Quantum dot electroluminescent device, preparation method thereof and display device
By using GaN or GaAlN or AlGaInN as quantum dot electroluminescent devices as electron transport materials, the device instability problem caused by zinc oxide nanocrystals is solved, and the technical effect of long life and high brightness is achieved.
Patent Information
- Application Number
- CN202410067165.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-17
- Publication Date
- 2025-07-18
AI Technical Summary
Among existing quantum dot light-emitting diodes, zinc oxide nanocrystals as electron transport materials lead to unstable device performance and cannot reflect the longer life advantage of quantum dot materials.
GaN, GaAlN or AlGaInN are used as the N-type semiconductor layer as the electron transport material, and a quantum dot luminescence layer is prepared in combination with solution method or photolithography to form a stable quantum dot electroluminescence device.
The lifetime and brightness of quantum dot electroluminescent devices are improved, and higher electron injection efficiency and device stability are achieved.
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Figure CN120344086A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the technical field of quantum dot electroluminescence, and in particular to a quantum dot electroluminescence device and a preparation method thereof and a display device. Background Art
[0002] A light-emitting device is a device that converts electrical energy into light energy, such as an organic light-emitting element whose light-emitting material is an organic material and a quantum dot light-emitting element whose light-emitting material is a quantum dot.
[0003] In the past decade, a new generation of quantum dot light-emitting diodes (QD-LEDs) has emerged. Thanks to the progress of quantum dot synthesis technology in the past two or three decades, the luminescence efficiency of core-shell structure quantum dots can be as high as 100%; and the luminescence spectrum of quantum dots is easy to adjust. As long as the size of the quantum dots is changed or other elements are added, the luminescence wavelength can be adjusted in all visible bands and can be extended to the near-infrared band and the near-ultraviolet band, which greatly increases its development and utilization prospects. In addition, the half-peak width of the quantum dot luminescence spectrum is narrow, generally less than 30nm, which meets an important condition for LED to be a high-performance display device. Another important factor is that the photochemical stability of quantum dots is greatly improved compared to organic materials, which can effectively extend the life of LED devices and meet commercial requirements. At the same time, quantum dot light-emitting diodes can be processed and produced on a large scale through the full solution process, which greatly reduces the production cost of LEDs.
[0004] However, the current quantum dot light-emitting diode technology generally uses zinc oxide nanocrystals as electron transport materials, which still limits the lifespan of QD-LEDs and cannot reflect the theoretically achievable advantage of quantum dot light-emitting materials with longer lifespans. Summary of the invention
[0005] The purpose of the present disclosure is to provide a quantum dot electroluminescent device to solve the problem of unstable device performance caused by the instability of nanocrystalline electron transport materials used in the prior art.
[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present disclosure, a quantum dot electroluminescent device is provided, comprising a substrate; a first electrode, arranged on a surface on one side of the substrate; an electron transport layer, arranged on a surface of the first electrode away from the substrate or on a surface of the substrate, the electron transport layer is an N-type semiconductor layer, and the semiconductor layer material is selected from GaN or GaAlN or AlGaInN; a quantum dot light-emitting layer, arranged on a surface of the electron transport layer away from the substrate; and a second electrode, arranged on a surface of the quantum dot light-emitting layer away from the substrate.
[0007] Optionally, the thickness of the electron transport layer is 10 to 5000 nm.
[0008] Optionally, the N-type semiconductor layer has a doping element, which is Si or Ge, and the doping concentration is 1×10 15 ~1×10 21 cm -3 。
[0009] Optionally, the quantum dot electroluminescent device further includes a hole transport layer, which is located between the second electrode and the quantum dot light-emitting layer.
[0010] Optionally, the quantum dot electroluminescent device further includes a hole injection layer, which is located between the second electrode and the quantum dot light-emitting layer.
[0011] Optionally, the quantum dot electroluminescent device further includes an electron blocking layer, which is located between the electron transport layer and the quantum dot light-emitting layer.
[0012] Optionally, the electron blocking layer is a GaN layer or an Al2O3 layer or a SiO2 layer.
[0013] According to another aspect of the present disclosure, there is provided a method for manufacturing the quantum dot electroluminescent device of any one of the above, including: preparing a substrate and a first electrode; disposing an N-type semiconductor layer on the first electrode, the semiconductor layer material being selected from GaN or GaAlN or AlGaInN, to obtain an electron transport layer; preparing a quantum dot light-emitting layer on the electron transport layer by a solution method or a photolithography method; and disposing a second electrode on the quantum dot light-emitting layer.
[0014] Optionally, prepare an N-type semiconductor layer, and bond the N-type semiconductor layer and the first electrode to obtain an electron transport layer.
[0015] Optionally, the solution method is one of inkjet printing, spin coating or spraying.
[0016] Optionally, preparing the N-type semiconductor layer includes epitaxially growing the N-type semiconductor layer on another substrate, and then peeling to obtain the N-type semiconductor layer.
[0017] According to another aspect of the present disclosure, there is provided a method for manufacturing the quantum dot electroluminescent device of any one of the above, including: preparing a substrate; disposing an N-type semiconductor layer on the substrate; disposing a first electrode on a first region of the N-type semiconductor layer; preparing a quantum dot light-emitting layer on a second region of the N-type semiconductor layer by a solution method or a photolithography method; and disposing a second electrode on the quantum dot light-emitting layer.
[0018] According to still another aspect of the present disclosure, there is provided a display device, which includes the quantum dot electroluminescent device of any one of the above.
[0019] Applying the above technical solution, the above N-type semiconductor material can well meet the requirements of the electron injection material as the electron transport material, so that the quantum dot electroluminescent device has the technical advantages of long life and high brightness. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The accompanying drawings forming a part of this application are used to provide a further understanding of the present disclosure. The illustrative embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation of the present disclosure. In the drawings:
[0021] Figure 1 It is a schematic structural diagram of a quantum dot electroluminescent device of the present disclosure.
[0022] Figure 2 It is a schematic structural diagram of a quantum dot electroluminescent device of the present disclosure.
[0023] Figure 3 It is a schematic structural diagram of a quantum dot electroluminescent device of the present disclosure.
[0024] Figure 4 It is a schematic structural diagram of a quantum dot electroluminescent device of the present disclosure.
[0025] Figure 5 It is a schematic structural diagram of a quantum dot electroluminescent device of the present disclosure.
[0026] Figure 6 It is a schematic structural diagram of a quantum dot electroluminescent device of the present disclosure.
[0027] Note that in the embodiments described below, sometimes the same reference numerals are used between different drawings to denote the same parts or parts having the same functions, and the repeated description thereof is omitted. In some cases, similar reference numerals and letters are used to denote similar items. Therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.
[0028] For the sake of easy understanding, the positions, sizes, ranges, etc. of the various structures shown in the drawings and the like sometimes do not represent the actual positions, sizes, ranges, etc. Therefore, the present disclosure is not limited to the positions, sizes, ranges, etc. disclosed in the drawings and the like. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0029] The various exemplary embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that: Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present disclosure.
[0030] The following description of at least one exemplary embodiment is merely illustrative and is in no way a limitation of the present disclosure or its application or use. That is, the structures and methods herein are shown in an exemplary manner to illustrate different embodiments of the structures and methods of the present disclosure. However, those skilled in the art will understand that they merely illustrate exemplary ways in which the present disclosure can be implemented, rather than exhaustive ways. In addition, the drawings are not necessarily drawn to scale, and some features may be enlarged to show details of specific components.
[0031] In addition, technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be considered as part of the authorization specification.
[0032] In all examples shown and discussed herein, any specific values should be construed as merely exemplary, rather than as limitations. Thus, other examples of exemplary embodiments may have different values.
[0033] In the specification and claims, words such as "left", "right", "front", "rear", "top", "bottom", "upper", "lower", "high", "low", etc., if any, are used for descriptive purposes and not necessarily for describing invariant relative positions. It should be understood that such words are interchangeable under appropriate circumstances, such that the embodiments of the present disclosure described herein, for example, can operate in other orientations different from those shown or otherwise described herein. For example, when the device in the drawings is inverted, a feature originally described as "above" other features can then be described as "below" other features. The device can also be oriented in other ways (rotated 90 degrees or in other orientations), and the relative spatial relationships will be correspondingly interpreted.
[0034] In the specification and claims, when an element is said to be "on", "attached" to, "connected" to, "coupled" to, or "operatively coupled" to another element, etc., the element can be directly on, directly attached to, directly connected to, directly coupled to, or directly operatively coupled to the other element, or there can be one or more intermediate elements. In contrast, when an element is said to be "directly" on, "directly attached" to, "directly connected" to, "directly coupled" to, or "directly operatively coupled" to another element, there will be no intermediate element. In the specification and claims, a feature being arranged "adjacent" to another feature can mean that the feature has a portion overlapping with the adjacent feature or a portion above or below the adjacent feature.
[0035] As used herein, the term "exemplary" means "serving as an example, instance, or illustration" and not as a "model" to be precisely copied. Any implementation described herein as exemplary is not necessarily to be construed as preferred or advantageous over other implementations. Moreover, the present disclosure is not limited by any theory expressed or implied in the technical field, background art, summary of the invention, or detailed description.
[0036] As used herein, the term "about" means to include any minute variations due to manufacturing tolerances, imperfections in the device or element, environmental effects, and / or other factors.
[0037] In addition, for reference purposes only, the terms "first", "second", and the like may also be used herein and are not intended to be limiting. For example, unless the context clearly indicates otherwise, the terms "first", "second", and other such numerical terms referring to a structure or element do not imply an order or sequence.
[0038] It should also be understood that the term "comprising" as used herein specifies the presence of the stated features, integers, steps, operations, units, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, units, and / or components and / or combinations thereof.
[0039] In the present disclosure, the term "provide" is used broadly to encompass all manners of obtaining an object, and thus "providing an object" includes, but is not limited to, "purchasing", "preparing / manufacturing", "arranging / setting", "installing / assembling", and / or "ordering" the object, etc. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the present disclosure. As used herein, the singular forms "a", "an", and "the" are also intended to include the plural forms unless the context clearly indicates otherwise.
[0040] According to a first aspect of the present disclosure, there is provided a quantum dot electroluminescent device, comprising a substrate; a first electrode disposed on a surface of one side of the substrate; an electron transport layer disposed on a surface of the first electrode away from the substrate or disposed on the surface of the substrate, the electron transport layer being an N-type semiconductor layer, and the semiconductor layer material being selected from GaN or GaAlN or AlGaInN; a quantum dot light-emitting layer disposed on a surface of the electron transport layer away from the substrate; and a second electrode disposed on a surface of the quantum dot light-emitting layer away from the substrate. Taking GaN crystal as an example, compared with traditional zinc oxide nanocrystal electron transport materials, its physical and chemical properties are more stable. The bandgap width of GaN is 3.4 eV, which is greater than that of common blue light quantum dot materials and much greater than that of red and green quantum dot materials. Its LUMO energy level position is about 4.0 eV, which is close to that of zinc oxide, facilitating electron injection. Its HOMO energy level position is about 7.4 eV, which can effectively block holes. Therefore, the N-type semiconductor material as an electron transport material can well meet the requirements of an electron injection material, and the quantum dot electroluminescent device has the technical advantages of long lifespan and high brightness. By adding different proportions of Al and In elements to GaN, its bandgap width and conduction band energy level position can be effectively adjusted to better match the quantum dot material and further improve the performance of the quantum dot electroluminescent device.
[0041] In some embodiments, when the electron transport layer is disposed on the substrate, the quantum dot light-emitting layer is disposed on a surface of the electron transport layer away from the substrate, and the first electrode is also disposed on a surface of the electron transport layer away from the substrate. In some embodiments, the orthographic projection area of the quantum dot light-emitting layer on the substrate is greater than the orthographic projection area of the first electrode on the substrate. As Figure 5 shown.
[0042] In some embodiments, the thickness of the electron transport layer is 10 - 5000 nm. In some embodiments, the thickness of the electron transport layer is 20 - 3000 nm, or 20 - 4000 nm, or 20 - 3000 nm, or 20 - 2000 nm, or 20 - 1000 nm, or 500 - 1000 nm, or 500 - 2000 nm, or 500 - 3000 nm, or 500 - 4000 nm, or 500 - 5000 nm.
[0043] In some embodiments, the N-type semiconductor layer has a doping element, the doping element being Si or Ge, and the doping concentration being 1×10 15 ~1×10 21 cm -3 . By adjusting the doping concentration, the electron mobility can be adjusted, which is beneficial to selecting other matching device materials accordingly. The doping concentration can be 1×10 15 ~1×10 20 cm -3 , and the doping concentration is 1×1015 ~1×10 19 cm -3 ,with a doping concentration of 1×10 15 ~1×10 18 cm -3 ,with a doping concentration of 1×10 15 ~1×10 17 cm -3 ,with a doping concentration of 1×10 15 ~1×10 16 cm -3 ,
[0044] In some embodiments, the quantum dot electroluminescent device further includes a hole transport layer, which is located between the second electrode and the quantum dot light-emitting layer. In some embodiments, the hole transport material is selected from (N-carbazolyl)-1,1'-biphenyl (CBP), 1,3-bis(N-carbazolyl)benzene (MCP), N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPB), N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-2,7-diamino-9,9-spirobifluorene (Spiro-NPB), 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline] (TAPC), 4,4',4''-tris-9-carbazolyltriphenylamine (TCTA), poly(9,9-dioctylfluorene-alt-N-(4-butylphenyl)diphenylamine) (TFB), poly((9,9-dioctylfluorenyl-2,7-diyl)-alt-(9-(2-ethylhexyl)-carbazol-3,6-diyl)) (PF8CZ) or poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (POLY-TPD). The thickness range of the hole transport layer can be 10~500nm.
[0045] In some embodiments, the quantum dot electroluminescent device further includes a hole injection layer, which is located between the second electrode and the quantum dot light-emitting layer. In some embodiments, the hole injection material is selected from dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN) or MoO3. The thickness range of the hole injection layer can be 5~50nm.
[0046] In some embodiments, there may be a multi-layer structure between the quantum dot light-emitting layer and the second electrode, including a hole injection layer / hole transport layer structure, a hole injection layer / hole transport layer / luminescence assisting layer structure, a hole injection layer / luminescence assisting layer structure, a hole transport layer / luminescence assisting layer structure, or a hole injection layer / hole transport layer / hole blocking layer structure. In each structure, the layers are stacked on the second electrode in the above order successively. In some embodiments, the device structure of the quantum dot electroluminescent device refers to Figure 3 .
[0047] In some embodiments, the quantum dot electroluminescent device further includes an electron blocking layer, which is located between the electron transport layer and the quantum dot light-emitting layer. In some embodiments, the thickness of the electron blocking layer is 1 to 100 nm.
[0048] In some embodiments, the electron blocking layer is a GaN layer, an Al2O3 layer, or a SiO2 layer. When there is an excess of electrons injected by the electron transport layer, an intrinsic crystalline GaN (undoped), Al2O3, or SiO2 with a certain thickness can be grown continuously on the N-type semiconductor layer to play a role in blocking electrons.
[0049] In some embodiments, the quantum dot light-emitting layer includes at least one kind of quantum dot. The core of the quantum dot can be selected from II-VI group compounds, III-VI group compounds, I-III-VI group compounds, III-V group compounds, III-II-V group compounds, IV-VI group compounds, group IV elements, group IV compounds, and their combinations. The full width at half maximum (FWHM) of the emission peak of the fluorescence emission spectrum of the quantum dot can be less than or equal to about 45 nm, or less than or equal to about 40 nm, or less than or equal to about 30 nm. In some embodiments, the quantum dot light-emitting layer includes one or more layers.
[0050] In some embodiments, the quantum dot electroluminescent device may further include other functional layers, which are located between the above-mentioned layers.
[0051] In some embodiments, the quantum dot electroluminescent device includes one or more light-emitting units. The multiple light-emitting units are, for example, red, green, and blue light-emitting units.
[0052] In some embodiments, the first electrode material is selected from one or more of Au, Ag, Al, Cu, and Si. In some embodiments, the thickness of the first electrode is 20 to 1000 nm, preferably 50 to 200 nm. The first electrode is one or more layers.
[0053] In some embodiments, the second electrode material is selected from lithium (Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), ytterbium (Yb), silver-ytterbium (Ag-Yb), ITO, IZO, or a combination thereof. The second electrode can be one or more layers. In some embodiments, the thickness of the second electrode is 10 - 1000 nm, preferably 20 - 150 nm. When the second electrode is a light-emitting electrode, the thickness of the second electrode needs to be controlled within a range with a relatively high transmittance.
[0054] In some embodiments, the quantum dot electroluminescent device includes a pixel array, such as including a plurality of red, green, and blue sub-pixels.
[0055] According to the second aspect of the present disclosure, there is provided a method for manufacturing the quantum dot electroluminescent device of any one of the above, including preparing a substrate and a first electrode; disposing the N-type semiconductor layer on the first electrode, the semiconductor layer material being selected from GaN, GaAlN, or AlGaInN, to obtain the electron transport layer; preparing the quantum dot light-emitting layer on the electron transport layer by a solution method or a photolithography method; and disposing a second electrode on the quantum dot light-emitting layer. In the above manufacturing method, since the material of the electron transport layer is a stable material, the formula of the raw materials of the quantum dot light-emitting layer, such as quantum dot ink or quantum dot glue, has a wider selection range, and the process is easier to implement.
[0056] The solution method means that the quantum dots are in a solution state for device manufacturing. The photolithography method means that the quantum dot light-emitting layer can be patterned by using a mask and light conditions. The photolithography method can achieve a relatively high resolution of the quantum dot electroluminescent device.
[0057] In some embodiments, the N-type semiconductor layer is prepared in-situ. The preparation method of the N-type semiconductor layer can be MOCVD.
[0058] In some embodiments, the N-type semiconductor layer is prepared ex-situ. The specific method includes: preparing the N-type semiconductor layer, bonding the N-type semiconductor layer and the first electrode to obtain the electron transport layer; in some embodiments, the bonding method is thermal bonding. In some embodiments, preparing the N-type semiconductor layer includes epitaxially growing the N-type semiconductor layer on a substrate, and then peeling to obtain the N-type semiconductor layer. The substrate can be sapphire, silicon carbide, or silicon nitride, etc. The peeling method can be laser.
[0059] In some embodiments, the substrate is a substrate including thin film transistors or driving circuits. In some embodiments, the substrate includes sapphire, silicon carbide or silicon nitride layers. In some embodiments, the substrate is a substrate with a pixel isolation structure. In some embodiments, for preparing the substrate and the first electrode, one can directly purchase the component where the first electrode and the substrate are already combined, or it can include purchasing the substrate and then setting the first electrode on the substrate and then forming the combined component.
[0060] In some embodiments, the quantum dot electroluminescent device includes one or more light-emitting units. At least one light-emitting unit is prepared according to the above method.
[0061] In some embodiments, the preparation methods of the first electrode and the second electrode can independently be evaporation or sputtering.
[0062] In some embodiments, the solution method is one of inkjet printing, spin coating or spraying.
[0063] In some embodiments, the preparation method further includes setting a hole transport layer, and the hole transport layer is located between the second electrode and the quantum dot light-emitting layer.
[0064] In some embodiments, the preparation method further includes setting a hole injection layer, and the hole injection layer is located between the second electrode and the quantum dot light-emitting layer.
[0065] In some embodiments, the hole transport layer or the hole injection layer can be prepared by methods such as inkjet printing, deposition, sputtering or coating.
[0066] In some embodiments, the preparation method further includes setting an electron blocking layer, and the electron blocking layer is located between the electron transport layer and the quantum dot light-emitting layer.
[0067] In some embodiments, the electron blocking layer is a GaN layer, an Al2O3 layer or an SiO2 layer. When there is an excess of electrons injected by the electron transport layer, an intrinsic crystalline GaN (undoped) or Al2O3 or SiO2 with a certain thickness can be continuously grown on the N-type semiconductor layer to play a role in blocking electrons.
[0068] In some embodiments, the preparation method can further include setting other functional layers, which are located between the above-mentioned layers. In some embodiments, the other functional layers can be prepared by methods such as inkjet printing, deposition, sputtering or coating.
[0069] According to the third aspect of the present disclosure, there is provided a method for preparing the above-mentioned quantum dot electroluminescent device, including: preparing a substrate; setting the N-type semiconductor layer on the substrate; setting a first electrode on a first region of the N-type semiconductor layer; preparing a quantum dot light-emitting layer on a second region of the N-type semiconductor layer by a solution method or a photolithography method; and setting a second electrode on the quantum dot light-emitting layer.
[0070] In some embodiments, the first region and the second region do not overlap.
[0071] In some embodiments, the solution method is one of inkjet printing, spin coating, or spraying.
[0072] In some embodiments, the preparation method further includes providing a hole transport layer, which is located between the second electrode and the quantum dot light-emitting layer.
[0073] In some embodiments, the preparation method further includes providing a hole injection layer, which is located between the second electrode and the quantum dot light-emitting layer.
[0074] In some embodiments, the hole transport layer or the hole injection layer can be prepared by methods such as inkjet printing, deposition, sputtering, or coating.
[0075] In some embodiments, the preparation method further includes providing an electron blocking layer, which is located between the electron transport layer and the quantum dot light-emitting layer.
[0076] In some embodiments, the electron blocking layer is a GaN layer, an Al2O3 layer, or an SiO2 layer. When there is an excess of electrons injected by the electron transport layer, an intrinsic crystalline GaN (undoped), Al2O3, or SiO2 with a certain thickness can be grown continuously on the N-type semiconductor layer to play a role in blocking electrons.
[0077] In some embodiments, the preparation method may further include providing other functional layers, which are located between the above-mentioned layers. In some embodiments, the other functional layers can be prepared by methods such as inkjet printing, deposition, sputtering, or coating.
[0078] In some embodiments, the preparation method of the N-type semiconductor layer can be MOCVD. In some embodiments, the preparation methods of the first electrode and the second electrode can be independently evaporation or sputtering.
[0079] According to the fourth aspect of the present disclosure, a display device is provided, and the display device includes any one of the above-mentioned quantum dot electroluminescent devices. The display device having the above device structure has the technical advantages of long lifespan and high brightness.
[0080] Although some specific embodiments of the present disclosure have been described in detail by way of examples, those skilled in the art should understand that the above examples are only for illustration purposes and not for limiting the scope of the present disclosure. The various embodiments disclosed herein can be combined arbitrarily without departing from the spirit and scope of the present disclosure. Those skilled in the art should also understand that various modifications can be made to the embodiments without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.
Claims
1. A quantum dot electroluminescent device, characterized in that, Comprising a substrate; A first electrode disposed on a surface of one side of the substrate; An electron transport layer disposed on a surface of the first electrode away from the substrate or on a surface of the substrate, the electron transport layer being an N-type semiconductor layer, and the semiconductor layer material being selected from GaN or GaAlN or AlGaInN; A quantum dot light-emitting layer disposed on a surface of the electron transport layer away from the substrate; A second electrode disposed on a surface of the quantum dot light-emitting layer away from the substrate.
2. The quantum dot electroluminescent device according to claim 1, wherein The thickness of the electron transport layer is 10 to 5000 nm.
3. The quantum dot electroluminescent device according to claim 1, wherein The N-type semiconductor layer has a doping element, and the doping element is Si or Ge, with a doping concentration of 1×10 15 ~1×10 21 cm -3 .
4. The quantum dot electroluminescent device according to claim 1, wherein The quantum dot electroluminescent device further comprises a hole transport layer, and the hole transport layer is located between the second electrode and the quantum dot light-emitting layer.
5. The quantum dot electroluminescent device according to claim 1, wherein The quantum dot electroluminescent device further comprises a hole injection layer, and the hole injection layer is located between the second electrode and the quantum dot light-emitting layer.
6. The quantum dot light-emitting device according to claim 1, wherein The quantum dot electroluminescent device further comprises an electron blocking layer, and the electron blocking layer is located between the electron transport layer and the quantum dot light-emitting layer.
7. The quantum dot electroluminescent device according to claim 6, wherein The electron blocking layer is a GaN layer or an Al2O3 layer or a SiO2 layer.
8. A method for preparing a quantum dot electroluminescent device according to any one of claims 1 to 7, characterized in that, Comprising: Preparing the substrate and the first electrode; Disposing the N-type semiconductor layer on the first electrode, the semiconductor layer material being selected from GaN or GaAlN or AlGaInN, to obtain the electron transport layer; Preparing a quantum dot light-emitting layer on the electron transport layer by a solution method or a photolithography method; Disposing the second electrode on the quantum dot light-emitting layer.
9. The preparation method of the quantum dot electroluminescent device according to claim 8, wherein Preparing an N-type semiconductor layer, and bonding the N-type semiconductor layer and the first electrode to obtain the electron transport layer.
10. The preparation method of the quantum dot electroluminescent device according to claim 8, wherein The solution method is one of inkjet printing, spin coating or spraying.
11. The method for preparing a quantum dot electroluminescent device according to claim 9, wherein The preparing of the N-type semiconductor layer includes epitaxially growing an N-type semiconductor layer on another substrate, and then peeling to obtain the N-type semiconductor layer.
12. A method for preparing a quantum dot electroluminescent device according to any one of claims 1 to 7, characterized in that, Comprising: Preparing a substrate; Disposing the N-type semiconductor layer on the substrate; Disposing a first electrode on a first region of the N-type semiconductor layer; Preparing a quantum dot light-emitting layer on a second region of the N-type semiconductor layer by a solution method or a photolithography method; Disposing the second electrode on the quantum dot light-emitting layer.
13. A display device, characterized in that, The display device comprises the quantum dot electroluminescent device according to any one of claims 1 to 7.