05-0.1, the doping amounts of the S element and the Zn element are appropriate, and the V can be reduced₂O₅The valence band conduction band of the nano-particles improves the acceptor level to achieve enhanced V₂O₅Purpose of nanoparticle p-type properties. If the S, Zn codoped V₂O₅In the nanoparticles, the doping amounts of the S element and the Zn element are too high, so that S, Zn co-doped V₂O₅The ratio of the sum of the molar amounts of the S element and the Zn element to the molar amount of the V element in the nanoparticles is more than 0.1:1, which causes V₂O₅Mutation of the lattice, formation of new lattices and formation of impurities, affecting V₂O₅The property of the body reduces the hollow transmission capability of the body. In particular, the S, Zn codoped V ₂O₅When the ratio of the sum of the molar amounts of the S element and the Zn element to the molar amount of the V element in the nanoparticles is more than 0.1:1, the S element and the Zn element are in the V state₂O₅The solid solubility in the nanoparticles reaches saturation, and excessive S element and Zn element are gathered in S, Zn co-doped V₂O₅The surface of the crystal grain forms a new phase, and the nanometer V is reduced₂O₅Thereby changing the bulk material V₂O₅The properties of the nanoparticles; at the same time, an excess of S^2-And Zn²⁺Also enter V₂O₅Causes expansion of the crystal lattice, and generates large distortion and strain energy of the crystal lattice. The S, Zn codoped V₂O₅In the nano particles, the doping amount of the S element and the Zn element is too low, so that S, Zn codoped V₂O₅The S-element in the nanoparticleWhen the ratio of the sum of the molar amounts of the element and the Zn element to the molar amount of the V element is less than 0.05:1, S, Zn is lost during the doping reaction, and thus effective doping cannot be achieved.

Further, since Zn element is responsible for adjusting V₂O₅Since the nanocrystal has a bond function due to an acceptor level, the doping amount of the Zn element is preferably higher than that of the S element. In some embodiments, the molar ratio of the S element to the Zn element in the nanomaterial is 1:2 to 3.

The nano material provided by the embodiment of the invention can be prepared by the following method.

As shown in fig. 1, a second aspect of the embodiments of the present invention provides a method for preparing a nanomaterial, including the following steps:

preparing an aqueous solution of a vanadium source, a sulfur source and a zinc source, adding protonic acid into the aqueous solution, and adjusting the pH of the aqueous solution to be less than or equal to 2; carrying out hydrothermal reaction at the temperature of not lower than 150 ℃ to prepare a nano material; the nano material comprises V₂O₅Nanoparticles and doped in V₂O₅S element and Zn element in the nanoparticle lattice.

According to the preparation method of the nano material provided by the embodiment of the invention, a vanadium source, a sulfur source and a zinc source react in a hydrothermal environment with the pH value of less than or equal to 2, so that S, Zn co-doped V can be prepared₂O₅And (3) nanoparticles. The method is simple to operate, mild in condition, easy to control and beneficial to realizing large-scale preparation. More importantly, the nano material prepared by the method provided by the embodiment of the invention is prepared by the method V₂O₅S element and Zn element are simultaneously doped in crystal lattices, so that V is effectively improved₂O₅The hole transport performance of the nano material can promote the effective recombination of electrons and holes in the quantum dot light-emitting layer when the nano material is used as a hole transport layer of the quantum dot light-emitting diode, and the light-emitting performance of the quantum dot light-emitting diode is improved.

Specifically, preparing an aqueous solution of a vanadium source, a sulfur source and a zinc source, wherein the vanadium source is used for providing preparation V₂O₅The V element required by the nano-particles, the sulfur source is used for providing doping to the V₂O₅S element in nanoparticles, the zinc source for providing doping to the V₂O₅Zn element in nanoparticles. Specifically, the vanadium source, the sulfur source and the zinc source are selected from the vanadium source, the sulfur source and the zinc source which have better solubility in a reaction solvent. In some embodiments, the vanadium source is selected from a soluble metavanadate salt that provides metavanadate ions to react with protic hydrogen to form HVO in a subsequent strong acid environment₃. In a specific embodiment, the vanadium source may be selected from, but not limited to, at least one of amine metavanadate, potassium metavanadate, and sodium metavanadate. In some embodiments, the sulfur source is selected from at least one of sodium sulfide, potassium sulfide, thiourea, amine sulfide. In some embodiments, the zinc source is selected from a soluble inorganic or organic zinc salt, including, but not limited to, at least one of zinc acetate, zinc nitrate, zinc chloride, zinc sulfate, zinc acetate dihydrate.

The method for preparing the aqueous solution of the vanadium source, the sulfur source and the zinc source is not strictly limited, and the aqueous solution of the vanadium source, the sulfur source and the zinc source can be prepared by firstly providing the vanadium source, the sulfur source and the zinc source and then dissolving the vanadium source, the sulfur source and the zinc source in water; or preparing one or two aqueous solutions of a vanadium source, a sulfur source and a zinc source, and then adding the rest raw materials. When aqueous solutions of two of a vanadium source, a sulfur source and a zinc source are prepared first, the adding sequence of the two metal sources is not strictly limited; when the remaining raw materials are added, the order of addition is not strictly limited when the remaining raw materials are two. It should be noted that in the examples of the present application, water was used as the dissolution solvent and reaction medium for the vanadium source, sulfur source and zinc source, because the present application produces V by hydrothermal reaction ₂O₅Nano particles and realizes that S element and Zn element are in V under the condition of hydrothermal reaction₂O₅Doping in the crystal lattice.

V ions and dopant ions (S) in the aqueous solution^2-、Zn²⁺) Molar ratio of (A) to the subsequently prepared S, Zn co-doped V₂O₅The p-type property of the nanoparticles has a large influenceFurther influencing the hole transport performance of the obtained nano material. In some embodiments, in the step of preparing the aqueous solution of a vanadium source, a sulfur source, and a zinc source, the aqueous solution of a vanadium source, a sulfur source, and a zinc source is prepared in such a manner that the ratio of the molar amount of the V element to the sum of the molar amounts of the S element and the Zn element is 1:0.05 to 0.1. In this case, the sulfur source and the zinc source are contained in appropriate amounts and can be sufficiently doped with V₂O₅In the nano-particle lattice, lowering V₂O₅The valence band conduction band of the nano-particles improves the acceptor level to achieve the enhancement of V₂O₅Purpose of nanoparticle p-type properties. If the addition amounts of the sulfur source and the zinc source are too high when preparing an aqueous solution of the vanadium source, the sulfur source and the zinc source, so that the ratio of the sum of the molar amounts of the S element and the Zn element to the molar amount of the V element in the aqueous solution is more than 0.1:1, V will be caused in the hydrothermal reaction process₂O₅Mutation of the lattice, formation of new lattices and formation of impurities, affecting V ₂O₅The property of the body reduces the hole transmission capability of the body. Specifically, when the ratio of the sum of the molar amounts of the S element and the Zn element to the molar amount of the V element is more than 0.1:1, S is contained in the alloy^2-And Zn²⁺At the V₂O₅The solid solubility in the nano particles reaches saturation, and when the doping amount continues to increase, excessive S^2-And Zn²⁺Will accumulate in the formed S, Zn codoped V₂O₅The surface of the crystal grain forms a new phase, and the nanometer V is reduced₂O₅Thereby changing the bulk material V₂O₅The properties of the nanoparticles; at the same time, an excess of S^2-And Zn²⁺Also enter V₂O₅Causes expansion of the crystal lattice, and generates large lattice distortion and strain energy. When an aqueous solution of a vanadium source, a sulfur source and a zinc source is prepared, the addition amounts of the sulfur source and the zinc source are too low, so that the ratio of the sum of the molar amounts of the S element and the Zn element to the molar amount of the V element in the aqueous solution is less than 0.05:1, and effective doping cannot be realized due to loss of the sulfur source and the zinc source in the hydrothermal reaction process.

Further preferred, since Zn element is responsible for adjusting V₂O₅Since the nanocrystal has a bond function due to an acceptor level, the doping amount of the Zn element is preferably higher than that of the S element. In some embodiments, in the step of preparing the aqueous solution of the vanadium source, the sulfur source and the zinc source, the aqueous solution of the vanadium source, the sulfur source and the zinc source is prepared according to a molar ratio of the S element to the Zn element of 1: 2-3.

In a specific preferred embodiment, in the step of preparing the aqueous solution of the vanadium source, the sulfur source and the zinc source, the aqueous solution of the vanadium source, the sulfur source and the zinc source is prepared according to the ratio of the molar amount of the V element to the sum of the molar amounts of the S element and the Zn element of 1: 0.05-0.1 and the molar ratio of the S element to the Zn element of 1: 2-3, so that V is₂O₅S in the nano lattice^2-And Zn²⁺The doping amount of (A) reaches an optimal level, so that S, Zn codoped V is obtained₂O₅The nanoparticles have excellent p-type properties.

In the embodiment of the application, in an aqueous solution of a vanadium source, a sulfur source and a zinc source, a protonic acid is added into the aqueous solution, and the protonic acid can provide active protons H⁺VO for providing with the vanadium source₃ ^-Reacting to produce HVO₃(ii) a At the same time, the acidic condition provided by the protonic acid promotes HVO₃Conversion to V₂O₅·H₂And O. Notably, in order to provide VO for supply with the vanadium source₃ ^-Proton of reaction H⁺And promote HVO₃Conversion to V₂O₅·H₂And O, when protonic acid is required to be added into the aqueous solution, adjusting the pH of the aqueous solution to be less than or equal to 2. If the pH in the aqueous solution is too high, above 2, due to protons H in the aqueous solution⁺Deficiency of H⁺And VO ₃ ^-Reaction to HVO₃And HVO₃Conversion to V₂O₅·H₂The reaction process of O tends to be slow, and the reaction time needs to be increased; the reaction time is increased, which easily results in large particles V₂O₅And (4) forming crystals. Large particle V₂O₅The hole transport property of the crystal is poor when S, Zn co-doped V₂O₅The nano particles contain large particles V₂O₅When crystalline, the hole transport properties of the nanomaterial may be reduced. More preferably, in the step of adjusting the pH of the aqueous solution, a protonic acid is added to the aqueous solution to adjust the pH of the aqueous solution to 1 or less. At this time, protons H in the aqueous solution⁺Is high in content and is favorable for promoting HVO₃To obtain more V₂O₅。

In some embodiments, the protic acid is selected from at least one of concentrated sulfuric acid, concentrated nitric acid, and concentrated hydrochloric acid. The concentrated sulfuric acid, the concentrated nitric acid and the concentrated hydrochloric acid have high-concentration H⁺Is favorable for increasing H in aqueous solution⁺Concentration, thereby promoting H⁺And VO₃ ^-Reaction to HVO₃And HVO₃Conversion to V₂O₅·H₂O。

After the pH value of the aqueous solution is adjusted, heating the aqueous solution to more than 150 ℃ for heating treatment, and reacting the vanadium source, the sulfur source and the zinc source under an acidic hydrothermal condition. Specifically, in one aspect, the VO provided by the vanadium source ₃ ^-With a high concentration of protons H in the aqueous solution⁺Binding, the following reaction occurs: (1) VO (vacuum vapor volume)₃ ^-+H⁺→HVO₃(aq)；(2)HVO₃(aq)→V₂O₅·H₂And O. It should be noted that during the hydrothermal reaction, H is present in the aqueous system⁺More and more favorable to HVO₃To obtain more V₂O₅. In another aspect, the Zn atom in the zinc source is Zn²⁺In a solid solution manner, Zn²⁺Occupy V₂O₅V in the crystal lattice⁵⁺Two of the 2 valence electrons of Zn are combined with O to form saturated bonds, and oxygen vacancies are introduced, so that p-type V is improved₂O₅Hole carrier concentration of (a); meanwhile, S provided by the sulfur source enters V₂O₅In the crystal lattice, instead of V₂O₅In (3) O, decreaseV₂O₅HOMO level of.

In some embodiments, the hydrothermal reaction is carried out at a temperature of 150 ℃ to 220 ℃ for 8 hours to 30 hours. At a reaction temperature of 150 ℃ to 220 ℃, H⁺And VO₃ ^-Reaction to HVO₃、HVO₃Conversion to V₂O₅·H₂Reaction of O, and S element and Zn²⁺At V₂O₅The doping reaction is mild and sufficient, and the V with uniform doping level can be obtained₂O₅And (3) nano materials. If the hydrothermal reaction time is increased to more than 30 hours, large particles V are liable to be formed₂O₅And (5) forming crystals.

Further, after the hydrothermal reaction is completed, the reaction system is cooled and washed, and then is subjected to a drying treatment. In some embodiments, the drying process is performed at a temperature of 50 ℃ to 60 ℃.

In a preferred embodiment, the preparation of the nanomaterial comprises the steps of: preparing an aqueous solution of a vanadium source, a sulfur source and a zinc source according to the ratio of the molar weight of a V element to the sum of the molar weights of an S element and a Zn element of 1: 0.05-0.1 and the ratio of the molar weight of the S element to the molar weight of the Zn element of 1: 2-3, adding a protonic acid into the aqueous solution, and adjusting the pH value of the aqueous solution to be less than or equal to 1; carrying out hydrothermal reaction at the temperature of 150-220 ℃ for 18-30 hours to prepare a nano material; the nano material is S, Zn co-doped V₂O₅Nanoparticles of V₂O₅Nanoparticles and doped in V₂O₅S element and Zn element in the lattice of the nanoparticles. At the moment, the hydrothermal reaction conditions are appropriate, which is favorable for preparing V₂O₅A nanoparticle; at the same time, S, Zn-codoped V was obtained₂O₅In the nanoparticles, V₂O₅The S, Zn doping amount in the crystal lattice is proper, lattice mutation and impurity phases are not introduced, and V can be effectively enhanced₂O₅The p-type performance of the nano particles improves the hole transmission capability.

The inventionA third aspect of embodiments provides a quantum dot light emitting diode including a cathode and an anode oppositely disposed, a quantum dot light emitting layer disposed between the cathode and the anode, and a hole transport layer disposed between the anode and the quantum dot light emitting layer, a material of the hole transport layer including V ₂O₅Nanoparticles and doped in V₂O₅S element and Zn element in the nanoparticle lattice.

In the quantum dot light-emitting diode provided by the embodiment of the invention, the hole transport layer contains V doped with S element and Zn element₂O₅And (3) nanoparticles. Due to the fact that at V₂O₅S element and Zn element are simultaneously doped in crystal lattices, so that V can be effectively improved₂O₅The hole transmission performance of the nano material can promote the effective recombination of electrons and holes in the quantum dot light-emitting layer when the nano material is used as a hole transmission layer of the quantum dot light-emitting diode, and the light-emitting performance of the quantum dot light-emitting diode is improved.

S, Zn co-doped V contained in the material of the hole transport layer in the embodiment of the present invention₂O₅The specific principle of using the material of the hole transport layer to improve the hole transport performance of the device is as described above, and for saving space, the description is omitted here.

In a preferred embodiment, the material of the hole transport layer is S, Zn co-doped V₂O₅Nanoparticles, i.e. V co-doped with S, Zn of the hole transport layer₂O₅And (4) preparing nanoparticles. In this case by Zn²⁺More obvious improvement of p-type V by doping₂O₅The hole carrier concentration of (2) is such that the acceptor level is more significantly increased by S, thereby imparting more excellent hole transport properties to the hole transport layer.

In some embodiments, the S, Zn co-doped V₂O₅In the nanoparticles, the ratio of the molar weight of the V element to the sum of the molar weights of the S element and the Zn element is 1: 0.05-0.1. V element and doping element (S)^2-、Zn²⁺) The molar ratio of (A) mainly affects V₂O₅The degree of S, Zn co-doping in the nanoparticles, in turn, affects S, Zn co-doped V₂O₅Hole transport properties of the nanoparticles. In particular, when the S, Zn codoped V₂O₅When the ratio of the molar amount of the V element to the sum of the molar amounts of the S element and the Zn element in the nanoparticles is 1:0.05 to 0.1, the doping amounts of the S element and the Zn element are appropriate, and V can be reduced₂O₅The valence band conduction band of the nano-particles improves the acceptor level to achieve enhanced V₂O₅Purpose of nanoparticle p-type properties. If the S, Zn codoped V₂O₅In the nanoparticles, the doping amounts of the S element and the Zn element are too high, so that S, Zn co-doped V₂O₅The ratio of the sum of the molar amounts of the S element and the Zn element to the molar amount of the V element in the nanoparticles is more than 0.1:1, which causes V₂O₅Mutation of the lattice, formation of new lattices and formation of impurities, affecting V₂O₅The property of the body reduces the hole transmission capability of the body. In particular, the S, Zn codoped V ₂O₅When the ratio of the sum of the molar amounts of the S element and the Zn element to the molar amount of the V element in the nanoparticles is greater than 0.1:1, the S element and the Zn element are present in the V₂O₅The solid solubility in the nanoparticles reaches saturation, and excessive S element and Zn element are gathered in S, Zn co-doped V₂O₅The surface of the crystal grain forms a new phase, and the nanometer V is reduced₂O₅Thereby changing the bulk material V₂O₅The properties of the nanoparticles; at the same time, an excess of S^2-And Zn²⁺Also enter V₂O₅Causes expansion of the crystal lattice, and generates large distortion and strain energy of the crystal lattice. The S, Zn codoped V₂O₅In the nano particles, the doping amount of the S element and the Zn element is too low, so that S, Zn codoped V₂O₅When the ratio of the sum of the molar amounts of the S element and the Zn element to the molar amount of the V element in the nanoparticles is less than 0.05:1, S, Zn is generated during the doping reactionLoss occurs and thus effective doping cannot be achieved.

Specifically, the quantum dot light emitting diode according to the embodiment of the present invention has a positive structure and an inversion structure.

In one embodiment, a positive structure quantum dot light emitting diode includes an anode and a cathode disposed opposite each other, a quantum dot light emitting layer disposed between the anode and the cathode, a hole transport layer disposed between the anode and the quantum dot light emitting layer, and the anode is disposed on a substrate. Further, a hole injection layer may be further disposed between the anode and the hole transport layer, and a hole functional layer such as an electron blocking layer may be further disposed between the anode and the quantum dot light emitting 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 positive type structure devices, the quantum dot light emitting diode includes a substrate, an anode disposed on the surface of the substrate, the hole injection layer disposed on the surface of the anode, a hole transport layer disposed on the surface of the hole injection layer, a quantum dot light emitting layer disposed on the surface of the hole transport layer, an electron transport layer disposed on the surface of the quantum dot light emitting layer, and a cathode disposed on the surface of the electron transport layer.

In one embodiment, an inversion-structured quantum dot light emitting diode includes a stacked structure including an anode and a cathode disposed opposite each other, a quantum dot light emitting layer disposed between the anode and the cathode, a hole transport layer disposed between the anode and the quantum dot light emitting layer, and the cathode disposed on a substrate. Further, a hole injection layer can be arranged between the anode and the hole transport layer, and a hole functional layer such as an electron blocking layer can be arranged between the anode and the quantum dot light emitting layer; and an electron functional layer such as an electron transport layer, an electron injection layer and a hole blocking layer can be arranged between the cathode and the quantum dot light-emitting layer. In some embodiments of the device with the 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, a hole injection layer disposed on a surface of the hole transport layer, and an anode disposed on a surface of the hole injection layer.

Specifically, the selection of the anode is not limited strictly, and ITO may be selected, but is not limited thereto. The thickness of the anode is 15-30 nm.

The material of the quantum dot light-emitting layer can be conventional quantum dot material according to conventional quantum dot type. For example, the quantum dot of the quantum dot light-emitting layer can be one of red quantum dot, green quantum dot, blue quantum dot and yellow quantum dot; the quantum dot material may or may not contain cadmium; the quantum dots can be oil-soluble quantum dots comprising binary phase, ternary phase and quaternary phase quantum dots. In some embodiments, the quantum dot material may be selected from semiconductor nanocrystals of CdS, CdSe, CdTe, ZnSe, ZnTe, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InSb, AlAs, AlP, CuInS, CuInSe, AgS, PbS, PbSe, and at least one of core-shell structured quantum dots or alloy structured quantum dots formed of the above materials; in some embodiments, the quantum dot material may be selected from Zn_XCd_1-XS、Cu_XIn_1-XS、Zn_XCd_1-XSe、Zn_XSe_1-XS、Zn_XCd_1-XTe、PbSe_XS_1-XAnd at least one of a core-shell structure quantum dot or an alloy structure quantum dot formed by the material. In some embodiments, the quantum dot material may be selected from Zn_XCd_1-XS/ZnSe、Cu_XIn_1-XS/ZnS、 Zn_XCd_1-XSe/ZnS、CuInSeS、Zn_XCd_1-XTe/ZnS、PbSe_XS_1-XThe nano-crystalline material comprises/ZnS semiconductor nano-crystalline and at least one of core-shell structure quantum dots or alloy structure quantum dots formed by the material. The quantum dot light-emitting layer formed by the quantum dot material has the characteristics of wide excitation spectrum, continuous distribution, high emission spectrum stability and the like. The thickness of the quantum dot light-emitting layer is 20-60 nm.

The cathode can be made of conventional cathode materials, such as metal silver or metal aluminum, or a nano Ag wire or a nano Cu wire, and the materials have low resistance so that carriers can be injected smoothly. The thickness of the cathode is 15-30 nm.

The electron transport layer can be made of electron transport materials conventional in the field, and can be ZnO or TiO₂、CsF、LiF、CsCO₃And Alq₃But is not limited thereto.

In some embodiments, the qd-led may further comprise an encapsulation layer. The packaging layer can be arranged on the surface of a top electrode (an electrode far away from the substrate) or on the surface of the whole quantum dot light-emitting diode.

The quantum dot light-emitting diode provided by the embodiment of the invention can be prepared by the following method.

A fourth aspect of the embodiments of the present invention provides a method for manufacturing a quantum dot light emitting diode, including the steps of:

E01. providing a substrate;

E02. depositing on the substrate surface a layer comprising V₂O₅Nanoparticles and doped in V₂O₅And preparing a hole transport layer by using an S element and a Zn element in the crystal lattices of the nano particles.

In the preparation method of the quantum dot light-emitting diode provided by the embodiment of the invention, S, Zn co-doped V ₂O₅The nanoparticles are used as a hole transport layer material, and the obtained hole transport layer material comprises V₂O₅Nanoparticles and doping at V₂O₅S element and Zn element in the nanoparticle lattice, thus, the amounts obtained by the embodiments of the present inventionThe quantum dot light-emitting diode can improve hole transmission capacity, promote electron-hole to be effectively compounded in the quantum dot light-emitting layer, further reduce the influence of exciton accumulation on the performance of the device, promote the injection balance of electrons and holes, improve the luminous efficiency of the quantum dot light-emitting diode, reduce the influence of exciton accumulation on the luminous efficiency of the quantum dot light-emitting diode device, and finally improve the performance of the quantum dot light-emitting diode device.

Specifically, in step E01, in the positive type structure quantum dot light emitting diode, the bottom electrode provided on the substrate is an anode, that is, the substrate at least includes an anode substrate. In some embodiments of the invention, the substrate is an anode substrate with an anode disposed on a substrate. In some embodiments of the present invention, the substrate may be a laminated substrate in which an anode is disposed on a substrate and a hole injection layer is disposed on a surface of the anode. It should be understood that the present invention is not limited to the structures of the above-described embodiments.

In step E01, in the case of the inverse quantum dot light emitting diode, the bottom electrode provided on the substrate is a cathode, that is, the substrate at least includes a cathode substrate. In some embodiments of the invention, the substrate is a laminated substrate with a quantum dot light emitting layer disposed on a substrate. In still other embodiments of the present invention, the substrate is a laminated substrate in which a cathode is provided on a substrate, an electron transport layer is provided on a surface of the cathode, and a quantum dot light emitting layer is provided on a surface of the electron transport layer. Of course, other electron functional layers, such as an electron injection layer, may also be provided between the cathode and the electron transport layer.

In the method for manufacturing a quantum dot light emitting diode according to the embodiment of the present invention, before a functional layer (e.g., a hole transport layer) is manufactured on a surface of the anode substrate or the cathode substrate, the anode substrate or the cathode substrate is preferably pretreated to obtain a high-quality functional layer (e.g., S-Zn co-doped V)₂O₅A nano-film). In a preferred embodiment, the step of pre-treating comprises: cleaning the anode substrate or the cathode substrate with a cleaning agent to primarily remove stains on the surface, and sequentially adding deionized water and acrylic acid Respectively ultrasonically cleaning ketone, absolute ethyl alcohol and deionized water for 10-30 min, preferably 20min to remove impurities existing on the surface; and finally, drying the anode substrate or the cathode substrate by using high-purity nitrogen to obtain the surface of the anode substrate or the cathode substrate.

The S-Zn codoped V in the embodiment of the invention₂O₅The nanomaterial is as described above and comprises V₂O₅Nanoparticles and doped in V₂O₅The nano material of the S element and the Zn element in the nano particle crystal lattice is not described herein for saving space. Depositing S-Zn co-doping V on the surface of the substrate₂O₅The nano-material can be formed by conventional solution processing methods, including but not limited to, dropping coating, spin coating, soaking, coating, printing, evaporation, and the like. The embodiment of the invention can control the film thickness by adjusting the concentration of the solution, the printing or spin coating speed and the deposition time. After the S-Zn co-doping of V is finished₂O₅And (3) after the nano material solution is subjected to thermal annealing treatment at 300-350 ℃, volatilizing the solvent in the nano material solution, promoting the nano materials to be uniformly and densely arranged, and preparing the compact film layer.

The functional layers (including but not limited to hole injection layer, electron transport layer, hole blocking layer, electron blocking layer) of the embodiments of the present application, except for the anode and cathode, can be prepared by conventional solution processing methods, including but not limited to ink-jet printing, spin coating, drop coating, dipping, coating, and evaporation. Similarly, the film thickness of each layer can be controlled by adjusting the concentration of the solution, the printing or spin coating speed and the deposition time; and carrying out thermal annealing treatment after the solution is deposited. In some embodiments, the electron transport layer can be prepared by placing the substrate in a vacuum evaporation chamber, and controlling the evaporation speed to be 0.01-0.5 nm/s, so as to prepare the electron transport layer with a proper thickness.

In some embodiments, the method further comprises performing packaging treatment on the obtained quantum dot light emitting diode. The packaging process can adopt a common machine for packaging and can also adopt manual packaging. 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 following description will be given with reference to specific examples and comparative examples.

Example 1

S, Zn codoped V₂O₅The preparation method of the nano material comprises the following steps:

1g of ammonium metavanadate, a proper amount of thiourea and zinc chloride are added into 30ml of water to prepare an aqueous solution, wherein the ratio of vanadium atoms: the molar ratio of sulfur atoms to zinc atoms is 1: 0.05; sulfur atom: the molar ratio of zinc atoms is 1: 3. To complete dissolution, 3ml of concentrated hydrochloric acid was added to the aqueous solution to adjust the pH of the aqueous solution<1, stirring for 30 min. Then the aqueous solution is transferred to a hydrothermal reaction kettle, reacted for 24 hours at the temperature of 200 ℃, and cooled and washed (water washing for 2 times, and absolute ethyl alcohol washing for 1 time). Drying at 50 deg.C to obtain S, Zn codoped V₂O₅And (3) nano materials.

Example 2

1g of sodium metavanadate, and appropriate amounts of sodium sulfide and sodium nitrate were added to 30ml of water to prepare an aqueous solution, wherein the molar ratio of vanadium atoms: the molar ratio of sulfur atoms to zinc atoms is 1: 0.08; sulfur atom: the molar ratio of zinc atoms is 1: 2.5. After complete dissolution, 3ml of concentrated nitric acid was added to the aqueous solution to adjust the pH of the aqueous solution<1, stirring for 30 min. Then the aqueous solution is transferred to a hydrothermal reaction kettle, reacted for 18h at the temperature of 250 ℃, and cooled and washed (water washing for 2 times, and absolute ethyl alcohol washing for 1 time). Drying at 50 deg.C to obtain S, Zn codoped V₂O₅And (3) nano materials.

Example 3

1g of potassium metavanadate, a proper amount of potassium sulfide and zinc sulfate are added into 30ml of water to prepare an aqueous solution, wherein the ratio of vanadium atoms: the molar ratio of sulfur atoms to zinc atoms is 1: 0.1; sulfur atom: the molar ratio of zinc atoms is1: 2. to complete dissolution, 3ml of concentrated sulfuric acid was added to the aqueous solution to adjust the pH of the aqueous solution<1, stirring for 30 min. Then the aqueous solution is transferred to a hydrothermal reaction kettle, reacted for 18 hours at the temperature of 180 ℃, and cooled and washed (water washing for 2 times, and absolute ethyl alcohol washing for 1 time). Drying at 50 deg.C to obtain S, Zn codoped V ₂O₅A nano-material.

Example 4

A 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, an electron transport layer arranged between the cathode and the quantum dot light-emitting layer, and a hole transport layer arranged between the anode and the quantum dot light-emitting layer, wherein the anode is arranged on a substrate. Wherein the substrate is made of glass sheet, the anode is made of ITO substrate, and the hole transport layer is made of S, Zn co-doped V₂O₅The nano material, the electron transport layer is made of ZnO, and the cathode is made of Al.

The preparation method of the quantum dot light-emitting diode comprises the following steps:

providing an ITO substrate, and preparing a hole transport layer on the ITO substrate, wherein the hole transport layer is made of S, Zn co-doped V prepared by the method in example 1₂O₅A nanomaterial;

depositing a quantum dot light emitting layer on the hole transport layer;

depositing an electron transport layer over the quantum dot light emitting layer;

preparing a cathode on the electron transport layer.

Example 5

A 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, an electron transport layer arranged between the cathode and the quantum dot light-emitting layer, and a hole transport layer arranged between the anode and the quantum dot light-emitting layer, wherein the anode is arranged on a substrate. Wherein the substrate is made of glass The anode is made of ITO substrate, and the hole transport layer is made of S, Zn co-doped V₂O₅The nano material, the electron transport layer is made of ZnO, and the cathode is made of Al.

providing an ITO substrate, and preparing a hole transport layer on the ITO substrate, wherein the hole transport layer is made of S, Zn co-doped V prepared by the method in example 2₂O₅A nanomaterial;

depositing a quantum dot light emitting layer on the hole transport layer;

preparing a cathode on the electron transport layer.

Example 6

providing an ITO substrate, and preparing a hole transport layer on the ITO substrate, wherein the hole transport layer is made of S, Zn co-doped V prepared by the method in example 3₂O₅A nanomaterial;

depositing a quantum dot light emitting layer on the hole transport layer;

preparing a cathode on the electron transport layer.

Example 7

A 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, an electron transport layer arranged between the cathode and the quantum dot light-emitting layer, and a hole transport layer arranged between the anode and the quantum dot light-emitting layer, wherein the cathode is arranged on a substrate. Wherein the substrate is made of glass sheet, the cathode is made of ITO substrate, and the hole transport layer is made of S, Zn co-doped V₂O₅The nano material, the electron transmission layer is made of ZnO, and the anode is made of Al.

providing a cathode substrate, and depositing and preparing an electron transport layer on the cathode substrate;

Preparing a quantum dot light-emitting layer on the electron transport layer;

preparing a hole transport layer on the quantum dot light emitting layer, wherein the material of the hole transport layer is S, Zn co-doped V prepared by the method in example 1₂O₅A nanomaterial;

and preparing an anode on the hole transport layer.

Example 8

preparing a quantum dot light-emitting layer on the electron transport layer;

preparing a hole transport layer on the quantum dot light emitting layer, wherein the material of the hole transport layer is S, Zn co-doped V prepared by the method in example 2 ₂O₅A nanomaterial;

and preparing an anode on the hole transport layer.

Example 9

preparing a quantum dot light-emitting layer on the electron transport layer;

preparing a hole transport layer on the quantum dot light emitting layer, wherein the material of the hole transport layer is S, Zn co-doped V prepared by the method in example 3₂O₅A nanomaterial;

an anode is prepared on the hole transport layer.

Comparative example 1

A 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, an electron transport layer arranged between the cathode and the quantum dot light-emitting layer, and a hole transport layer arranged between the anode and the quantum dot light-emitting layer, wherein the cathode is arranged on a substrate. Wherein the substrate is made of glass sheet, the anode is made of ITO substrate, The material of the hole transport layer was commercial V₂O₅The material (purchased from sigma company), the material of the electron transport layer is ZnO, and the material of the cathode is Al.

The performance tests of the hole transport layers prepared in the examples 4 to 9 and the comparative example 1, the hole transport layer prepared in the comparative example 1, the quantum dot light-emitting diodes prepared in the examples 4 to 9 and the comparative example 1 are carried out, and the test indexes and the test methods are as follows:

(1) hole mobility: testing the current density (J) -voltage (V) of the hole transport layer, drawing a curve relation graph, fitting a Space Charge Limited Current (SCLC) region in the relation graph, and then calculating the hole mobility according to a well-known Child's law formula:

J＝(9/8)ε_rε₀μ_eV²/d³

wherein J represents current density in mAcm^-2；ε_rDenotes the relative dielectric constant,. epsilon₀Represents a vacuum dielectric constant; mu.s_eDenotes hole mobility in cm²V^-1s^-1(ii) a V represents the drive voltage, in units of V; d represents the film thickness in m.

(2) Resistivity: the resistivity of the electron transport film is measured by the same resistivity measuring instrument.

(3) External Quantum Efficiency (EQE): measured using an EQE optical test instrument.

Note: the hole mobility and resistivity were tested as single layer thin film structure devices, i.e.: cathode/hole transport layer/anode. The external quantum efficiency test is the QLED device, namely: anode/hole transport layer/quantum dot/electron transport film/cathode, or cathode/electron transport film/quantum dot/hole transport layer/anode.

The test results are shown in table 1 below:

TABLE 1

As can be seen from Table 1 above, examples 1-3 of the present invention provide S, Zn as the materialCodoped V₂O₅The hole transport layer made of nano material has the resistivity which is obviously lower than that of V in comparative example 1₂O₅The resistivity and hole mobility of the hole transport layer made of the material are significantly higher than those of the hole transport layer made of the metal compound nanomaterial in comparative example 1.

The quantum dot light-emitting diodes provided in embodiments 4 to 9 of the present invention (the hole transport layer material is S, Zn co-doped with V)₂O₅Nanomaterial) external quantum efficiency significantly higher than V in comparative example 1₂O₅The external quantum efficiency of the quantum dot light-emitting diode made of the material shows that the quantum dot light-emitting diode obtained by the embodiment has better luminous efficiency.

It is noted that the embodiments provided by the present invention all use blue light quantum dots Cd_XZn_1-XS/ZnS is used as a material of a luminescent layer, is based on that a blue light luminescent system is a system which is used more (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

1. The preparation method of the nano material is characterized by comprising the following steps of:

preparing an aqueous solution of a vanadium source, a sulfur source and a zinc source according to the proportion that the molar weight of the V element and the sum of the molar weights of the S element and the Zn element are 1: 0.05-0.1, adding protonic acid into the aqueous solution, and adjusting the pH value of the aqueous solution to be less than or equal to 2; carrying out hydrothermal reaction at the temperature of not lower than 150 ℃ to prepare a nano material; the nano material comprises V₂O₅Nanoparticles and doped in V₂O₅S element and Zn element in the nanoparticle lattice;

the time of the hydrothermal reaction is 8-30 hours.

2. The method for preparing a nanomaterial according to claim 1, wherein in the step of preparing the aqueous solution of a vanadium source, a sulfur source, and a zinc source, the aqueous solution of a vanadium source, a sulfur source, and a zinc source is prepared in such a manner that the molar ratio of the S element to the Zn element is 1:2 to 3.

3. The method for preparing nanomaterial according to claim 1, wherein in the step of adjusting the pH of the aqueous solution, a protonic acid is added to the aqueous solution to adjust the pH of the aqueous solution to 1 or less.

4. The method according to claim 3, wherein the protonic acid is at least one selected from the group consisting of concentrated sulfuric acid, concentrated nitric acid, and concentrated hydrochloric acid.

5. The method for preparing nanomaterials of any one of claims 1 to 4, wherein the vanadium source is selected from at least one of ammonium metavanadate, potassium metavanadate, and sodium metavanadate; and/or

The sulfur source is at least one selected from sodium sulfide, potassium sulfide, thiourea and ammonium sulfide; and/or

The zinc source is at least one selected from zinc acetate, zinc nitrate, zinc chloride and zinc sulfate.

6. The method for preparing nanomaterials of any one of claims 1 to 4, comprising the steps of:

preparing an aqueous solution of a vanadium source, a sulfur source and a zinc source according to the ratio of the molar weight of a V element to the sum of the molar weights of an S element and a Zn element of 1: 0.05-0.1 and the molar ratio of the S element to the Zn element of 1: 2-3, adding a protonic acid into the aqueous solution, and adjusting the pH value of the aqueous solution to be less than or equal to 1; carrying out hydrothermal reaction at the temperature of 150-220 ℃, reacting for 18-30 hours, and preparing a nano material; the nano material is S, Zn co-doped V₂O₅Nanoparticles of V₂O₅Nanoparticles and doped in V₂O₅S element and Zn element in the nanoparticle lattice.

7. The method for preparing nanomaterials according to any one of claims 1 to 4, comprising the steps of: the hydrothermal reaction is carried out for 8 to 30 hours at a temperature of 150 to 220 ℃.

8. A nanomaterial as claimed in any of claims 1 to 7 wherein the nanomaterial comprises V₂O₅Nanoparticles and doped in V₂O₅S element and Zn element in the nanoparticle lattice.

9. The nanomaterial according to claim 8, wherein a ratio of a molar amount of the V element to a sum of molar amounts of the S element and the Zn element in the nanomaterial is 1:0.05 to 0.1.

10. The nanomaterial of claim 9, wherein a molar ratio of the S element to the Zn element in the nanomaterial is 1:2 to 3.

11. A quantum dot light emitting diode comprising a cathode and an anode disposed opposite to each other, a quantum dot light emitting layer disposed between the cathode and the anode, and a hole transport layer disposed between the anode and the quantum dot light emitting layer, wherein a material of the hole transport layer comprises a nanomaterial prepared by the method according to any one of claims 1 to 7, and the nanomaterial comprises V₂O₅Nanoparticles and doped in V₂O₅S element and Zn element in the nanoparticle lattice.

12. The qd-led of claim 11, wherein the ratio of the molar amount of the V element to the sum of the molar amounts of the S element and the Zn element in the material of the hole transporting layer is 1: 0.05-0.1.

13. The qd-led of claim 12, wherein the molar ratio of S element to Zn element in the material of the hole transport layer is 1:2 to 3.