Patterning preparation method of all-inorganic metal halide perovskite double-layer film

Abstract

The invention belongs to the technical field of semiconductor materials and photoelectricity, and particularly relates to a patterning preparation method of an all-inorganic metal halide perovskite double-layer thin film. Comprising the following steps: dissolving a first halide, tetraphenyl phosphorus halide, polyoxyethylene sorbitan monolaurate and alkaline earth metal halide salt in DMSO (Dimethylsulfoxide), heating and stirring until all the materials are dissolved to obtain a solution A; spin-coating and distributing the solution A on the surface of the substrate A to obtain a substrate B; depositing a second halide on the surface of the substrate B through the patterned metal mask plate to obtain a perovskite double-layer film; wherein the first halide is cesium halide or lead halide; the second halide is cesium halide or lead halide; the first halide is different from the second halide; according to the invention, the technical problems of insufficient ion diffusion length and limited additive introduction in the sequential vapor deposition process in the prior art are solved, and the perovskite double-layer film has excellent photoelectric properties and surface characteristics.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor materials and optoelectronic technologies, and particularly relates to a method for patterning the preparation of an all-inorganic metal halide perovskite double-layer film. Background Art

[0002] Metal halide perovskites combine the characteristics of high carrier mobility of inorganic semiconductors and easy processing of organic semiconductors, and at the same time have advantages such as low cost, high luminous efficiency, and high color purity, making them an ideal choice for the active layer of micro light-emitting diodes. At present, the external quantum efficiency of light-emitting diodes based on metal halide semiconductors has exceeded 30% in multiple bands. However, almost all high-performance perovskite light-emitting diodes (PeLEDs) are based on the solution spin-coating method, which limits the production efficiency of PeLEDs. More importantly, it faces a daunting challenge to integrate micro PeLEDs of different colors on the same substrate. Therefore, developing a process for quickly integrating micro PeLEDs of different emission colors will help to promote the process of their industrial application.

[0003] Currently, the academic community has developed various construction methods for micro perovskite LEDs, including photolithography, printing, etching, mask-assisted deposition, nanoimprinting, transfer printing, and substrate pre-patterning. Among them, photolithography, etching, nanoimprinting, and substrate pre-patterning methods can obtain high-precision patterns, but they cannot directly integrate perovskites of different components onto the same substrate, so their application scope is limited; printing and transfer printing can integrate multiple perovskite components, but there are problems of low production efficiency; mask-assisted deposition uses a micro-patterned metal mask to control the position of gas molecules on the substrate, and can quickly and accurately prepare a patterned perovskite double-layer film; in addition, this process is compatible with mature OLED production lines, reducing the threshold for its practical application.

[0004] Template-assisted vapor deposition can be achieved in various ways. It can be classified into single-source deposition, sequential deposition, and multi-source deposition according to the number of evaporation sources used simultaneously. In single-source deposition, the perovskite precursor or pre-synthesized perovskite is placed in a crucible, and the material is deposited on the substrate by rapid gasification. This method cannot precisely control the perovskite composition, and the prepared thin film has poor optoelectronic properties. In multi-source thermal evaporation, the perovskite precursor components are placed in separate crucibles, and then the precursors are gasified separately. These precursor molecules are deposited on the substrate simultaneously. The advantage of this method is that the precursor components are evenly mixed, the components can be precisely controlled, and the prepared thin film has good optoelectronic properties. The disadvantage is poor controllability. Sequential vapor deposition is to deposit the perovskite precursor components on the substrate one by one and form perovskite through thermal diffusion. The advantage of this method is that only one evaporation source needs to be controlled at a time, and the controllability is relatively high. The disadvantage is that the diffusion length of the solid-phase multi-layer precursor thin film is limited. Therefore, the optoelectronic properties of the prepared thin film are between single-source deposition and multi-source deposition. In addition, none of the above three methods can introduce liquid or thermally decomposable materials into the perovskite to improve the optoelectronic and surface properties. Summary of the Invention

[0005] The object of the present invention is to provide a method for patterning the preparation of a double-layer film of all-inorganic metal halide perovskite to solve the technical problems of insufficient ion diffusion length and limited introduction of additives in the existing sequential vapor deposition process, thereby improving the optoelectronic and surface properties.

[0006] To achieve the above object, the present invention adopts the following technical solutions: In the first aspect, the present invention provides a method for patterning the preparation of a double-layer film of all-inorganic metal halide perovskite, including: Dissolve the first halide and alkaline earth metal halide salt in DMSO, heat and stir until completely dissolved to obtain solution A; spin-coat solution A on the surface of substrate A to obtain substrate B; deposit the second halide on the surface of substrate B through a patterned metal mask to obtain a perovskite double-layer film; Wherein, the first halide is cesium halide or lead halide; the second halide is cesium halide or lead halide; the first halide is different from the second halide; the alkaline earth metal halide salt is AEHA2, where AE is Ba or Sr, and HA is I, Br or Cl.

[0007] Preferably, when the first halide is lead halide and the second halide is cesium halide, the ratio of the sum of the molar amounts of the first halide and the alkaline earth metal halide salt to the molar amount of the second halide is 1:1; when the first halide is cesium halide and the second halide is lead halide, the molar ratio of the first halide, the second halide, and the alkaline earth metal halide salt is 1:1:0.

[0008] Preferably, the molar ratio of the first halide, tetraphenylphosphonium halide, and polyoxyethylene sorbitan monolaurate is 1:(0-1):(0-1).

[0009] Preferably, the substrate A is a plastic film, a metal sheet, or a glass sheet.

[0010] Preferably, the substrate A is modified with an alkali metal halide before use.

[0011] Preferably, the obtained perovskite double-layer film is subjected to thermal annealing treatment.

[0012] In a second aspect, the present invention provides an all-inorganic metal halide perovskite double-layer film prepared by the above preparation method.

[0013] Preferably, the chemical formula of the perovskite double-layer film is CsPb (1-x) AE x (M (1-y) HA y )3; where AE is Ba or Sr; M is the halogen in the halide, M is I, Br, or Cl; HA is I, Br, or Cl; 0 ≤ x < 1; 0 ≤ y < 1.

[0014] In a third aspect, the present invention provides an application of the all-inorganic metal halide perovskite double-layer film in the technical field of light-emitting diode preparation.

[0015] Preferably, the perovskite double-layer film is used as a light-emitting medium of a light-emitting diode.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a patterning preparation method and application of an all-inorganic metal halide perovskite double-layer film. The chemical formula of the perovskite double-layer film is CsPb (1-x) AE x (M (1-y) HA y )3; where AE is Ba or Sr; M is the halogen in the halide, M is I, Br, or Cl; HA is I, Br, or Cl; 0 ≤ x < 1; 0 ≤ y < 1. The present invention can conveniently add various liquid, high melting point, or easily thermally decomposed materials by spin-coating the solution, which is beneficial to suppressing perovskite crystal defects and endowing the material with high photoluminescence performance. The deposition of the second halide through a patterned metal mask can precisely control the shape and thickness of the deposited film, so that high coverage, patterning, and miniaturization of the film on the substrate can be achieved. Since the deposition of the perovskite precursor and the formation of the perovskite structure are carried out in steps, it is expected to realize the integration of patterned films of multiple colors (components) on the same substrate. The film prepared by the present invention has excellent optoelectronic properties and surface characteristics, is suitable for the active layer of a light-emitting diode, and has been applied. Brief Description of the Drawings

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0018] Figure 1 Schematic diagram of the sequential continuous deposition process of the perovskite double-layer film of the present invention; Figure 2 Spectrogram of the perovskite double-layer film of Examples 7 and 8; Figure 3 Scanning electron microscope images of the perovskite double-layer film of Examples 7 and 8; Figure 4 Structural diagrams of the light-emitting diode devices in Examples 7-11 and Example 13; Figure 5 Energy level diagrams of the light-emitting diode devices in Examples 7-9 and Example 13, and the transport layers except the perovskite layer in Examples 7-8; Figure 6 Optical picture of the perovskite double-layer film of Example 1 under excitation by a 365 nm ultraviolet lamp; Figure 7 Optical picture of the perovskite double-layer film of Example 1 under excitation by a 365 nm ultraviolet lamp; Figure 8 Optical picture of the perovskite double-layer film of Example 1 under excitation by a 365 nm ultraviolet lamp; Figure 9 Spectrogram of the light-emitting diode device in Example 7; Figure 10 Spectrogram of the light-emitting diode device in Example 8; Figure 11 Spectrogram of the light-emitting diode device in Example 9; Figure 12 Spectrogram of the light-emitting diode device in Example 10; Figure 13 Spectrogram of the light-emitting diode device in Example 11; Figure 14 Picture of the light-emitting diode device in Example 12 under electrical excitation; Figure 15 Spectrogram of the light-emitting diode device in Example 13. Detailed Description of the Embodiments

[0019] To enable those skilled in the art to understand the features and effects of the present invention, the following provides a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein shall have the ordinary meanings understood by those skilled in the art with respect to the present invention. In case of conflict, the definitions in this specification shall prevail.

[0020] The theories or mechanisms described and disclosed herein, whether correct or incorrect, shall in no way limit the scope of the present invention, that is, the content of the present invention can be implemented without being limited by any specific theory or mechanism.

[0021] In this document, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are only for the sake of brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be regarded as having covered and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0022] In this document, unless otherwise specified, the terms "comprising", "including", "containing", "having", or similar expressions cover the meanings of "consisting of" and "consisting essentially of". For example, "A comprises a" covers the meanings of "A comprises a and others" and "A consists only of a".

[0023] In this document, for the sake of concise description, all possible combinations of all technical features in each embodiment or example are not described. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each embodiment or example can be combined arbitrarily, and all possible combinations should be considered as within the scope described in this specification.

[0024] The following further describes the present invention in detail with reference to the accompanying drawings: The first object of the present invention is to provide a patterning preparation method for a fully inorganic metal halide perovskite double-layer film, as Figure 1 shown, including: Dissolve the first halide, tetraphenylphosphonium halide, polyoxyethylene sorbitan monolaurate (Tween20), and alkaline earth metal halide salt in dimethyl sulfoxide (DMSO), heat and stir in an inert environment until completely dissolved to obtain solution A; under an inert environment, spin-coat solution A on the surface of substrate A to obtain substrate B; use physical vapor deposition to deposit the second halide vapor on the surface of substrate B through a patterned metal mask to obtain a perovskite double-layer film; wherein, the first halide is cesium halide or lead halide; the second halide is cesium halide or lead halide; the first halide is different from the second halide; the alkaline earth metal halide is AEHA2, where AE is Ba or Sr, and HA is I, Br, or Cl.

[0025] The present invention can inhibit the defects of the perovskite double-layer film by adding tetraphenylphosphonium halide, polyoxyethylene sorbitan monolaurate and alkaline earth metal halide salts; the preparation process of the perovskite double-layer film is sensitive to moisture and oxygen in the air. In particular, lead halide and cesium halide are prone to hydrolysis reactions in a humid environment. In an inert environment (such as nitrogen or argon atmosphere), it is possible to prevent the substances in the solution from reacting with the moisture in the air, thereby ensuring the quality of the film; heating and stirring can accelerate the dissolution process and ensure the uniformity of the solution. In addition, appropriate heating helps to remove impurities in the solvent and ensure the consistency and high quality of the final film. Spin coating is a commonly used method for preparing a uniform film. By controlling the spin coating speed and time, the thickness and uniformity of the film can be precisely adjusted.

[0026] Exemplarily, when the first halide is lead halide and the second halide is cesium halide, the molar sum of the first halide and the alkaline earth metal halide salt and the molar ratio of the second halide is 1:1; when the first halide is cesium halide and the second halide is lead halide, the molar ratio of the first halide, the second halide and the alkaline earth metal halide salt is 1:1:0.

[0027] Exemplarily, the molar ratio of the first halide, tetraphenylphosphonium halide and polyoxyethylene sorbitan monolaurate is 1:(0~1):(0~1). By adjusting the molar ratios of the above compounds, not only can the reaction rate, selectivity and product quality be optimized, but also the reaction conditions can be improved to a certain extent, enabling the reaction to proceed under mild conditions, reducing the occurrence of side reactions and enhancing the overall reaction efficiency.

[0028] The substrate A is a plastic film, a metal sheet or a glass sheet. Plastic films are suitable for technical fields with high requirements for portability, flexibility, low cost and insulation; metal sheets are suitable for technical fields with high requirements for electrical conductivity, thermal conductivity and mechanical strength; glass sheets are suitable for technical fields that require transparency, chemical stability, surface smoothness and high-temperature stability; in practice, according to specific application requirements, selecting a suitable substrate material can bring significant performance improvement and cost optimization.

[0029] The substrate A is modified with an alkali metal halide before use, which can improve the wettability of the solution A to the substrate, thereby reducing the defects of the perovskite double-layer film.

[0030] The obtained perovskite double-layer film is subjected to thermal annealing treatment, and further, solvent-assisted ion diffusion and grain growth are carried out in a closed space; specifically, a method of thermal annealing assisted by DMF solvent is adopted to promote the cross-interface diffusion of ions and grow into large-grain perovskite, generating a three-dimensional perovskite component. Among them, the annealing temperature is not higher than 150 °C, and the annealing temperature and annealing time are adjusted according to the thickness of the lead halide and cesium halide layers until the optical, electrical, and surface properties of the film reach the best.

[0031] The present invention first modifies the substrate with alkali metal halides; then, the precursor is deposited step by step using the solution method and the evaporation method in sequence. Among them, the solution method in the first step can introduce various liquid, low-melting-point, or thermally unstable additives, and the evaporation method in the second step can precisely control the morphology of the deposited film; finally, the precursor components are promoted to diffuse with each other and form large-grain perovskite through solvothermal annealing. Modifying the substrate with alkali metal halide salts and then alternately using the solution method and the evaporation method to prepare the precursor film. Since the solution method used can conveniently add various liquid, high-melting-point, or easily thermally decomposed materials, it is beneficial to inhibit the defects of perovskite crystals, making the material have high photoluminescence performance; since the evaporation method used can precisely control the shape and thickness of the deposited film, high coverage, patterning, and miniaturization of the film on the substrate can be achieved; since the deposition of the perovskite precursor and the formation of the perovskite structure are carried out step by step, the integration of patterned films of multiple colors and the application of devices can be achieved on the same substrate.

[0032] The second object of the present invention is to provide a fully inorganic metal halide perovskite double-layer film, and the chemical formula of the perovskite double-layer film is CsPb (1-x) AE x (M (1-y) HA y )3; where AE is Ba or Sr; M is the halogen in the halide, M is I, Br, or Cl; HA is I, Br, or Cl; 0 ≤ x < 1; 0 ≤ y < 1. The bandgap of the perovskite double-layer film is adjusted by controlling the chlorine content or bromine content to adjust the emission wavelength, from green (i.e., y = 0) to blue or red (i.e., y > 0 (chlorine or iodine)).

[0033] The third object of the present invention is to provide an application of a fully inorganic metal halide perovskite double-layer film in the technical field of light-emitting diode preparation. The perovskite double-layer film is used as the light-emitting medium of the light-emitting diode. The light-emitting diode sequentially includes a substrate (transparent glass), an anode (ITO), a hole transport layer (PEDOT:PSS), the perovskite double-layer film of the present invention, an electron transport layer (TPBi), and a cathode (LiF / Al) from bottom to top.

[0034] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0035] In the following embodiments, conventional instruments and equipment in the art are used. For the experimental methods without specific conditions noted in the following embodiments, they are usually carried out under conventional conditions or according to the conditions recommended by the manufacturer. In the following embodiments, various raw materials are used. Unless otherwise specified, commercially available products are used, and their specifications are conventional specifications in the art. In the specification of the present invention and the following embodiments, unless otherwise specified, "%" represents weight percentage, "parts" represents weight parts, and the ratio represents weight ratio.

[0036] Example 1 First, the surface of indium tin oxide (ITO) that has been ultrasonically cleaned with deionized water, acetone, anhydrous ethanol and treated by plasma is used. By using the spin-coating process, poly[3,4-ethylenedioxythiophene]: poly(4-styrenesulfonate) (PEDOT:PSS) thin films are prepared in an open air environment. After annealing process (annealing temperature 150 °C, annealing time 10 minutes), the preparation of the thin films is completed; secondly, the thin films are transferred to an inert environment (such as a nitrogen atmosphere), and on its surface, by using the spin-coating process, an alkali metal halide modification layer is prepared again. After annealing process (annealing temperature 100 °C, annealing time 10 minutes), the preparation of substrate A is completed; PbI2, PbBr2 and PbCl2 are respectively dissolved in DMSO, heated and stirred until completely dissolved to obtain solutions A1, A2 and A3; solutions A1, A2 and A3 are respectively spin-coated on the surface of substrate A to obtain substrates B1, B2 and B3; CsI, CsBr and CsCl are respectively deposited on the surfaces of substrates B1, B2 and B3 through a patterned metal mask to obtain perovskite double-layer films; among them, the molar ratio of PbI2 to CsI, PbBr2 to CsBr and PbCl2 to CsCl is all 1:1, and the chemical formulas of the obtained perovskite double-layer films are CsPbI3, CsPbBr3 and CsPbCl3 respectively.

[0037] The color of the prepared perovskite double-layer film is determined by the components of the perovskite and is achieved by changing the halogen in the lead halide. As Figure 6(a), (b), and (c) are the excitation images of the red, green, and blue thin films obtained by spin-coating PbI2, PbBr2, and PbCl2, respectively. Among them, the size of the prepared thin film is determined by the size of the substrate. Figure 6 (a), Figure 6 (b), and Figure 6 (c) are all substrates of 5 * 5 cm; Figure 6 (d) is a substrate of 10 * 10 cm. Figure 7 (a), Figure 7 (b), and Figure 7 (c) are the red, green, and blue images of the bilateral letter AHUT patterns obtained by spin-coating PbI2, PbBr2, and PbCl2 under ultraviolet light excitation, respectively; the pattern of the prepared thin film is determined by the pattern of the mask; Figure 7 (d) is the green image of a regular rectangular array under ultraviolet light excitation; the area of the prepared thin film is determined by the pattern of the mask. Figure 8 (a) is the green image of a regular circular array with a diameter of 250 um under ultraviolet light excitation. Figure 8 (b) is a partial enlarged view of 8(a), that is, the green image under ultraviolet light excitation observed through the microscope field of view.

[0038] Example 2 First, the ITO surface ultrasonically cleaned with deionized water, acetone, and absolute ethanol and then treated by plasma was used. By using the spin-coating process, a PEDOT:PSS thin film was prepared in an open air environment. After the annealing process (annealing temperature: 140 °C, annealing time: 15 minutes), the thin film preparation was completed. Secondly, the thin film was transferred to an inert environment (such as a nitrogen atmosphere), and on its surface, by using the spin-coating process, an alkali metal halide modification layer was prepared. After the annealing process (annealing temperature: 100 °C, annealing time: 15 minutes), the preparation of substrate A was completed. CsI, CsBr, and CsCl were respectively dissolved in DMSO, heated and stirred until completely dissolved to obtain solutions A1, A2, and A3. Solutions A1, A2, and A3 were respectively spin-coated on the surface of substrate A to obtain substrates B1, B2, and B3. PbI2, PbBr2, and PbCl2 were respectively deposited on the surfaces of substrates B1, B2, and B3 through a patterned metal mask to obtain perovskite double-layer thin films. Among them, the molar ratios of CsI to PbI2, CsBr to PbBr2, and CsCl to PbCl2 are all 1:1, and the chemical formulas of the obtained perovskite double-layer thin films are CsPbI3, CsPbBr3, and CsPbCl3, respectively.

[0039] Example 3 First, the ITO surface that has been ultrasonically cleaned with deionized water, acetone, and absolute ethanol and treated with plasma is used. By using the spin-coating process, a PEDOT:PSS thin film is prepared in an open-air environment. After annealing (annealing temperature: 130 °C, annealing time: 20 minutes), the preparation of the thin film is completed. Secondly, the thin film is transferred to an inert environment (such as a nitrogen atmosphere), and on its surface, by using the spin-coating process, an alkali metal halide modification layer is prepared again. After annealing (annealing temperature: 90 °C, annealing time: 20 minutes), the preparation of substrate A is completed; As Figure 1 shown, PbBr2, tetraphenylphosphonium bromide (TPPB), polyoxyethylene sorbitan monolaurate, and BaBr2 are dissolved in DMSO, heated and stirred until completely dissolved to obtain solution A. Solution A is spin-coated and distributed on the surface of substrate A to obtain substrate B. CsBr is deposited on the surface of substrate B through a patterned metal mask to obtain a perovskite double-layer film. Among them, the molar ratio of PbBr2, tetraphenylphosphonium bromide, and polyoxyethylene sorbitan monolaurate is 1:0.5:1; the ratio of the sum of the molar numbers of PbBr2 and BaBr2 to the molar number of CsBr is 1:1, and the molar ratio of PbBr2 and BaBr2 is 1:1. The chemical formula of the obtained perovskite double-layer film is CsPb 1 / 2 Ba 1 / 2 Br3.

[0040] Example 4 First, the ITO surface that has been ultrasonically cleaned with deionized water, acetone, and absolute ethanol and treated with plasma is used. By using the spin-coating process, a PEDOT:PSS thin film is prepared in an open-air environment. After annealing (annealing temperature: 150 °C, annealing time: 10 minutes), the preparation of the thin film is completed. Secondly, the thin film is transferred to an inert environment (such as a nitrogen atmosphere), and on its surface, by using the spin-coating process, an alkali metal halide modification layer is prepared again. After annealing (annealing temperature: 100 °C, annealing time: 10 minutes), the preparation of substrate A is completed; PbI2, tetraphenylphosphonium chloride, polyoxyethylene sorbitan monolaurate, and SrCl2 are dissolved in DMSO, heated and stirred until completely dissolved to obtain solution A. Solution A is spin-coated and distributed on the surface of substrate A to obtain substrate B. CsI is deposited on the surface of substrate B through a patterned metal mask to obtain a perovskite double-layer film. Among them, the molar ratio of PbI2, tetraphenylphosphonium chloride, and polyoxyethylene sorbitan monolaurate is 1:1:0.5; the ratio of the sum of the molar numbers of PbI2 and SrCl2 to the molar number of CsBr is 1:1, and the molar ratio of PbI2 and SrCl2 is 1:9. The chemical formula of the obtained perovskite double-layer film is CsPb 1 / 10 Sr 9 / 10 (I 2 / 5Cl 3 / 5 )3.

[0041] Example 5 First, the ITO surface after ultrasonic cleaning with deionized water, acetone, and absolute ethanol and plasma treatment is used. Using the spin-coating process, a PEDOT:PSS thin film is prepared in an open air environment. After the annealing process (annealing temperature 150 °C, annealing time 10 minutes), the thin film preparation is completed. Secondly, the thin film is transferred to an inert environment (such as a nitrogen atmosphere), and on its surface, using the spin-coating process, an alkali metal halide modification layer is prepared again. After the annealing process (annealing temperature 100 °C, annealing time 10 minutes), the preparation of substrate A is completed; PbCl2, tetraphenylphosphonium iodide, polyoxyethylene sorbitan monolaurate, and SrI2 are dissolved in DMSO, heated and stirred until completely dissolved to obtain solution A; solution A is spin-coated and distributed on the surface of substrate A to obtain substrate B; CsCl2 is deposited on the surface of substrate B through a patterned metal mask to obtain a perovskite double-layer thin film; among them, the molar ratio of PbCl2, tetraphenylphosphonium iodide, and polyoxyethylene sorbitan monolaurate is 1:0.8:0.1; the ratio of the sum of the molar numbers of PbCl2 and SrI2 to the molar number of CsCl2 is 1:1, and the molar ratio of PbCl2 and SrI2 is 9:1. The chemical formula of the obtained perovskite double-layer thin film is CsPb 9 / 10 Sr 1 / 10 (Cl 14 / 15 I 1 / 15 )3.

[0042] Example 6 First, the ITO surface after ultrasonic cleaning with deionized water, acetone, and absolute ethanol and plasma treatment is used. Using the spin-coating process, a PEDOT:PSS thin film is prepared in an open air environment. After the annealing process (annealing temperature 150 °C, annealing time 10 minutes), the thin film preparation is completed. Secondly, the thin film is transferred to an inert environment (such as a nitrogen atmosphere), and on its surface, using the spin-coating process, an alkali metal halide modification layer is prepared again. After the annealing process (annealing temperature 100 °C, annealing time 10 minutes), the preparation of substrate A is completed; Dissolve PbCl2, tetraphenylphosphonium iodide, polyoxyethylene sorbitan monolaurate, and SrI2 in DMSO, heat and stir until completely dissolved to obtain Solution A; spin-coat Solution A on the surface of Substrate A to obtain Substrate B; deposit CsCl2 on the surface of Substrate B through a patterned metal mask to obtain a perovskite double-layer film; wherein, the molar ratio of PbCl2, tetraphenylphosphonium iodide, and polyoxyethylene sorbitan monolaurate is 1:0.4:0.9; the ratio of the sum of the molar amounts of PbCl2 and SrI2 to the molar amount of CsCl2 is 1:1, and the molar ratio of PbCl2 to SrI2 is 7:3. The chemical formula of the obtained perovskite double-layer film is CsPb 7 / 10 Sr 3 / 10 (Cl 4 / 5 I 1 / 5 )3。

[0043] Example 7 A light-emitting diode device with a green light-emitting all-inorganic perovskite as the active layer. The complete preparation process of the device is as follows: First, ultrasonically clean the surface of ITO treated by deionized water, acetone, and absolute ethanol and then treated by plasma, and use the spin-coating process to prepare a PEDOT:PSS film in an open air environment. After annealing (annealing temperature 150 °C, annealing time 10 minutes), the film preparation is completed; Secondly, transfer the film to an inert environment (such as a nitrogen atmosphere), and use the spin-coating process to prepare a lead bromide film on its surface; Then, transfer the film to a high-vacuum evaporation chamber, and deposit cesium bromide vapor with a thickness of 20 nm through a mask of normal size; Finally, thermally anneal the precursor film (annealing temperature 120 degrees Celsius, annealing time 5 min) to complete the film construction. Then, transfer the perovskite double-layer film to a high-vacuum evaporation chamber, and use thermal evaporation to sequentially prepare triphenylbenzothiophene (TPBi), LiF, and Al with the required thicknesses. The effective area of the light-emitting device is determined by the cross-sectional area of the Al electrode and the ITO. Finally, place the light-emitting device on the top of an integrating sphere, apply a voltage to both ends of the device and inject current using a source meter; collect the number of photons after diffuse reflection by the integrating sphere using a spectrometer, record the changes of current and the number of photons with voltage, and obtain parameters such as external quantum efficiency, luminance, emission peak, CIE, and current efficiency that characterize the device performance based on the assumption that the light-emitting device is a Lambertian body.

[0044] The absorption spectrum and steady-state photoluminescence spectrum of the film are as shown in Figure 2 (a)and Figure 2 (b)in the conventional annealing (Normal annealing) curve, that is, solvent-free annealing; the SEM images of the film are as shown in Figure 3 (a) and Figure 3 (c), whereFigure 3 (a) and Figure 3 (c) are the scanning electron microscope images of the perovskite double - layer thin films under low - magnification and high - magnification in the case of conventional annealing, respectively. The device structure of the light - emitting diode is as Figure 4 shown; the energy - level structure of the transport layer except for the perovskite layer is as Figure 5 shown; the performance of the light - emitting diode device based on the grown thin film is as Figure 9 shown, Figure 9 (a) is the external quantum efficiency - current density graph, Figure 9 (b) The left and right curves are the current density - voltage graph and the luminance - voltage graph respectively, Figure 9 (c) is the normalized electroluminescence spectrum at the maximum luminance.

[0045] Example 8 A light - emitting diode device with a solvent - annealed green - light all - inorganic perovskite double - layer thin film as the active layer. The complete device preparation process is as follows: First, the ITO surface ultrasonically cleaned with deionized water, acetone, and absolute ethanol and then treated by plasma is used. By using the spin - coating process, a PEDOT:PSS thin film is prepared in an open - air environment, and the film preparation is completed after annealing (annealing temperature 150 °C, annealing time 10 minutes); Second, the film is transferred to an inert environment (such as a nitrogen atmosphere), and on its surface, a lead bromide thin film is prepared by using the spin - coating process; Then, the film is transferred to a high - vacuum evaporation chamber, and cesium bromide vapor is deposited through a mask template of normal size with a thickness of 20 nm; Finally, the precursor thin film is thermally annealed in a DMF atmosphere (annealing temperature 120 degrees Celsius, annealing time 5 min) to complete the film construction. Then, the perovskite double - layer thin film is transferred to a high - vacuum evaporation chamber, and TPBi, LiF, and Al with the required thicknesses are sequentially prepared by thermal evaporation. The effective area of the light - emitting device is determined by the cross - sectional area of the Al electrode and the ITO. Finally, the light - emitting device is placed at the top of an integrating sphere, and a source meter is used to apply a voltage across the device and inject current; A spectrometer is used to collect the number of photons diffusely reflected by the integrating sphere, record the changes of current and the number of photons with voltage, and according to the assumption that the light - emitting device is a Lambertian body, parameters such as external quantum efficiency, luminance, emission peak, CIE, and current efficiency characterizing the device performance are obtained.

[0046] The corresponding energy - level structure is as Figure 5 shown; the performance of the light - emitting diode device based on the grown thin film is as Figure 10 shown, Figure 10 (a) is the external quantum efficiency - current density graph, Figure 10 (b) The left and right curves are the current density - voltage graph and the luminance - voltage graph respectively, Figure 10 (c) is the normalized electroluminescence spectrum at the maximum luminance.. The absorption spectrum and steady - state photoluminescence spectrum of the thin film are asFigure 2 (a) and Figure 2 shown in the solvent annealing curves in (b). The SEM images of the thin films are as Figure 3 (b) and Figure 3 (d). Figure 3 (b) and Figure 3 (d) are the scanning electron microscope images of the perovskite double - layer thin films under solvent annealing at low magnification and high magnification respectively. The device structure of the light - emitting diode is as Figure 4 shown; the energy - level structure of the transport layer except for the perovskite layer is as Figure 5 shown. Example 9 First, the ITO surface that has been ultrasonically cleaned with deionized water, acetone, and absolute ethanol and treated by plasma is used. By using the spin - coating process, PEDOT:PSS thin films are prepared in an open - air environment. After the annealing process (annealing temperature 150 °C, annealing time 10 minutes), the thin - film preparation is completed. Secondly, the thin film is transferred to an inert environment (such as a nitrogen atmosphere), and on its surface, a cesium bromide modification layer is prepared by using the spin - coating process. After the annealing process (annealing temperature 100 °C, annealing time 10 minutes), the thin - film preparation is completed. Then, on its surface, a lead bromide thin film is prepared by using the spin - coating process. Then, the thin film is transferred to a high - vacuum evaporation chamber, and cesium bromide vapor is deposited through a mask template of normal size to a thickness of 20 nm. Finally, the precursor thin film is thermally annealed in a DMF atmosphere (annealing temperature 120 °C, annealing time 5 min) to complete the thin - film construction.

[0047] For a light - emitting diode device with an interface - modified green - light all - inorganic perovskite double - layer thin film as the active layer, specifically: The perovskite double - layer thin film is transferred to a high - vacuum evaporation chamber, and TPBi, LiF, and Al with the required thicknesses are sequentially prepared by thermal evaporation. The effective area of the light - emitting device is determined by the cross - sectional area of the Al electrode and the ITO. Finally, the light - emitting device is placed at the top of an integrating sphere, and a voltage is applied to both ends of the device and current is injected using a source meter; the number of photons after diffuse reflection by the integrating sphere is collected using a spectrometer, and the changes of current and the number of photons with voltage are recorded. According to the assumption that the light - emitting device is a Lambertian body, parameters such as external quantum efficiency, luminance, emission peak, CIE, and current efficiency that characterize the device performance are obtained.

[0048] The absorption spectrum and steady - state photoluminescence spectrum of the thin film are as Figure 2 shown by the circular - marked curves; the SEM images of the thin film are as Figure 3 (b) and 3(d). The device structure of the light - emitting diode is as Figure 4 shown; the energy - level structure of the transport layer except for the perovskite layer is as Figure 5As shown; the performance of the light-emitting diode device based on the grown thin film is as Figure 11 shown, Figure 11 (a) is the external quantum efficiency-current density graph, Figure 11 (b) The left curve and the right curve are the current density-voltage graph and the luminance-voltage graph respectively, Figure 11 (c) is the normalized electroluminescence spectrum at the maximum luminance.

[0049] Example 10 First, the ITO surface after ultrasonic cleaning with deionized water, acetone, and absolute ethanol and plasma treatment is prepared with PEDOT:PSS thin film in an open air environment using the spin coating process. The film preparation is completed by annealing process (annealing temperature 150 °C, annealing time 10 minutes); secondly, the film is transferred to an inert environment (such as nitrogen atmosphere), and on its surface, a cesium bromide modification layer is prepared using the spin coating process, and the film preparation is completed by annealing process (annealing temperature 100 degrees Celsius, annealing time 10 minutes); then, on its surface, a lead iodide thin film is prepared using the spin coating process; then, the film is transferred to a high-vacuum evaporation chamber, and cesium bromide vapor is deposited through a normal-sized mask template with a thickness of 20 nm; finally, the precursor film is thermally annealed in a DMF atmosphere (annealing temperature 120 degrees Celsius, annealing time 5 min) to complete the film construction.

[0050] For a light-emitting diode device with an interface-modified red light all-inorganic perovskite double-layer thin film as the active layer, specifically: the perovskite double-layer thin film is transferred to a high-vacuum evaporation chamber, and TPBi, LiF, and Al with the required thicknesses are sequentially prepared by thermal evaporation. The effective area of the light-emitting device is determined by the cross-sectional area of the Al electrode and the ITO. Finally, the light-emitting device is placed at the top of the integrating sphere, and a voltage is applied to both ends of the device and a current is injected using a source meter; the number of photons after diffuse reflection by the integrating sphere is collected using a spectrometer, and the changes of current and photon number with voltage are recorded. According to the assumption that the light-emitting device is a Lambertian body, parameters such as external quantum efficiency, luminance, emission peak, CIE, and current efficiency characterizing the device performance are obtained.

[0051] The device structure of the light-emitting diode is as Figure 4 shown; the energy level structure except for the light-emitting layer is as Figure 5 shown; the performance of the light-emitting diode device based on the grown thin film is as Figure 12 shown, Figure 12 (a) is the external quantum efficiency-current density graph, Figure 12 (b) The left curve and the right curve are the current density-voltage graph and the luminance-voltage graph respectively, Figure 12 (c) is the normalized electroluminescence spectrum at the maximum luminance.

[0052] Example 11 First, the ITO surface after ultrasonic cleaning with deionized water, acetone, and absolute ethanol and plasma treatment was used. By means of the spin-coating process, a PEDOT:PSS thin film was prepared in an open air environment. After the annealing process (annealing temperature: 150 °C, annealing time: 10 minutes), the preparation of the thin film was completed. Secondly, the thin film was transferred to an inert environment (such as a nitrogen atmosphere), and on its surface, by means of the spin-coating process, a cesium bromide modification layer was prepared. After the annealing process (annealing temperature: 100 °C, annealing time: 10 minutes), the preparation of the thin film was completed. Then, on its surface, by means of the spin-coating process, a lead bromide and lead chloride (for sky blue light) or lead chloride (for blue light) thin film was prepared. Then, the thin film was transferred to a high-vacuum evaporation chamber, and cesium bromide vapor was deposited through a normal-sized mask template with a thickness of 20 nm. Finally, the precursor thin film was thermally annealed in a DMF atmosphere (annealing temperature: 120 °C, annealing time: 5 min) to complete the construction of the thin film.

[0053] For a light-emitting diode device using the interface-modified sky blue light and blue light all-inorganic perovskite double-layer thin film of this embodiment as the active layer, specifically: the perovskite double-layer thin film was transferred to a high-vacuum evaporation chamber, and by means of thermal evaporation, TPBi, LiF, and Al with the required thicknesses were sequentially prepared. The effective area of the light-emitting device was determined by the cross-sectional area of the Al electrode and the ITO. Finally, the light-emitting device was placed at the top of an integrating sphere, and a source meter was used to apply a voltage and inject current to both ends of the device; a spectrometer was used to collect the number of photons after diffuse reflection by the integrating sphere, and the changes in current and the number of photons with voltage were recorded. Based on the assumption that the light-emitting device is a Lambertian body, parameters such as the external quantum efficiency, luminance, emission peak, CIE, and current efficiency characterizing the device performance were obtained.

[0054] The device structure of the light-emitting diode is as Figure 4 shown; the energy level structure except for the light-emitting layer is as Figure 5 shown; the performance of the light-emitting diode device based on the grown thin film is as Figure 13 shown, Figure 13 (a) is the external quantum efficiency - current density graph, Figure 13 (b) The left curve and the right curve are the current density - voltage graph and the luminance - voltage graph respectively, Figure 13 (c) is the normalized electroluminescence spectrum at the maximum luminance.

[0055] Example 12 First, ultrasonically clean the ITO surface treated by deionized water, acetone, and absolute ethanol and then by plasma treatment, and prepare a PEDOT:PSS thin film in an open air environment using a spin-coating process. Complete the preparation of the thin film through an annealing process (annealing temperature: 150 °C, annealing time: 10 minutes). Secondly, transfer the thin film to an inert environment (such as a nitrogen atmosphere), and prepare a cesium bromide modification layer on its surface using a spin-coating process. Complete the preparation of the thin film through an annealing process (annealing temperature: 100 °C, annealing time: 10 minutes). Then, prepare a lead bromide thin film on its surface using a spin-coating process. Next, transfer the thin film to a high-vacuum evaporation chamber, and deposit cesium bromide vapor with a thickness of 20 nm through a patterned mask. Finally, complete the construction of the thin film by thermally annealing the precursor thin film in a DMF atmosphere (annealing temperature: 120 °C, annealing time: 5 min).

[0056] For a light-emitting diode device and array using a patterned all-inorganic perovskite double-layer thin film of this embodiment as the active layer, specifically: transfer the perovskite double-layer thin film to a high-vacuum evaporation chamber, and sequentially prepare TPBi, LiF, and Al with required thicknesses using thermal evaporation. The effective area of the light-emitting device is determined by the cross-sectional area of the Al electrode and the ITO. Finally, place the light-emitting device at the top of an integrating sphere, apply a voltage across the device and inject current using a source meter; collect the number of photons diffusely reflected by the integrating sphere using a spectrometer, record the changes in current and the number of photons with voltage, and obtain parameters such as external quantum efficiency, luminance, emission peak, CIE, and current efficiency characterizing the device performance based on the assumption that the light-emitting device is a Lambertian body.

[0057] The device structure of the light-emitting diode is as Figure 4 shown; the corresponding energy level structure is as Figure 5 shown; the pictures of the device in the working state are as Figure 14 (a) and Figure 14 (b) shown, where Figure 14 (a) is the patterned device; Figure 14 (b) is the array device.

[0058] Example 13 A light-emitting diode device with a miniaturized all-inorganic perovskite double-layer film as the active layer. The complete device preparation process is as follows: First, the ITO surface that has been ultrasonically cleaned with deionized water, acetone, and absolute ethanol and then treated with plasma is used. Using the spin-coating process, a PEDOT:PSS film is prepared in an open-air environment. After the annealing process (annealing temperature 150 °C, annealing time 10 minutes), the film preparation is completed; Second, the film is transferred to an inert environment (such as a nitrogen atmosphere), and on its surface, using the spin-coating process, a cesium bromide modification layer is prepared. After the annealing process (annealing temperature 100 °C, annealing time 10 minutes), the film preparation is completed; Then, on its surface, using the spin-coating process, a lead bromide film is prepared; Then, the film is transferred to a high-vacuum evaporation chamber, and cesium bromide vapor is deposited through a patterned mask template to a thickness of 20 nm; Finally, the precursor film is thermally annealed in a DMF atmosphere (annealing temperature 120 °C, annealing time 5 min) to complete the film construction.

[0059] For the light-emitting diode device with a miniaturized all-inorganic perovskite double-layer film as the active layer in this embodiment, specifically: The perovskite double-layer film is transferred to a high-vacuum evaporation chamber, and using thermal evaporation, TPBi, LiF, and Al with the required thicknesses are sequentially prepared. The effective area of the light-emitting device is determined by the cross-sectional area of the Al electrode and the ITO. Finally, the light-emitting device is placed at the top of an integrating sphere, and a source meter is used to apply a voltage and inject current to both ends of the device; A spectrometer is used to collect the number of photons after diffuse reflection by the integrating sphere, and the changes in current and the number of photons with voltage are recorded. Based on the assumption that the light-emitting device is a Lambertian body, parameters such as external quantum efficiency, luminance, emission peak, CIE, and current efficiency that characterize the device performance are obtained.

[0060] The device structure of the light-emitting diode is as Figure 4 shown, and the energy level structure of the transport layer except for the perovskite layer is as Figure 5 shown; The performance of the light-emitting diode device based on the grown film is as Figure 15 shown, Figure 15 (a) is the external quantum efficiency-current density graph, Figure 15 (b) The left curve and the right curve are the current density-voltage graph and the luminance-voltage graph respectively, Figure 15 (c) is the normalized electroluminescence spectrum at the maximum luminance, Figure 15 (d) is the green image under ultraviolet lamp excitation observed through the microscope field of view of the circular matrix.

[0061] In Figure 4Among them, ITO serves as the transparent conductive electrode, PEODT:PSS serves as the hole transport / electron blocking layer, and the perovskite is specifically cesium lead bromide chloride all-inorganic perovskite with different chlorine and iodine contents, serving as the light-emitting layer; TPBi serves as the electron transport / hole blocking layer; LiF serves as the electrode modification layer, and Al serves as the counter electrode.

[0062] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, various changes and modifications can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A patterning preparation method for an all-inorganic metal halide perovskite double-layer film, characterized in that, Comprising: Dissolve the first halide, tetraphenylphosphonium halide, polyoxyethylene sorbitan monolaurate, and alkaline earth metal halide salt in DMSO, heat and stir until completely dissolved to obtain solution A; Spin-coat solution A on the surface of substrate A to obtain substrate B; deposit the second halide on the surface of substrate B through a patterned metal mask to obtain a perovskite double-layer film; Wherein, the first halide is cesium halide or lead halide; the second halide is cesium halide or lead halide; the first halide is different from the second halide; the alkaline earth metal halide salt is AEHA2, where AE is Ba or Sr, and HA is I, Br, or Cl.

2. The patterning preparation method of an all-inorganic metal halide perovskite double-layer film according to claim 1, wherein When the first halide is lead halide and the second halide is cesium halide, the ratio of the sum of the molar amounts of the first halide and the alkaline earth metal halide salt to the molar amount of the second halide is 1:1; when the first halide is cesium halide and the second halide is lead halide, the molar ratio of the first halide, the second halide, and the alkaline earth metal halide salt is 1:1:

0.

3. The patterning preparation method of a fully inorganic metal halide perovskite double-layer film according to claim 1, characterized in that, The molar ratio of the first halide, tetraphenylphosphonium halide, and polyoxyethylene sorbitan monolaurate is 1:(0~1):(0~1).

4. The patterned preparation method of a fully inorganic metal halide perovskite double-layer film according to claim 1, characterized in that, The substrate A is a plastic film, a metal sheet, or a glass sheet.

5. A patterning preparation method of an all-inorganic metal halide perovskite double-layer film according to claim 1, characterized in that The substrate A is modified with an alkali metal halide before use.

6. The patterned preparation method of a fully inorganic metal halide perovskite double-layer film according to claim 1, wherein Perform thermal annealing treatment on the obtained perovskite double-layer film.

7. A fully inorganic metal halide perovskite double-layer film, characterized in that, Prepared by using the preparation method according to any one of claims 1 to 7.

8. The all-inorganic metal halide perovskite double-layer film according to claim 7, wherein The chemical formula of the perovskite double-layer film is CsPb (1-x) AE x (M (1-y) HA y )3; where AE is Ba or Sr; M is a halogen in a halide, M is I, Br or Cl; HA is I, Br or Cl; 0 ≤ x < 1; 0 ≤ y < 1.

9. Use of an all-inorganic metal halide perovskite double-layer film according to claim 7 in the technical field of light-emitting diode preparation.

10. The application according to claim 9, wherein The perovskite double-layer film is used as a light-emitting medium for a light-emitting diode.

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