High-efficiency all-inorganic tin-based near-infrared perovskite light-emitting diode and preparation method thereof
Patent Information
- Application Number
- CN202510470229.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-15
- Publication Date
- 2025-07-15
Smart Images
Figure CN120322099A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of perovskite light-emitting device production, and specifically relates to a high-efficiency all-inorganic tin-based near-infrared perovskite light-emitting diode and a preparation method thereof. Background Art
[0002] Perovskite materials have become materials with great application potential in the optoelectronic field due to their low synthesis cost, high luminous efficiency, excellent color purity, and adjustable bandgap. As one of the representative applications of perovskite materials, perovskite light-emitting diodes (PeLEDs) can be prepared by simple solution processing techniques (such as spin coating, inkjet printing, etc.), which greatly simplifies the manufacturing process and has the potential for large-scale production. In addition, the high photoluminescence quantum yield and narrow emission full width at half maximum of perovskite materials show unique advantages in the fields of display and lighting. Initially, lead-based perovskites (such as MAPbI3, FAPbI3) became a research hotspot due to their excellent optoelectronic properties, and achieved an external quantum efficiency (EQE) of more than 20% in green, red, and blue PeLEDs. However, due to the toxicity of lead and the resulting environmental problems (such as soil and water pollution), researchers began to seek alternative solutions. Tin-based perovskites, as a new type of alternative material, have gradually become the focus of research due to their low toxicity (the degradation product is SnO2, which is harmless to the environment) and adjustable bandgap.
[0003] Significant progress has been made in the external quantum efficiency, preparation method innovation, and elimination of material defects of tin-based near-infrared perovskite light-emitting diodes. For example, the team of Xie Fengxian from Fudan University achieved a device with an EQE of 7.61% at an emission wavelength of 945 nm by optimizing the device structure and adding tin compensators (such as SnF2), creating a new record in this field. However, current research mainly relies on adding tin compensators (such as SnF2, SnCl2, etc.) to the precursor solution. These additives compensate for oxidation losses by providing additional Sn 2+ sources and partially passivate grain boundary defects. Nevertheless, the addition of tin compensators still has the following limitations: First, its introduction increases the process complexity, and precise control of the addition concentration (usually 5%-10% of the molar amount of SnI2) is required to ensure effective suppression of Sn 2+ oxidation without introducing excessive impurities; Second, the tin compensator may decompose or undergo side reactions with other components during high-temperature annealing, generating new impurities (such as SnF4, SnCl4, etc.), which may become non-radiative recombination centers and reduce the carrier lifetime.
[0004] Therefore, finding a preparation method for all-inorganic tin-based near-infrared perovskite light-emitting diodes that does not rely on tin compensators has become an important research direction in this field. Summary of the Invention
[0005] The object of the present invention is to provide a highly efficient all-inorganic tin-based near-infrared perovskite light-emitting diode and a preparation method thereof, so as to overcome the dependence on tin compensators in the preparation process of tin-based perovskite light-emitting diodes and achieve high-efficiency near-infrared light emission.
[0006] To achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a preparation method of a highly efficient all-inorganic tin-based near-infrared perovskite light-emitting diode, comprising the following steps: Mix the PSSNa solution and PEDOT:PSS to obtain a modified hole transport layer solution; spin-coat the modified hole transport layer solution on an ITO substrate, and form a modified hole transport layer after heating and annealing; Dissolve CsI, SnI2, L-tryptophan methyl ester hydrochloride, and RbSCN in a DMSO solvent, then add tin powder, and obtain a perovskite precursor solution after stirring; spin-coat the perovskite precursor solution on the modified hole transport layer, and form a perovskite thin film layer after heating and annealing; Under vacuum conditions, deposit TPBi on the perovskite thin film layer to form an electron transport layer, deposit LiF on the electron transport layer to form an electron injection layer, and deposit Al on the electron injection layer to form a cathode, thereby obtaining the all-inorganic tin-based perovskite light-emitting diode.
[0007] Preferably, the volume ratio of the PSSNa solution to PEDOT:PSS is (4-5):1; the concentration of the PSSNa solution is 20-25 mg / mL.
[0008] Preferably, the molar ratio of CsI, SnI2, L-tryptophan methyl ester hydrochloride, and RbSCN is 9:10:1:1.
[0009] Preferably, the mass fraction of the perovskite precursor solution is 12.5%.
[0010] Preferably, in the step of spin-coating the modified hole transport layer solution on the ITO substrate, the spin-coating conditions are: spin-coating at a speed of 4800-5200 rpm for 45-50 seconds.
[0011] Preferably, in the step of forming the modified hole transport layer after heating and annealing, the heating and annealing conditions are: annealing at 145-155 °C for 10-15 min.
[0012] Preferably, in the step of spin-coating the perovskite precursor solution on the modified hole transport layer, the spin-coating conditions are: spin-coating at a speed of 4800-5200 rpm for 55-60 seconds.
[0013] Preferably, in the step of forming the perovskite thin film by heating and annealing, the conditions for heating and annealing are: annealing at 110-120 °C for 10-15 min.
[0014] In a second aspect, the present invention provides a highly efficient all-inorganic tin-based near-infrared perovskite light-emitting diode; the light-emitting diode sequentially includes an anode, a modified hole transport layer, a perovskite thin film layer, an electron transport layer, an electron injection layer, and a cathode from bottom to top.
[0015] Preferably, the anode is made of an ITO substrate; the cathode is made of Al.
[0016] Compared with the prior art, the present invention has the following beneficial effects: Through the combination of PSSNa solution and PEDOT:PSS, the conductivity and interfacial properties of the hole transport layer are optimized; by using RbSCN and L-tryptophan methyl ester hydrochloride as additives, where Rb + fills the lattice vacancies, SCN - stabilizes Sn through strong coordination, 2+ while the amino and carboxylate groups of L-tryptophan methyl ester further inhibit Sn 2+ oxidation and passivate grain boundary defects, combined with the in-situ dynamic reduction protection of metallic tin powder in DMSO solvent, to form a highly pure and low-defect all-inorganic perovskite thin film layer, breaking through the technical bottleneck of traditional tin-based systems relying on additives such as SnCl2, avoiding toxic additives and improving material stability. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.
[0018] Figure 1 is a schematic structural diagram of a highly efficient all-inorganic tin-based near-infrared perovskite light-emitting diode of the present invention; Figure 2 is a current density-voltage-irradiance curve graph of the light-emitting diode prepared in Example 1 of the present invention; Figure 3 is an external quantum efficiency-current density curve graph of the light-emitting diode prepared in Example 1 of the present invention; Figure 4 is an electroluminescence spectrum graph of the light-emitting diode prepared in Example 1 of the present invention; Figure 5 is an SEM graph of a perovskite thin film prepared without any additives; Figure 6 SEM image of a perovskite film prepared by adding only L-tryptophan methyl ester hydrochloride; Figure 7 SEM image of a perovskite film prepared by adding L-tryptophan methyl ester hydrochloride and RbSCN.
[0019] In the figure, 1 is the anode; 2 is the modified hole transport layer; 3 is the perovskite film layer; 4 is the electron transport layer; 5 is the electron injection layer; 6 is the cathode. Detailed implementation manners
[0020] 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.
[0021] The theories or mechanisms described and disclosed herein, whether correct or incorrect, shall not limit the scope of the present invention in any way, that is, the content of the present invention can be implemented without being limited by any specific theory or mechanism.
[0022] In this article, 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 ranges (including integers and fractions).
[0023] In this article, 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".
[0024] In this article, for the sake of brevity of 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.
[0025] 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 preparation method of a highly efficient all-inorganic tin-based near-infrared perovskite light-emitting diode, which includes the following steps: Mix the poly(sodium 4-styrenesulfonate) (PSSNa) solution and PEDOT:PSS to obtain a modified hole transport layer solution; spin-coat the modified hole transport layer solution on the ITO substrate at a speed of 4800 - 5200 rpm for 45 - 50 seconds, and anneal it at 145 - 155 °C for 10 - 15 min to form a modified hole transport layer 2; Dissolve CsI, SnI2, L-tryptophan methyl ester hydrochloride and RbSCN in DMSO solvent, then add tin powder, and stir to obtain a perovskite precursor solution; spin-coat the perovskite precursor solution on the modified hole transport layer 2 at a speed of 4800 - 5200 rpm for 55 - 60 seconds, and anneal it at 110 - 120 °C for 10 - 15 min to form a perovskite thin film layer 3; Under vacuum conditions, deposit TPBi on the perovskite thin film layer 3 to form an electron transport layer 4, deposit LiF on the electron transport layer 4 to form an electron injection layer 5, and deposit Al on the electron injection layer 5 to form a cathode 6, thus obtaining the all-inorganic tin-based perovskite light-emitting diode.
[0026] The present invention provides a preparation method of an efficient all-inorganic tin-based near-infrared perovskite light-emitting diode without an additional tin compensator. Specifically, the present invention significantly optimizes the conductivity and interfacial properties of the hole transport layer through the combination of the PSSNa solution and PEDOT:PSS. The introduction of PSSNa not only improves the dispersion uniformity of PEDOT:PSS, but also reduces the hole injection barrier through the charge balance effect of the sulfonic acid groups, while enhancing the adhesion of the thin film to the ITO substrate and reducing the non-radiative recombination caused by interface defects; Secondly, in the preparation of the perovskite thin film layer 3, the present invention adopts a synergistic passivation strategy of RbSCN and L-tryptophan methyl ester hydrochloride, in which Rb + fills the lattice vacancies, SCN - stabilizes Sn through strong coordination, 2+ while the amino and carboxylate groups of L-tryptophan methyl ester further inhibit the oxidation of Sn 2+ and passivate the grain boundary defects. Combined with the in-situ dynamic reduction protection of metallic tin powder in DMSO solvent, a high-purity, low-defect all-inorganic perovskite thin film is formed, breaking through the technical bottleneck of the traditional tin-based system relying on additives such as SnCl2, avoiding toxic additives and improving the material stability. In addition, TPBi, as an efficient electron transport material, can effectively improve the electron transport efficiency, while LiF, as the electron transport layer 4, can reduce the injection resistance of electrons to the cathode 6, further improving the efficiency and stability of the device. Al, as the cathode material, can provide excellent current conductivity and form an effective interface with the electron transport layer 4, ensuring better current injection and stability during the operation of the device.
[0027] Among them, the volume ratio of the PSSNa solution to PEDOT:PSS is (4 - 5):1; the concentration of the PSSNa solution is 20 - 25 mg / mL. The PSSNa solution at this concentration ratio can provide a sufficient density of sulfonic acid groups, form a uniform negatively charged layer on the surface of the ITO substrate through electrostatic adsorption, reduce the barrier for holes to be injected from ITO into PEDOT:PSS, and at the same time its hydrophilic property improves the wettability of PEDOT:PSS on ITO, significantly enhancing the film thickness uniformity.
[0028] The molar ratio of CsI, SnI2, L-tryptophan methyl ester hydrochloride, and RbSCN is 9:10:1:1. This molar ratio can effectively balance the functions of each component, improving the overall optoelectronic performance of the perovskite material and the long-term stability of the device. Specifically, CsI and SnI2, as the perovskite precursors, can provide suitable crystal growth conditions, improve the crystal quality of the material, and thus enhance the optoelectronic performance of the device. L-tryptophan methyl ester hydrochloride, as an organic additive, helps to regulate the morphology and crystallization of the perovskite film, enhancing the film uniformity and stability. RbSCN can enhance the current conduction and stability of the device by optimizing the charge transport characteristics.
[0029] The mass fraction of the perovskite precursor solution is 12.5%. This mass fraction balances the solute concentration and the solvent evaporation kinetics, ensuring that the solution viscosity and surface tension are suitable during the spin-coating process, forming a perovskite film with uniform thickness and no pinholes, while avoiding problems such as too fast crystallization caused by high concentration or film discontinuity caused by low concentration.
[0030] The second object of the present invention is to provide a highly efficient all-inorganic tin-based near-infrared perovskite light-emitting diode. The light-emitting diode sequentially includes an anode 1, a modified hole transport layer 2, a perovskite thin film layer 3, an electron transport layer 4, an electron injection layer 5, and a cathode 6 from bottom to top. Among them, the anode 1 is made of an ITO substrate, and the cathode 6 is made of Al. The ITO substrate can provide excellent transparency and conductivity, facilitating the efficient transmission of current while reducing the light absorption loss. The modified hole transport layer 2 optimizes the hole injection and transport performance, enhances the recombination efficiency of electrons and holes, and improves the light-emitting efficiency. The perovskite thin film layer 3, as the light-emitting layer, can provide excellent light emission characteristics in the near-infrared band. The electron transport layer 4 and the electron injection layer 5 effectively regulate the electron injection and transport, reduce the carrier loss, and ensure the efficient operation of the device. The cathode 6 is made of Al material, providing excellent current conduction and ensuring the long-term stable operation of the device.
[0031] 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.
[0032] The following embodiments use conventional instruments and equipment in the art. 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. Various raw materials are used in the following embodiments. Unless otherwise stated, 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.
[0033] Example 1 Mix the PSSNa solution with a concentration of 25 mg / mL and PEDOT:PSS at a volume ratio of 5:1 to obtain a modified hole transport layer solution; spin-coat the modified hole transport layer solution on the ITO substrate at a speed of 4800 rpm for 50 seconds, and anneal it at 145 °C for 15 minutes to form a modified hole transport layer 2; Dissolve CsI, SnI2, L-tryptophan methyl ester hydrochloride, and RbSCN in a DMSO solvent at a molar ratio of 9:10:1:1, and then add an appropriate amount of tin powder. After stirring, a perovskite precursor solution with a mass fraction of 12.5% is obtained; spin-coat the perovskite precursor solution on the modified hole transport layer 2 at a speed of 4800 rpm for 60 seconds, and anneal it at 110 °C for 15 minutes to form a perovskite thin film layer 3; Under vacuum conditions, deposit TPBi on the perovskite thin film layer 3 to form an electron transport layer 4, deposit LiF on the electron transport layer 4 to form an electron injection layer 5, and deposit Al on the electron injection layer 5 to form a cathode 6, thus obtaining the all-inorganic tin-based perovskite light-emitting diode.
[0034] Example 2 Mix the PSSNa solution with a concentration of 25 mg / mL and PEDOT:PSS at a volume ratio of 5:1 to obtain a modified hole transport layer solution; spin-coat the modified hole transport layer solution on the ITO substrate at a speed of 5000 rpm for 48 seconds, and anneal it at 150 °C for 12 minutes to form a modified hole transport layer 2; CsI, SnI2, L-tryptophan methyl ester hydrochloride and RbSCN were dissolved in DMSO solvent at a molar ratio of 9:10:1:1, and an appropriate amount of tin powder was added. After stirring, a perovskite precursor solution with a mass fraction of 12.5% was obtained. The perovskite precursor solution was spin-coated on the modified hole transport layer 2 at a speed of 5000 rpm for 58 seconds, and annealed at 115 °C for 12 minutes to form a perovskite thin film layer 3; Under vacuum conditions, TPBi was evaporated onto the perovskite thin film layer 3 to form an electron transport layer 4, LiF was evaporated onto the electron transport layer 4 to form an electron injection layer 5, and Al was evaporated onto the electron injection layer 5 to form a cathode 6, obtaining the all-inorganic tin-based perovskite light-emitting diode.
[0035] Example 3 A PSSNa solution with a concentration of 23 mg / mL and PEDOT:PSS were mixed at a volume ratio of 5:1 to obtain a modified hole transport layer solution. The modified hole transport layer solution was spin-coated on the ITO substrate at a speed of 5200 rpm for 50 seconds, and annealed at 155 °C for 10 minutes to form a modified hole transport layer 2; CsI, SnI2, L-tryptophan methyl ester hydrochloride and RbSCN were dissolved in DMSO solvent at a molar ratio of 9:10:1:1, and an appropriate amount of tin powder was added. After stirring, a perovskite precursor solution with a mass fraction of 12.5% was obtained. The perovskite precursor solution was spin-coated on the modified hole transport layer 2 at a speed of 5200 rpm for 60 seconds, and annealed at 120 °C for 10 minutes to form a perovskite thin film layer 3; Under vacuum conditions, TPBi was evaporated onto the perovskite thin film layer 3 to form an electron transport layer 4, LiF was evaporated onto the electron transport layer 4 to form an electron injection layer 5, and Al was evaporated onto the electron injection layer 5 to form a cathode 6, obtaining the all-inorganic tin-based perovskite light-emitting diode.
[0036] Example 4 A PSSNa solution with a concentration of 21 mg / mL and PEDOT:PSS were mixed at a volume ratio of 4.5:1 to obtain a modified hole transport layer solution. The modified hole transport layer solution was spin-coated on the ITO substrate at a speed of 5200 rpm for 50 seconds, and annealed at 155 °C for 10 minutes to form a modified hole transport layer 2; CsI, SnI2, L-tryptophan methyl ester hydrochloride and RbSCN were dissolved in DMSO solvent at a molar ratio of 9:10:1:1, and an appropriate amount of tin powder was added. After stirring, a perovskite precursor solution with a mass fraction of 12.5% was obtained. The perovskite precursor solution was spin-coated on the modified hole transport layer 2 at a speed of 5000 rpm for 58 seconds, and annealed at 120 °C for 10 minutes to form a perovskite thin film layer 3; Under vacuum conditions, TPBi is evaporated onto the perovskite thin film layer 3 to form an electron transport layer 4, LiF is evaporated onto the electron transport layer 4 to form an electron injection layer 5, and Al is evaporated onto the electron injection layer 5 to form a cathode 6, thereby obtaining the all-inorganic tin-based perovskite light-emitting diode.
[0037] Example 5 A PSSNa solution with a concentration of 20 mg / mL and PEDOT:PSS are mixed at a volume ratio of 4:1 to obtain a modified hole transport layer solution; the modified hole transport layer solution is spin-coated on the ITO substrate at a speed of 5000 rpm for 50 seconds and annealed at 155 °C for 10 minutes to form a modified hole transport layer 2; CsI, SnI2, L-tryptophan methyl ester hydrochloride, and RbSCN are dissolved in DMSO solvent at a molar ratio of 9:10:1:1, and then an appropriate amount of tin powder is added. After stirring, a perovskite precursor solution with a mass fraction of 12.5% is obtained; the perovskite precursor solution is spin-coated on the modified hole transport layer 2 at a speed of 5200 rpm for 60 seconds and annealed at 120 °C for 10 minutes to form a perovskite thin film layer 3; Under vacuum conditions, TPBi is evaporated onto the perovskite thin film layer 3 to form an electron transport layer 4, LiF is evaporated onto the electron transport layer 4 to form an electron injection layer 5, and Al is evaporated onto the electron injection layer 5 to form a cathode 6, thereby obtaining the all-inorganic tin-based perovskite light-emitting diode.
[0038] The optoelectronic properties of the light-emitting diode device obtained in Example 1 of the present invention are tested, and the light-emitting area of the device is 0.04 mm²: As Figures 2 to 4 shown, the light-emitting diode prepared in Example 1 achieved an all-inorganic tin-based near-infrared perovskite light-emitting diode with an external quantum efficiency of 5.3% and an irradiance of 50 W sr -1 m -2 under the condition of not adding any tin compensator by introducing L-tryptophan methyl ester hydrochloride and RbSCN, and its electroluminescence peak is located at about 932 nm.
[0039] As Figures 5 to 7 shown, the present invention adds L-tryptophan methyl ester hydrochloride and RbSCN as additives, and the perovskite thin film prepared has a more regular grain morphology and is denser and more uniform compared to the perovskite thin film prepared without adding any additives and only adding L-tryptophan methyl ester hydrochloride.
[0040] 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, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A preparation method of an efficient all-inorganic tin-based near-infrared perovskite light-emitting diode, characterized in that, It includes the following steps: Mix the PSSNa solution and PEDOT:PSS to obtain a modified hole transport layer solution; Spin-coat the modified hole transport layer solution on the ITO substrate, and form a modified hole transport layer (2) after heating and annealing; Dissolve CsI, SnI2, L-tryptophan methyl ester hydrochloride and RbSCN in DMSO solvent, then add tin powder, and obtain a perovskite precursor solution after stirring; Spin-coat the perovskite precursor solution on the modified hole transport layer (2), and form a perovskite thin film layer (3) after heating and annealing; Under vacuum conditions, deposit TPBi on the perovskite thin film layer (3) to form an electron transport layer (4), deposit LiF on the electron transport layer (4) to form an electron injection layer (5), and deposit Al on the electron injection layer (5) to form a cathode (6), thereby obtaining the all-inorganic tin-based perovskite light-emitting diode.
2. The preparation method of an efficient all-inorganic tin-based near-infrared perovskite light-emitting diode according to claim 1, wherein, The volume ratio of the PSSNa solution to PEDOT:PSS is (4~5):1; the concentration of the PSSNa solution is 20~25 mg / mL.
3. The preparation method of an efficient all-inorganic tin-based near-infrared perovskite light-emitting diode according to claim 1, wherein, The molar ratio of CsI, SnI2, L-tryptophan methyl ester hydrochloride and RbSCN is 9:10:1:
1.
4. The preparation method of an efficient all-inorganic tin-based near-infrared perovskite light-emitting diode according to claim 1, characterized in that, The mass fraction of the perovskite precursor solution is 12.5%.
5. The preparation method of an efficient all-inorganic tin-based near-infrared perovskite light-emitting diode according to claim 1, wherein, In the step of spin-coating the modified hole transport layer solution on the ITO substrate, the spin-coating conditions are: spin-coating at a rotation speed of 4800~5200 rpm for 45~50 seconds.
6. The preparation method of an efficient all-inorganic tin-based near-infrared perovskite light-emitting diode according to claim 1, characterized in that, In the step of forming the modified hole transport layer (2) after heating and annealing, the heating and annealing conditions are: annealing at 145~155 °C for 10~15 min.
7. The preparation method of an efficient all-inorganic tin-based near-infrared perovskite light-emitting diode according to claim 1, wherein In the step of spin-coating the perovskite precursor solution on the modified hole transport layer (2), the spin-coating conditions are: spin-coating at a rotation speed of 4800~5200 rpm for 55~60 seconds.
8. The preparation method of an efficient all-inorganic tin-based near-infrared perovskite light-emitting diode according to claim 1, wherein In the step of forming the perovskite thin film after heating and annealing, the heating and annealing conditions are: annealing at 110~120 °C for 10~15 min.
9. An efficient all-inorganic tin-based near-infrared perovskite light-emitting diode, characterized in that, It is prepared by using the preparation method described in any one of claims 1~8; the light-emitting diode sequentially includes an anode (1), a modified hole transport layer (2), a perovskite thin film layer (3), an electron transport layer (4), an electron injection layer (5) and a cathode (6) from bottom to top.
10. An efficient all-inorganic tin-based near-infrared perovskite light-emitting diode according to claim 9, characterized in that, The anode (1) is made of an ITO substrate; the cathode (6) is made of Al.