Perovskite material, solar cell, preparation method therefor, electrical device and power generation equipment

Abstract

Disclosed in the present application are a perovskite material, a solar cell, a preparation method therefor, an electrical device and power generation equipment. The general formula of the perovskite material is MxFAyA1-x-yBX3, M+ being a N-containing monovalent cation, FA+ being formamidinium, A being at least one of inorganic or organic monovalent cations, B being at least one inorganic divalent cation, and X being at least one monovalent anion. The embodiment of the present application dopes a formamidinium-containing perovskite material with a N-containing monovalent cation so as to improve same, thus improving the stability of corresponding perovskite solar cells.

Description

Perovskite material, solar cell and preparation method, electrical equipment and power generation equipment

[0001] This disclosure claims priority to Chinese patent application No. 2024102697358, filed on March 8, 2024, entitled “PEROVSKITE MATERIALS, SOLAR CELLS AND PREPARATION METHODS, ELECTRICAL EQUIPMENT AND POWER GENERATION EQUIPMENT,” which is hereby incorporated by reference into this disclosure in its entirety. Technical Field

[0002] The present invention relates to the technical field of photovoltaic devices, and in particular to a perovskite material, a solar cell and a preparation method thereof, an electrical device and a power generation device. Background Art

[0003] This section merely provides background information related to the present application and is not necessarily prior art.

[0004] Perovskite solar cells have broad application prospects due to their high conversion efficiency and ease of preparation. However, the perovskite material is prone to crystalline structural instability, which directly affects the device stability and is a major factor affecting the service life of perovskite solar cells. Summary of the Invention

[0005] In view of the technical problems existing in the background technology, the present application provides a perovskite material, a solar cell and a preparation method, an electrical device and a power generation device, aiming to improve the device stability of the solar cell.

[0006] In order to achieve the above-mentioned purpose, the first aspect of the present application provides a perovskite material, the general formula of the perovskite material is M x FA y A 1-x-y BX3,0 <x≤0.1,0.5≤y<1,1-x-y≥0;

[0007] Among them, M + Including monovalent cations containing N elements; FA + A is the formamidinium cation; + including at least one of inorganic or organic monovalent cations, B 2+ comprising at least one inorganic divalent cation, X - Includes at least one monovalent anion.

[0008] In the embodiment of the present application, the perovskite material containing formamidinium cations is doped with monovalent cations containing N element to improve the performance. The monovalent cations containing N element form hydrogen bonds with the formamidinium cations, thereby enhancing the stability of the formamidinium cations in the crystal lattice and stabilizing the crystal structure of the perovskite material, making the perovskite material less prone to X -Ion vacancy defects and other defects can realize the defect passivation of perovskite materials, and due to the X - Ion vacancy defects are both carrier recombination sites and migration channels for X ions. - The passivation of defects such as ion vacancy defects is also beneficial to reducing ion migration channels and reducing the impact of ion migration on the performance of corresponding solar cells, thereby improving the stability of the corresponding perovskite solar cells.

[0009] In some embodiments, A + Including MA + 、Cs + , Rb + , K + DMA + , EA + , GA + One or more of B 2+ Including Pb 2+ 、Sn 2+ 、Ge 2+ 、Cd 2+ 、Sb 2+ 、Zn 2+ 、Mn 2+ , Ca 2+ One or more of X - Including I - Br - 、Cl - 、SCN - HCOO - 、CH3COO - CF3COO - 、CH3SO3 - CF3SO3 - 、CN - One or more of the .

[0010] The embodiment of the present application provides a perovskite material A comprising a formamidinium cation. + 、B 2+ 、X - The specific scheme of ions is conducive to making the crystal structure of the corresponding perovskite material have higher stability.

[0011] In some embodiments, X - Ions include I - , I - In X - The molar ratio of ions is greater than or equal to 0.5.

[0012] In the embodiments of the present application, the anions of the perovskite material containing formamidinium cations are limited to include at least iodide ions. The ionic radius of iodide ions is large, the covalent interaction between the anions of the perovskite material and the metal cations is strong, and the corresponding perovskite material has high stability.

[0013] In some embodiments, A + Including Cs + and MA + One or two of A + In M + , FA + and A + The molar ratio in the sum of the ions is less than or equal to 0.4.

[0014] The embodiments of the present application dope the perovskite material containing the formamidinium cation with cesium cations and / or methylamine cations having smaller ionic radii, effectively reducing the formation energy of the α phase by reducing the tolerance factor, reducing the formation of δ phase impurities during the production process, thereby inhibiting adverse phase transitions during the use of the perovskite material and improving the stability of the perovskite material containing the formamidinium cation. In addition, since the radius of the monovalent cation containing the N element is larger than the radius of the formamidinium cation, and the radius of the cesium cation and / or methylamine cation is smaller than the formamidinium cation, the radii of the monovalent cation containing the N element and the cesium cation and / or methylamine cation are balanced with each other, which is beneficial to reducing the local tensile and compressive strains in the perovskite lattice and improving the stability of the perovskite material containing the formamidinium cation.

[0015] In some embodiments, A + Ions include Cs + , Cs + In M + , FA + and A + The molar ratio in the sum of the ions is less than or equal to 0.4.

[0016] The embodiments of the present application dope the perovskite material containing formamidinium cations with cesium cations having a smaller ionic radius, effectively reducing the formation energy of the α phase by reducing the tolerance factor, reducing the formation of δ phase impurities during the production process, thereby inhibiting adverse phase transitions during the use of the perovskite material and improving the stability of the perovskite material containing formamidinium cations. In addition, because the radius of the monovalent cation containing the nitrogen element is larger than the radius of the formamidinium cation, and the radius of the cesium cation is smaller than the formamidinium cation, the radii of the monovalent cation containing the nitrogen element and the cesium cation are balanced with each other, which is beneficial to reducing the local tensile and compressive strains in the perovskite lattice and improving the stability of the perovskite material containing formamidinium cations.

[0017] In some embodiments, B 2+ Including Pb 2+ and Sn2+ , Pb 2+ In B 2+ The molar ratio in the ions is greater than 0 and less than 1.

[0018] In the embodiment of the present application, Pb is selected as the metal cation. 2+ and Sn 2+ , regulating the band gap of the formed perovskite material so that the formed perovskite material can have a narrower band gap, a higher absorption coefficient and a lower free carrier recombination rate, which is beneficial to improving the photoelectric conversion efficiency of the corresponding perovskite solar cell.

[0019] In some embodiments, the radius of the monovalent cation containing the N element is larger than the radius of the formamidinium cation.

[0020] In the embodiments of the present application, the radius of the monovalent cation containing the N element is larger than the radius of the formamidinium cation. The doping of the monovalent cation containing the N element with a larger radius can balance the radii of other A-site cations, thereby achieving lattice strain regulation and stabilization of the α phase without negatively affecting the band gap.

[0021] In some embodiments, the monovalent cation containing a N element includes one or more of a substituted or unsubstituted N-containing heterocyclic cation and a substituted or unsubstituted guanidinium cation.

[0022] The embodiments of the present application provide monovalent cations containing N elements, which enhance the hydrogen bonding between the monovalent cations containing N elements and the formamidine cations, reduce the migration of the formamidine cations and the outgassing of formamidine, and can effectively improve the stability of the corresponding perovskite solar cell.

[0023] In some embodiments, the substituted or unsubstituted N-containing heterocyclic cation includes one or more of a substituted or unsubstituted pyrrolyl cation, a substituted or unsubstituted pyrrolidinyl cation, a substituted or unsubstituted piperidinyl cation, a substituted or unsubstituted pyridinyl cation, a substituted or unsubstituted pyrazinyl cation, a substituted or unsubstituted piperazinyl cation, and a substituted or unsubstituted 1,2,3,4-tetrahydro-[1,3,5]triazinyl cation.

[0024] The embodiment of the present application provides the above-mentioned substituted or unsubstituted N-containing heterocyclic cation as a monovalent cation containing the N element to dope the perovskite material containing the formamidinium cation, thereby passivating the X inside the perovskite crystal and at the grain boundary. - Vacancy defects reduce carrier recombination sites and ion migration channels, regulate the lattice strain of perovskite materials, stabilize the crystal phase of perovskite materials, and improve the photoelectric conversion efficiency and stability of perovskite solar cells.

[0025] In some embodiments, the monovalent cation containing the N element includes one or more of a substituted N-heterocyclic cation and a substituted guanidinium cation; the substituent groups of the substituted N-heterocyclic cation and the substituted guanidinium cation are independently selected from -D1 and -L1-D1, wherein L1 includes an aliphatic hydrocarbon group having 1 to 5 carbon atoms, and D1 includes one or more of a methyl group, a cyano group, a carboxyl group, a trifluoromethanesulfonyl group, a phenyl group, a pyridyl group, a benzylideneamino group, an amino group, an acetyl group, a formyl group, a halogen group, a phenyl group substituted with one to four halogens, a benzylideneamino group substituted with one to two halogens, and a (trifluoromethyl)phenyl group.

[0026] The embodiment of the present application improves the perovskite material containing formamidinium cations by doping with multifunctional N-containing cations, which can passivate the X-ray diffraction inside the perovskite crystal and at the grain boundary. - Vacancy defects, and they can also play a role of self-passivation, which is further beneficial to reducing defects inside the perovskite crystal and at the grain boundaries. In addition, they can also regulate the seed formation energy and crystal growth rate during the crystallization process, further improving the crystallization quality of the formed perovskite layer, which is beneficial to further improve the photoelectric conversion efficiency of the corresponding perovskite solar cell.

[0027] In some embodiments, the monovalent cation containing the N element includes one or more of a 3-bromopyridinium cation, a 1-cyanoguanidine cation, a 1-(trifluoromethanesulfonyl)guanidine cation, a 1-acetylguanidine cation, a 1,2,3,4-tetrahydro-[1,3,5]triazine cation, a 1-(2,6-dichlorobenzylideneamino)guanidine cation, and a 1-(2-chloroethyl)piperidinium cation.

[0028] The embodiments of the present application achieve doping improvement of perovskite materials containing formamidinium cations by providing specific monovalent cations containing the N element, so as to passivate the defects of the perovskite material, reduce ion migration channels, regulate the lattice strain of the perovskite material, stabilize the crystal phase of the perovskite material, and improve the stability of the corresponding solar cell.

[0029] In a second aspect, an embodiment of the present application provides a solar cell, comprising:

[0030] A light absorbing layer, wherein the material forming the light absorbing layer includes a perovskite material;

[0031] The perovskite material is any perovskite material provided in the first aspect.

[0032] An embodiment of the present application provides a solar cell comprising any of the above-mentioned perovskite materials. Since the defects of the perovskite material are reduced, the ion migration channels are reduced, and the crystal phase is stable, the formed solar cell has good stability.

[0033] In a third aspect, an embodiment of the present application provides a method for preparing a solar cell, comprising:

[0034] A perovskite precursor solution is prepared according to the molar ratio of the components of the perovskite material forming the light absorbing layer; wherein the perovskite material is any perovskite material provided in the first aspect;

[0035] The perovskite precursor solution is formed on a substrate and solidified to obtain a light absorbing layer.

[0036] The embodiments of the present application provide a method for preparing solar cells, using a designed perovskite precursor solution to form a light absorption layer with fewer defects, fewer ion migration channels, and a stable crystal phase, thereby improving the stability of the solar cell.

[0037] In some embodiments, the perovskite precursor solution includes a precursor containing a monovalent cation of the N element, and the precursor containing a monovalent cation of the N element includes a salt of a monovalent cation of the N element.

[0038] The embodiments of the present application provide a salt including a monovalent cation containing a N element as a precursor of the monovalent cation containing a N element, thereby easily achieving doping improvement of the perovskite material containing a formamidinium cation.

[0039] In some embodiments, the anion corresponding to the salt of the monovalent cation containing the N element includes an iodide anion I - , bromide anion Br - 、Chloride anion Cl - , thiocyanate anion SCN - , carboxylate anion HCOO - , acetate anion CH3COO - , trifluoroacetate anion CF3COO - , methanesulfonate anion CH3SO3 - , trifluoromethanesulfonate anion CF3SO3 - , cyanate anion CN - One or more of.

[0040] The embodiments of the present application provide the anions corresponding to the above-mentioned specific salts of monovalent cations containing N elements, so that when the cations of the salts of monovalent cations containing N elements participate in the doping improvement of the perovskite material containing formamidinium cations, their anions participate in the formation of X-site anions of the perovskite material containing formamidinium cations, thereby improving the utilization of the salts of monovalent cations containing N elements, and no anions other than the X-site anions are introduced into the reaction system, thereby reducing the adverse effects on the perovskite material formed by the reaction.

[0041] In some embodiments, the precursor comprising a monovalent cation containing a N element includes one or more of: 3-bromopyridine, 1-cyanoguanidine, 1-(trifluoromethanesulfonyl)guanidine, 1-acetylguanidine, 1,2,3,4-tetrahydro-[1,3,5]triazine, 1-(2,6-dichlorobenzylideneamino)guanidine, 1-(2-chloroethyl)piperidine hydrochloride, bromate, iodate, thiocyanate, formate, acetate, trifluoroacetate, trifluoromethanesulfonate, and cyanate.

[0042] The embodiments of the present application provide some specific precursors including the monovalent cation containing the N element to achieve doping improvement of the perovskite material containing formamidinium cations, so as to passivate the defects of the perovskite material, reduce the ion migration channel, regulate the lattice strain of the perovskite material, stabilize the crystal phase of the perovskite material, and improve the stability of the corresponding perovskite solar cell.

[0043] In a fourth aspect, an embodiment of the present application provides an electrical device, comprising the solar cell provided in the second aspect; or comprising a solar cell prepared by any of the solar cell preparation methods provided in the third aspect.

[0044] In the embodiments of the present application, solar cells are used as the power source for electrical equipment to achieve normal operation of the electrical equipment. Electrical equipment using the solar cells provided by the present application has at least the same advantages as solar cells and can improve the battery performance of the electrical equipment.

[0045] In a fifth aspect, an embodiment of the present application provides a power generation device, comprising the solar cell provided in the second aspect; or comprising a solar cell prepared by any of the solar cell preparation methods provided in the third aspect.

[0046] In the embodiments of the present application, solar cells are used as the energy source of the power generation device to achieve the power output of the power generation device. The power generation device using the solar cells provided by the present application has at least the same advantages as solar cells and can improve the power generation performance of the power generation device. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0048] FIG1 is a schematic structural diagram of a solar cell provided in an embodiment of the present application;

[0049] FIG2 is a schematic structural diagram of an electrical device provided in an embodiment of the present application;

[0050] FIG3 is a schematic structural diagram of a power generation device provided in an embodiment of the present application.

[0051] Explanation of the accompanying drawings: 100 - solar cell, 10 - light absorption layer, 1000 - electrical equipment, 2000 - power generation equipment. DETAILED DESCRIPTION

[0052] The present application will be further described below in conjunction with specific embodiments. It should be understood that these specific embodiments are only used to illustrate the present application and are not used to limit the scope of the present application.

[0053] For the sake of clarity, only some numerical ranges are specifically disclosed herein. However, any lower limit may be combined with any upper limit to form an unspecified range; and any lower limit may be combined with other lower limits to form an unspecified range, and similarly, any upper limit may be combined with any other upper limit to form an unspecified range. In addition, each individually disclosed point or single value may itself serve as a lower limit or upper limit and be combined with any other point or single value, or with other lower limits or upper limits, to form an unspecified range.

[0054] In the description herein, unless otherwise indicated, the term "or" is inclusive. That is, the phrase "A or B" means "A, B, or both A and B." More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0055] In the description of this article, it should be noted that, unless otherwise specified, “above” and “below” include the number itself, and “several” in “one or several” means two or more.

[0056] Unless otherwise specified, the terms used in this application have the commonly understood meanings commonly understood by those skilled in the art. Unless otherwise specified, the numerical values ​​of the various parameters mentioned in this application can be measured using various measurement methods commonly used in the art (for example, they can be tested according to the methods given in the examples of this application).

[0057] FA + The band gap of the perovskite material (formamidinium-based perovskite material) is close to the Shockley-Queisser limit of 1.34 eV, which is suitable as a light absorbing material. + The diamine group, FA + There is a stronger interaction inside the perovskite material, which makes FA + The perovskite-based materials show good thermal stability. +The ionic radius is large, the lattice strain is large, and it is easy to react to temperature, humidity, and light, causing the formamidinium cation FA + Migration and FA + The release of formamidine FA(0) gas formed after deprotonation, in addition, the formamidine cation FA + The rotational disorder is large, and the formation energy of the crystal phase with good photoactivity is high. Even if a crystal phase with good photoactivity is formed, it is easy to transform into a crystal phase with poor photoactivity. The above reasons are likely to lead to FA + The stability of the perovskite-based materials decreases.

[0058] To solve the above technical problems, the embodiments of the present application provide a perovskite material, a solar cell and a preparation method, an electrical device and a power generation device.

[0059] The technical solutions described in the embodiments of this application are applicable to perovskite materials, solar cells and preparation methods, electrical equipment, and power generation equipment. The solar cells disclosed in this application can be used in tandem solar cells containing perovskites, such as perovskite-perovskite tandem solar cells, silicon-perovskite tandem solar cells, and perovskite-heterojunction tandem solar cells, without limitation in this application.

[0060] The present application is described in detail below with reference to the accompanying drawings and embodiments.

[0061] In order to achieve the above-mentioned purpose, the first aspect of the present application provides a perovskite material, the general formula of the perovskite material is M x FA y A 1-x-y BX3,0 <x≤0.1,0.5≤y<1,1-x-y≥0。

[0062] Among them, M + Including monovalent cations containing N elements; FA + A is the formamidinium cation; + including at least one of inorganic or organic monovalent cations, B 2+ comprising at least one inorganic divalent cation, X - Includes at least one monovalent anion.

[0063] Among them, the perovskite material refers to a material with the same crystal structure as CaTiO3, which presents a cubic crystal phase in a stable state and serves as the main forming material of the perovskite layer.

[0064] The cation of the perovskite provided in the embodiment of the present application is a monovalent cation containing the N element, a formamidinium cation FA + Doping, monovalent cations containing N elements and formamidinium cations FA + hydrogen bonds are formed between them, reducing the FA +The lattice strain of the perovskite material enhances the FA + Migration and FA + The energy barrier for the release of formamidine FA(0) gas formed after deprotonation, thereby reducing the energy barrier for the formamidine cation FA + Migration and FA + The release of formamidinium FA(0) gas formed after deprotonation. In addition, the monovalent cation containing nitrogen element reacts with the formamidinium cation FA + The hydrogen bond is formed between the two, which reduces the FA + The rotational disorder reduces the formation energy of the crystal phase with good photoactivity, and it is not easy to transform from the crystal phase with good photoactivity to the crystal phase with poor photoactivity. The above reasons are all conducive to improving FA + The stability of perovskite-based materials.

[0065] A + Comprising at least one of inorganic or organic monovalent cations means A + It may include only inorganic monovalent cations, only organic monovalent cations, or both inorganic monovalent cations and organic monovalent cations, depending on specific needs.

[0066] B 2+ Comprising at least one inorganic divalent cation means B 2+ It may include only one inorganic divalent cation or multiple inorganic divalent cations, depending on the specific needs.

[0067] X - Comprising at least one monovalent anion means that X - It may include only one monovalent anion or multiple monovalent anions, depending on the specific needs.

[0068] In some embodiments, the value of x can be 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, etc., or a range consisting of any two of the above values, for example, it can be 0.01-0.04, 0.02-0.05, 0.03-0.06, 0.04-0.07, 0.05-0.08, 0.06-0.09, 0.07-0.1, etc.

[0069] In some embodiments, the value of y can be 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 0.99, etc., or a range consisting of any two of the above values, for example, it can be 0.5-0.7, 0.55-0.75, 0.6-0.8, 0.65-0.85, 0.7-0.9, 0.75-0.95, 0.8-0.99, etc.

[0070] In the embodiment of the present application, the perovskite material containing formamidinium cations is doped with monovalent cations containing N element to improve the performance. The monovalent cations containing N element form hydrogen bonds with the formamidinium cations, thereby enhancing the stability of the formamidinium cations in the crystal lattice and stabilizing the crystal structure of the perovskite material, making the perovskite material less prone to X - Ion vacancy defects and other defects can realize the defect passivation of perovskite materials, and due to the X - Ion vacancy defects are both carrier recombination sites and migration channels for X ions. - The passivation of defects such as ion vacancy defects is also beneficial to reducing ion migration channels and reducing the impact of ion migration on the performance of corresponding solar cells, thereby improving the stability of the corresponding perovskite solar cells.

[0071] In some embodiments, A + Including methylammonium cation MA + , cesium cation Cs + 、Rubidium cation Rb + 、Potassium cation K + , dimethylamine cation DMA + , ethylenediamine cation EA + , guanidine cation GA + One or more of; and / or B 2+ Including lead cation Pb 2+ , tin cation Sn 2+ 、Ge cation 2+ , cadmium cation Cd 2+ 、Antimony cation Sb 2+ 、Zinc cation Zn 2+ 、Manganese cation Mn 2+ Calcium cation Ca 2+ One or more of; and / or X - Including iodide anion I - , bromide anion Br - 、Chloride anion Cl - , thiocyanate anion SCN - , carboxylate anion HCOO - , acetate anion CH3COO - , trifluoroacetate anion CF3COO - , methanesulfonate anion CH3SO3 - , trifluoromethanesulfonate anion CF3SO3 - , cyanate anion CN - One or more of the .

[0072] Among them, the monovalent cation A+ For paraformamidinium cation FA + Doping, and with monovalent cations M containing N elements + Working together, further increase the FA + The hydrogen bond formed between the formamidine cation FA + Migration and FA + The release of formamidine FA(0) gas formed after deprotonation also reduces the formamidine cation FA + The rotational disorder reduces the formation energy of the crystal phase with good photoactivity, and it is not easy to transform from the crystal phase with good photoactivity to the crystal phase with poor photoactivity. The above reasons are all conducive to improving FA + The stability of perovskite-based materials.

[0073] The embodiment of the present application provides a perovskite material A comprising a formamidinium cation. + 、B 2+ 、X - The specific scheme of ions is conducive to making the crystal structure of the corresponding perovskite material have higher stability.

[0074] In some embodiments, X - Ions include I - , I - In X - The molar ratio of ions is greater than or equal to 0.5.

[0075] Among them, in the general formula of perovskite material M x FA y A 1-x-y In BX3, the monovalent cation M containing N element + , formamidinium cation FA + , monovalent cation A + 、Divalent cation B 2+ 、Anion X - The molar ratio is x:y:1-xy:1:3. Iodide anion I - In X - The molar ratio of ions is greater than or equal to 0.5, which means that the iodide anion I - The number of moles of X - 50% or more of the total molar number of ions, i.e., iodide anion I - The subscript in the general formula of the perovskite material is greater than or equal to 1.5 and less than or equal to 3.

[0076] In some embodiments, the iodide anion I - In X - The molar ratio of X in the perovskite material can be 100%. - Ions are all iodide anions I- , the corresponding general formula of perovskite material is M x FA y A 1-x-y BI3, due to the iodide anion I - The ionic radius of the iodide anion I - With divalent cation B 2+ The covalent interaction is stronger, and the corresponding perovskite material has higher stability.

[0077] In some embodiments, the iodide anion I - In X - The molar ratio of iodide anion is greater than or equal to 0.5 and less than 1, that is, the iodide anion I - The subscript in the general formula of perovskite material is greater than or equal to 1.5 and less than 3, that is, X - Ions are formed by mixing at least two anions. Due to the different ionic radii of the two anions, the divalent cation B 2+ The surrounding charges are offset, and the chemical bond energy between the BX ions inside the crystal structure increases, causing the octahedron to shrink and distort, thereby further reducing the lattice constant and improving the stability of the perovskite material.

[0078] In some embodiments, I - In X - The molar ratio in the ions can be 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, etc., or a range consisting of any two of the above values, for example, it can be 0.5-0.65, 0.55-0.7, 0.6-0.75, 0.65-0.8, 0.7-0.85, 0.75-0.9, 0.8-0.95, 0.85-1, etc.

[0079] In the embodiments of the present application, the anions of the perovskite material containing formamidinium cations are limited to include at least iodide ions. The ionic radius of iodide ions is large, the covalent interaction between the anions of the perovskite material and the metal cations is strong, and the corresponding perovskite material has high stability.

[0080] In some embodiments, A + Including Cs + and MA + One or two of A + In M + , FA + and A + The molar ratio of the total ions is less than or equal to 0.4. + In M + , FA + and A + The molar ratio of the total ions is less than or equal to 0.4, which means Cs+ In M + , FA + and A + The molar ratio of the sum of ions is less than or equal to 0.4, or refers to MA + In M + , FA + and A + The molar ratio of the total ion is less than or equal to 0.4, or refers to Cs + and MA + The sum of the molar numbers of M + , FA + and A + The molar ratio of the total number of moles of ions is less than or equal to 0.4. + Including Cs + and MA + In the case of + and MA + The molar ratio of Cs is not limited, as long as + and MA + The sum of the molar numbers of M + , FA + and A + The molar ratio of the total number of moles of ions is less than or equal to 0.4. In some embodiments, + Including Cs + and MA + In the case of + and MA + The molar ratio is 1:2.9.

[0081] The embodiments of the present application dope the perovskite material containing the formamidinium cation with cesium cations and / or methylamine cations having smaller ionic radii, effectively reducing the formation energy of the α phase by reducing the tolerance factor, reducing the formation of δ phase impurities during the production process, thereby inhibiting adverse phase transitions during the use of the perovskite material and improving the stability of the perovskite material containing the formamidinium cation. In addition, since the radius of the monovalent cation containing the nitrogen element is larger than the radius of the formamidinium cation, and the radius of the cesium cation and / or methylamine cation is smaller than the formamidinium cation, the radii of the monovalent cation containing the nitrogen element and the cesium cation and / or methylamine cation are balanced with each other, which is beneficial to reducing the local tensile and compressive strains in the perovskite lattice and improving the stability of the perovskite material containing the formamidinium cation.

[0082] In some embodiments, A + Ions include Cs + , Cs + In M + , FA + and A + The molar ratio in the sum of the ions is less than or equal to 0.4.

[0083] Among them, A + The ions include cesium cation Cs + , cesium cation Cs + has a smaller ionic radius than the formamidinium cation FA + . The doping of cesium cation Cs + is beneficial to release the large internal microscopic strain in the FA + -based perovskite material, enhance the hydrogen bond strength between the formamidinium cation FA + and the [BX6] 4- octahedron, reduce the rotation of the [BX6] 4- octahedron and hinder the migration of internal formamidinium cation FA, thereby improving the stability of the FA + -based perovskite material.

[0084] In some embodiments, the molar ratio of Cs + in the sum of M + , FA + and A + ions can be 0.01, 0.02, 0.05, 0.08, 0.1, 0.12, 0.15, 0.18, 0.2, 0.22, 0.25, 0.28, 0.3, 0.32, 0.35, 0.38, 0.4, etc., or the range composed of any two of the above values. For example, it can be 0 to 0.05, 0.025 to 0.1, 0.08 to 0.15, 0.1 to 0.2, 0.12 to 0.25, 0.15 to 0.28, 0.18 to 0.3, 0.2 to 0.35, 0.25 to 0.4, etc.

[0085] In some embodiments, the general formula of the perovskite material provided by the embodiments of the present application is M x FA y Cs 1-x-y PbI3, 0 < x ≤ 0.1, 0.5 ≤ y < 1, 1 - x - y > 0, which is equivalent to doping a monovalent cation containing N element and cesium cation Cs + on the basis of the FAPbI3 phase. Among them, FAPbI3 has a wide light absorption range, is prone to exciton dissociation at room temperature, generates a large number of electron-hole pairs, is suitable as a light absorption layer material, and has good application prospects. However, FAPbI3 undergoes a spontaneous phase change at room temperature, changing from the black α-phase perovskite with good optoelectronic activity to the yellow δ-phase non-perovskite with poor optoelectronic activity. This phase change process will hinder the further commercial application of FAPbI3 perovskite solar cells.

[0086] The present application uses a monovalent cation containing N element and cesium cation Cs +The doping of N reduces the formation energy of α-phase FAPbI3, inhibits the transformation of α-phase FAPbI3 to δ-phase FAPbI3, and improves the stability of the corresponding perovskite material. + There is a certain difference in the ionic radius of the two, and the two balance each other, which is beneficial to reduce the local tensile and compressive strains in the perovskite lattice and further improve the stability of solar cells containing the corresponding perovskite materials.

[0087] The embodiments of the present application dope the perovskite material containing formamidinium cations with cesium cations having a smaller ionic radius, effectively reducing the formation energy of the α phase by reducing the tolerance factor, reducing the formation of δ phase impurities during the production process, thereby inhibiting adverse phase transitions during the use of the perovskite material and improving the stability of the perovskite material containing formamidinium cations. In addition, because the radius of the monovalent cation containing the nitrogen element is larger than the radius of the formamidinium cation, and the radius of the cesium cation is smaller than the formamidinium cation, the radii of the monovalent cation containing the nitrogen element and the cesium cation are balanced with each other, which is beneficial to reducing the local tensile and compressive strains in the perovskite lattice and improving the stability of the perovskite material containing formamidinium cations.

[0088] In some embodiments, B 2+ Including Pb 2+ and Sn 2+ , Pb 2+ In B 2+ The molar ratio in the ions is greater than 0 and less than 1.

[0089] Among them, divalent cation B 2+ At least two divalent cations, namely at least lead cation Pb 2+ and tin cation Sn 2+ , which is used to regulate the band gap of the formed perovskite material so that the formed perovskite material can have a narrower band gap, a higher absorption coefficient and a lower free carrier recombination rate.

[0090] In some embodiments, Pb 2+ In B 2+ The molar ratio in the ions can be 0.01, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 0.99, etc., or a range consisting of any two of the above values, for example, 0.01-0.3, 0.1-0.45, 0.2-0.6, 0.3-0.7, 0.4-0.8, 0.5-0.9, 0.6-0.99, etc.

[0091] In the embodiment of the present application, Pb is selected as the metal cation.2+ and Sn 2+ , regulating the band gap of the formed perovskite material so that the formed perovskite material can have a narrower band gap, a higher absorption coefficient and a lower free carrier recombination rate, which is beneficial to improving the photoelectric conversion efficiency of the corresponding perovskite solar cell.

[0092] In some embodiments, the radius of the monovalent cation containing the N element is larger than the radius of the formamidinium cation.

[0093] In the embodiments of the present application, the radius of the monovalent cation containing the N element is larger than the radius of the formamidinium cation. The doping of the monovalent cation containing the N element with a larger radius can balance the radii of other A-site cations, thereby achieving lattice strain regulation and stabilization of the α phase without negatively affecting the band gap.

[0094] In some embodiments, the monovalent cation containing a N element includes one or more of a substituted or unsubstituted N-containing heterocyclic cation and a substituted or unsubstituted guanidinium cation.

[0095] Among them, the N-heterocyclic cation refers to an organic cation containing a heterocyclic structure, and the elements constituting the heterocyclic ring contain at least one nitrogen element N in addition to carbon. The chemical formula of the guanidine cation is -NH-C(NH2)=NH2 + The substituted or unsubstituted N-containing heterocyclic cation and / or guanidine cation has a larger ionic radius, which is beneficial to enhance the stability of the formamidinium cation in the crystal lattice, thereby stabilizing the crystal phase structure of the perovskite material, achieving defect passivation of the perovskite material, and reducing the ion migration channel, thereby improving the stability of the corresponding perovskite solar cell. In some embodiments, when the monovalent cation containing the N element includes a substituted or unsubstituted guanidine cation, A + GA not included + In some embodiments, in A + Including GA + In the case of N, the monovalent cation containing the N element does not include substituted or unsubstituted guanidinium cations.

[0096] The embodiments of the present application provide monovalent cations containing N elements, which enhance the hydrogen bonding between the monovalent cations containing N elements and the formamidine cations, reduce the migration of the formamidine cations and the outgassing of formamidine, and can effectively improve the stability of the corresponding perovskite solar cell.

[0097] In some embodiments, the substituted or unsubstituted N-containing heterocyclic cation includes one or more of a substituted or unsubstituted pyrrolyl cation, a substituted or unsubstituted pyrrolidinyl cation, a substituted or unsubstituted piperidinyl cation, a substituted or unsubstituted pyridinyl cation, a substituted or unsubstituted pyrazinyl cation, a substituted or unsubstituted piperazinyl cation, and a substituted or unsubstituted 1,2,3,4-tetrahydro-[1,3,5]triazinyl cation.

[0098] Among them, the structural formula of the pyrrolyl cation is The structural formula of the pyrrolidinyl cation is The structural formula of the piperidinyl cation is The structural formula of the pyridyl cation is The structural formula of the pyrazinyl cation is The structural formula of the piperazinyl cation is The structural formula of 1,2,3,4-tetrahydro-[1,3,5]triazine cation is Substitution refers to the replacement of certain atoms or atomic groups in organic molecules by other atoms or atomic groups.

[0099] The embodiments of the present application provide the above-mentioned substituted or unsubstituted N-containing heterocyclic cations as monovalent cations containing the N element to improve the doping of perovskite materials containing formamidinium cations, passivate the X vacancy defects inside the perovskite crystals and at the grain boundaries, reduce carrier recombination sites and ion migration channels, regulate the lattice strain of the perovskite material, stabilize the crystal phase of the perovskite material, and improve the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0100] In some embodiments, the monovalent cation containing the N element includes one or more of a substituted N-heterocyclic cation and a substituted guanidinium cation; the substituent groups of the substituted N-heterocyclic cation and the substituted guanidinium cation are independently selected from -D1 and -L1-D1, wherein L1 includes an aliphatic hydrocarbon group having 1 to 5 carbon atoms, and D1 includes one or more of a methyl group, a cyano group, a carboxyl group, a trifluoromethanesulfonyl group, a phenyl group, a pyridyl group, a benzylideneamino group, an amino group, an acetyl group, a formyl group, a halogen group, a phenyl group substituted with one to four halogens, a benzylideneamino group substituted with one to two halogens, and a (trifluoromethyl)phenyl group.

[0101] Among them, aliphatic hydrocarbon groups refer to the groups left after removing some hydrogen atoms from hydrocarbons with the basic properties of aliphatic compounds. The chemical formula of methyl is -CH3, the chemical formula of cyano is -CN, the chemical formula of carboxyl is -COOH, and the structural formula of trifluoromethanesulfonyl is The structural formula of phenyl is The structural formula of pyridyl is The structural formula of benzylideneamino is The chemical formula of amino group is -NH2, and the structural formula of acetyl group is The chemical formula of formyl is -C=O, halogen includes -F (fluoro), -Cl (chloro), -Br (bromo) or -I (iodo), and the chemical formula of (trifluoromethyl)phenyl is

[0102] The embodiments of the present application improve the doping of perovskite materials containing formamidinium cations by using multi-functional N-containing cations, which can passivate X vacancy defects inside the perovskite crystals and at the grain boundaries, and can also play a self-passivating role, which is further beneficial to reducing defects inside the perovskite crystals and at the grain boundaries. In addition, it can also regulate the seed formation energy and crystal growth rate during the crystallization process, further improve the crystallization quality of the formed perovskite layer, and help further improve the photoelectric conversion efficiency of the corresponding perovskite solar cell.

[0103] In some embodiments, the monovalent cation containing the N element includes one or more of a 3-bromopyridinium cation, a 1-cyanoguanidine cation, a 1-(trifluoromethanesulfonyl)guanidine cation, a 1-acetylguanidine cation, a 1,2,3,4-tetrahydro-[1,3,5]triazine cation, a 1-(2,6-dichlorobenzylideneamino)guanidine cation, and a 1-(2-chloroethyl)piperidinium cation.

[0104] Among them, the structural formula of 3-bromopyridinium cation is The structural formula of 1-cyanoguanidine cation is The structural formula of 1-(trifluoromethanesulfonyl)guanidine cation is The structural formula of 1-acetylguanidine cation is The structural formula of 1,2,3,4-tetrahydro-[1,3,5]triazine cation is The structural formula of 1-(2,6-dichlorobenzylideneamino)guanidine cation is The structural formula of 1-(2-chloroethyl)piperidinium cation is

[0105] The embodiments of the present application provide specific monovalent cations containing the N element to achieve doping improvement of the perovskite material containing formamidinium cations, thereby passivating the defects of the perovskite material, reducing ion migration channels, regulating the lattice strain of the perovskite material, stabilizing the crystal phase of the perovskite material, and improving the stability of the corresponding solar cell 100.

[0106] Please refer to FIG1 , which is a schematic structural diagram of a solar cell provided in an embodiment of the present application.

[0107] In a second aspect, referring to FIG1 , an embodiment of the present application provides a solar cell 100. The solar cell 100 includes a light absorbing layer 10. The material forming the light absorbing layer 10 includes a perovskite material. The perovskite material is any of the perovskite materials provided in the first aspect.

[0108] Solar cell 100 is a device that converts light energy into electrical energy through the photovoltaic effect. Light absorption layer 10 is the core component of solar cell 100, responsible for absorbing photon energy from sunlight, generating electron-hole pairs. Under the action of a built-in electric field, these electron-hole pairs are separated into free electrons and holes. The holes and electrons are collected by two different electrodes, which are then connected to form a circuit to generate photocurrent.

[0109] In addition to the light absorbing layer 10, the solar cell 100 may further include other film structures, such as a first electrode layer and a second electrode layer, wherein the light absorbing layer 10 is located between the first electrode layer and the second electrode layer. The first electrode layer is used to collect one of the electrons or holes generated by the light absorbing layer, and the second electrode layer is used to collect the other of the electrons or holes generated by the light absorbing layer.

[0110] In some embodiments, at least one of the first electrode layer and the second electrode layer is a transparent electrode for light incidence. In one example, the solar cell 100 further includes a substrate structure for supporting the functional film layers of the solar cell 100. The first electrode layer is disposed on the substrate structure; further, both the first electrode layer and the substrate structure are made of transparent materials. It is understood that in other examples, the second electrode layer may be disposed on the substrate structure, and both the second electrode layer and the substrate structure may be made of transparent materials.

[0111] In some embodiments, the transparent electrode may be a transparent conductive metal oxide electrode. Without limitation, the material of the transparent electrode may include, but is not limited to, one or more of the following materials: FTO (fluorine-doped tin oxide), ITO (tin-doped indium oxide), AZO (aluminum-doped zinc oxide), BZO (boron-doped zinc oxide), IZO (indium zinc oxide), IWO (tungsten-doped indium oxide), lanthanide metal-doped indium oxide, antimony-doped tin oxide, etc. It is understandable that the substrate structure can use glass as a substrate, and a transparent flexible substrate structure can also be used. Specifically, the material of the transparent flexible substrate structure can be, for example, an organic polymer material, which can be mixed by one or more of the following materials in different proportions: polyvinyl alcohol (PVA), polyester (PET), polyimide (PI), polyethylene naphthalate (PEN), polydimethylsiloxane (PDMS).

[0112] In some embodiments, in addition to the material of the other electrode layer serving as the transparent electrode, the material further comprises a conductive material. Further, the conductive material may be an organic conductive material, an inorganic conductive material, or a combination thereof. Non-limiting examples of inorganic conductive materials include metal conductive materials. Further, the metal conductive material may include any one of gold (Au), silver (Ag), copper (Cu), aluminum (Al), nickel (Ni), chromium (Cr), bismuth (Bi), platinum (Pt), magnesium (Mg), etc., or any suitable mixture of the foregoing elements. The conductive material may include a conductive oxide. Further, the conductive material may be a conductive oxide. Non-limiting examples of conductive oxides may include one or more of FTO, ITO, IWO, AZO, etc.

[0113] In some embodiments, the first electrode layer is a transparent electrode, which is an electrode for first receiving incident light.

[0114] In some embodiments, the solar cell 100 may further include one or both of an electron transport layer and a hole transport layer, wherein the electron transport layer and the hole transport layer are respectively located on both sides of the light absorption layer 10, for transporting and extracting electrons and holes, and providing the photoelectric conversion efficiency of the solar cell 100. Furthermore, in the case where the solar cell 100 includes a first electrode layer and a second electrode layer, the electron transport layer and the hole transport layer may be optionally arranged between the first electrode layer and the second electrode layer. In some embodiments, the solar cell 100 includes a substrate structure, a first electrode layer, a hole transport layer, a light absorption layer 10, an electron transport layer, and a second electrode layer stacked in sequence, and the first electrode layer is a transparent electrode; in other embodiments, the solar cell 100 includes a substrate structure, a first electrode layer, an electron transport layer, a light absorption layer 10, a hole transport layer, and a second electrode layer stacked in sequence, and the first electrode layer is a transparent electrode.

[0115] The present application does not specifically limit the hole transport material used in the hole transport layer, and the electron transport material commonly used in the art can be used. Without limitation, the hole transport material can include but is not limited to one or more of the following hole transport materials and their derivatives: 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD), methoxytriphenylamine-fluoroformamidine, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3,4-ethylenedioxythiophene): polystyrene sulfonic acid, poly-3-hexylthiophene, triptycene The core of the present invention is triphenylamine, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-(4-phenylamino)carbazole-spirobifluorene, polythiophene, phosphoric acid-based monomers, carbazole-based monomers, sulfonic acid-based monomers, triphenylamine-based monomers, aromatic monomers, metal oxides (which can be recorded as first metal oxides), cuprous iodide and cuprous thiocyanate. The metal element in the first metal oxide can include one or more of Ni, Mo, W and Cu, for example, nickel oxide (NiO x ), WO3.

[0116] The present application does not specifically limit the electron transport material used in the electron transport layer, and the electron transport materials commonly used in the art can be used. For example, the electron transport material includes one or more of fullerene and its derivatives, imide compounds, metal oxides, metal sulfides, metal fluorides, cyano-containing polyphenylene vinylene, boron-containing polymers, bathocuproin, red phenanthroline, hydroxyquinoline aluminum, oxadiazole compounds, and quinone compounds. Exemplarily, fullerene and its derivatives include one or more of fullerene C60, fullerene C70, PCBM ([6,6]-phenyl-C61-butyric acid methyl ester), [6,6]-phenyl C71 butyric acid methyl ester (PC71BM); imide compounds include one or more of perylene imide materials, naphthalimide materials, phthalimide, succinimide, N-bromosuccinimide, glutarimide or maleimide; the metal element in the metal oxide can be Including one or more of Mg, Ni, Cd, Zn, In, Pb, Mo, W, Sb, Bi, Cu, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga and Cr, such as one or more of tin oxide (SnO2), zinc oxide (ZnO), titanium oxide; metal sulfides such as indium sulfide or zinc sulfide; metal fluorides such as one or more of lithium fluoride (LiF), sodium fluoride, magnesium fluoride (MgF2), calcium fluoride (CaF2).

[0117] The embodiments of the present application provide a solar cell 100 comprising any of the above-mentioned perovskite materials. Since the defects of the perovskite material are reduced, the ion migration channels are reduced, and the crystal phase is stable, the formed solar cell 100 has good stability.

[0118] In a third aspect, an embodiment of the present application provides a method for preparing a solar cell 100, comprising:

[0119] (1) A perovskite precursor solution is prepared according to the molar ratio of the components of the perovskite material forming the light absorbing layer 10; wherein the perovskite material is any perovskite material provided in the first aspect.

[0120] (2) A perovskite precursor solution is formed on a substrate and cured to obtain a light absorbing layer 10 .

[0121] Among them, curing treatment refers to the process of converting a liquid substance into a solid substance. In some embodiments, curing treatment refers to the process of performing heat treatment under certain temperature conditions. In some embodiments, curing treatment includes annealing treatment. Annealing treatment in the process of forming the light absorbing layer 10 from the perovskite precursor solution is a common method. The process parameters such as the temperature and duration of the annealing treatment all adopt the more common numerical range in this field, as long as the curing of the light absorbing layer 10 can be achieved. This application does not impose any restrictions. In some embodiments, the curing treatment is annealing treatment, the temperature range of the annealing treatment is 100°C to 150°C, and the annealing time range is 10min to 40min.

[0122] The embodiment of the present application provides a method for preparing a solar cell 100 , and adopts a designed perovskite precursor solution to form a light absorption layer 10 with fewer defects, fewer ion migration channels, and a stable crystal phase, thereby improving the stability of the solar cell 100 .

[0123] In some embodiments, the perovskite precursor solution includes a precursor containing a monovalent cation of the N element, and the precursor containing a monovalent cation of the N element includes a salt of a monovalent cation of the N element.

[0124] The embodiments of the present application provide a salt including a monovalent cation containing a N element as a precursor of the monovalent cation containing a N element, thereby easily achieving doping improvement of the perovskite material containing a formamidinium cation.

[0125] In some embodiments, the anion corresponding to the salt of the monovalent cation containing the N element includes an iodide anion I - , bromide anion Br - 、Chloride anion Cl - , thiocyanate anion SCN - , carboxylate anion HCOO - , acetate anion CH3COO - , trifluoroacetate anion CF3COO - , methanesulfonate anion CH3SO3 -, trifluoromethanesulfonate anion CF3SO3 - , cyanate anion CN - One or more of.

[0126] The embodiments of the present application provide the anions corresponding to the above-mentioned specific salts of monovalent cations containing N elements, so that when the cations of the salts of monovalent cations containing N elements participate in the doping improvement of the perovskite material containing formamidinium cations, their anions participate in the formation of X-site anions of the perovskite material containing formamidinium cations, thereby improving the utilization of the salts of monovalent cations containing N elements, and no anions other than the X-site anions are introduced into the reaction system, thereby reducing the adverse effects on the perovskite material formed by the reaction.

[0127] In some embodiments, the precursor comprising a monovalent cation containing a N element includes one or more of: 3-bromopyridine, 1-cyanoguanidine, 1-(trifluoromethanesulfonyl)guanidine, 1-acetylguanidine, 1,2,3,4-tetrahydro-[1,3,5]triazine, 1-(2,6-dichlorobenzylideneamino)guanidine, 1-(2-chloroethyl)piperidine hydrochloride, bromate, iodate, thiocyanate, formate, acetate, trifluoroacetate, trifluoromethanesulfonate, and cyanate.

[0128] Among them, the structural formula of 3-bromopyridine is The structural formula of 1-cyanoguanidine is The structural formula of 1-(trifluoromethanesulfonyl)guanidine is The structural formula of 1-acetylguanidine is The structural formula of 1,2,3,4-tetrahydro-[1,3,5]triazine is The hydrochloride of 1-(2,6-dichlorobenzylideneamino)guanidine is The structural formula of 1-(2-chloroethyl)piperidine is

[0129] The embodiments of the present application provide some specific precursors including the monovalent cation containing the N element to achieve doping improvement of the perovskite material containing formamidinium cations, so as to passivate the defects of the perovskite material, reduce the ion migration channel, regulate the lattice strain of the perovskite material, stabilize the crystal phase of the perovskite material, and improve the stability of the corresponding solar cell 100.

[0130] Please refer to FIG2 , which is a schematic structural diagram of an electrical device provided in an embodiment of the present application.

[0131] In the fourth aspect, referring to FIG2 , an embodiment of the present application provides an electrical device 1000 , comprising the solar cell 100 provided in the second aspect; or comprising a solar cell 100 prepared by any method for preparing the solar cell 100 provided in the third aspect.

[0132] In the embodiments of the present application, a solar cell 100 serves as a power source for an electrical device 1000, enabling normal operation of the electrical device 1000. Electrical device 1000 employing the solar cell 100 provided herein has at least the same advantages as the solar cell 100, and can improve battery performance of the electrical device 1000. For example, the electrical device 1000 may include a lighting device, a display device, or a new energy vehicle.

[0133] Please refer to FIG3 , which is a schematic structural diagram of a power generation device provided in an embodiment of the present application.

[0134] In the fifth aspect, referring to FIG3 , an embodiment of the present application provides a power generation device 2000 , comprising the solar cell 100 provided in the second aspect; or comprising a solar cell 100 prepared by any of the methods for preparing the solar cell 100 provided in the third aspect.

[0135] In the embodiments of the present application, a solar cell 100 serves as the energy source for a power generation device 2000, enabling the power generation device 2000 to output electrical energy. Power generation device 2000 utilizes the solar cell 100 provided in the present application and has at least the same advantages as solar cell 100, thereby improving the power generation performance of power generation device 2000. For example, power generation device 2000 can be used in fields such as building power generation, wearable device power generation, smartphone power generation, and vehicle battery power generation.

[0136] In order to make the technical problems, technical solutions and beneficial effects solved by the embodiments of the present application clearer, the following will be further described in detail with reference to the embodiments and drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present application and its applications. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0137] The features and performance of the present application are further described in detail below with reference to the embodiments.

[0138] Example 1

[0139] Preparation of solar cell 100

[0140] (1) Take a 2.0 cm*2.0 cm fluorine-doped tin dioxide conductive glass and remove 0.35 cm of fluorine-doped tin dioxide at each end by laser etching to expose the glass substrate.

[0141] (2) Ultrasonic cleaning of the etched fluorine-doped tin dioxide conductive glass was performed several times with water, acetone, and isopropyl alcohol in sequence; the solvent on the surface of the fluorine-doped tin dioxide conductive glass was blown dry with a nitrogen gun, and the glass was placed in a UV ozone machine for UV ozone treatment.

[0142] (3) A nano-scale nickel oxide precursor solution (solvent: water) with a concentration of 10 mg / mL was spin-coated on the fluorine-doped tin dioxide conductive glass after UV ozone treatment at a rate of 4000 rpm, annealed on a hot plate at 150°C for 30 min, and cooled to room temperature to form a hole transport layer with a thickness of 30 nm.

[0143] (4) Weigh 1.6 mmol of lead iodide (PbI2), 1.504 mmol of iodomethane (FAI), 0.08 mmol of cesium iodide (CsI) and 0.016 mmol of dopant 3-bromopyridine hydrochloride. The above materials were dissolved in 1 mL of a 4:1 volume ratio of DMF and DMSO and stirred for 2 hours. The solution was then filtered through a 0.22 μm organic filter membrane to obtain a perovskite precursor solution. This solution was spin-coated onto the resulting hole transport layer at 5000 rpm for 30 seconds. During the final 5 seconds, 150 μL of anisole was dropwise added to the center of the substrate. The solution was then annealed on a 100°C hot plate for 40 minutes and cooled to room temperature to obtain a 500 nm thick light absorption layer 10.

[0144] (5) C60 with a thickness of 25 nm was evaporated on the light absorption layer 10 using an evaporation machine to form an electron transport layer, and then tin dioxide with a thickness of 20 nm was evaporated on the surface of the electron transport layer; finally, Cu with a thickness of 120 nm was evaporated on the surface of the tin dioxide as a second electrode layer, and a battery device was obtained, which was marked as battery 1.

[0145] Examples 2 to 4 are similar to Example 1, except that the molar amounts of iodoformamidine and the dopant added in step (4) are different. The molar amount of iodoformamidine added in step (4) of Example 2 is 1.512 mmol, and the molar amount of the dopant is 0.008 mmol. The molar amount of iodoformamidine added in step (4) of Example 3 is 1.488 mmol, and the molar amount of the dopant is 0.032 mmol. The molar amount of iodoformamidine added in step (4) of Example 4 is 1.472 mmol, and the molar amount of the dopant is 0.048 mmol.

[0146] Examples 5 to 10 are similar to Example 1, except that different dopants are used in step (4). In particular, the dopant used in Example 5 is 1-cyanoguanidine hydrochloride, the dopant used in Example 6 is 1-(trifluoromethanesulfonyl)guanidine hydrochloride, the dopant used in Example 7 is 1-acetylguanidine hydrochloride, the dopant used in Example 8 is 1,2,3,4-tetrahydro-[1,3,5]triazine hydrochloride, the dopant used in Example 9 is 1-(2,6-dichlorobenzylideneamino)guanidine hydrochloride, and the dopant used in Example 10 is 1-(2-chloroethyl)piperidine hydrochloride.

[0147] Comparative Example 1 is similar to Example 1, except that no dopant is added in step (4), and the drugs dissolved in 1 mL of a mixed solvent of DMF and DMSO in a volume ratio of 4:1 are 1.52 mmol of FAI, 0.08 mmol of CsI, and 1.6 mmol of PbI2.

[0148] Comparative Example 2 is similar to Example 1, except that the dopant added in step (4) is dimethylamine chloride.

[0149] Example 11 is similar to Example 1, except that in step (4), the drugs dissolved in 1 mL of a mixed solvent of DMF and DMSO in a volume ratio of 4:1 are 0.016 mmol of dopant 3-bromopyridine hydrochloride, 1.264 mmol of FAI, 0.32 mmol of CsI, 0.9568 mmol of PbBr2, and 0.6432 mmol of PbI2.

[0150] Comparative Example 3 is similar to Example 11, except that no dopant is added in step (4), and the drugs dissolved in 1 mL of a mixed solvent of DMF and DMSO in a volume ratio of 4:1 are 1.28 mmol of FAI, 0.32 mmol of CsI, 0.96 mmol of PbBr2, and 0.64 mmol of PbI2.

[0151] Example 12 is similar to Example 1, except that in step (4), the drugs dissolved in 1 mL of a mixed solvent of DMF and DMSO in a volume ratio of 4:1 are 0.016 mmol of dopant 3-bromopyridine hydrochloride, 0.16 mmol of CsI, 0.464 mmol of MAI, 0.96 mmol of FAI, 0.8 mmol of PbI2, and 0.8 mmol of SnI2.

[0152] Comparative Example 4 is similar to Example 12, except that no dopant is added in step (4), that is, the dissolved drugs are 0.16 mmol of CsI, 0.48 mmol of MAI, 0.96 mmol of FAI, 0.8 mmol of PbI2, and 0.8 mmol of SnI2.

[0153] Example 13 is similar to Example 1, except that in step (4), the drugs dissolved in 1 mL of a mixed solvent of DMF and DMSO in a volume ratio of 4:1 are 0.016 mmol of dopant 3-bromopyridine hydrochloride, 1.584 mmol of FAI, and 1.6 mmol of PbI2.

[0154] Comparative Example 5 is similar to Example 13, except that no dopant is added in step (4), and the drugs dissolved in 1 mL of a mixed solvent of DMF and DMSO in a volume ratio of 4:1 are 1.6 mmol of FAI and 1.6 mmol of PbI2.

[0155] The solar cells 100 prepared in the above-mentioned Examples 1 to 13 and Comparative Examples 1 to 5 were subjected to relevant performance tests, and the specific results are shown in Table 1.

[0156] Performance test of solar cell 100:

[0157] The test was conducted in accordance with the IEC61215 standard, using a Guangyan solar simulator and a crystalline silicon solar cell to calibrate the light intensity to the intensity of one sun (solar test standard is AM1.5). The solar cell 100 was connected to a digital source meter, and its initial photoelectric conversion efficiency and the photoelectric conversion efficiency after aging at 85°C for 1000 hours were measured under light. The ratio of the photoelectric conversion efficiency after aging at 85°C for 1000 hours to the initial photoelectric conversion efficiency was calculated. This ratio is the photoelectric conversion efficiency retention rate and is used to characterize the stability of the corresponding solar cell 100. During the aging process at 85°C for 1000 hours, the solar cell 100 was placed in a nitrogen atmosphere and dark conditions, and the H2O and O2 in the environment were maintained at ≤0.1ppm.

[0158] Table 1: Test results of solar cell performance of Examples 1 to 13 and Comparative Examples 1 to 5

[0159] From Table 1 we can see that:

[0160] (1) Analysis of the experimental data of Comparative Example 1 and Examples 1 to 4 shows that compared with the solar cell 100 not doped with the perovskite material containing a monovalent cation of the N element, the solar cell 100 doped with the perovskite material containing a monovalent cation of the N element has significantly improved initial photoelectric conversion efficiency, photoelectric conversion efficiency after aging, and stability of photoelectric conversion efficiency.

[0161] (2) Analysis of the experimental data of Comparative Example 2 and Example 1 shows that: compared with additives doped with other monovalent cations other than N-containing elements, the initial photoelectric conversion efficiency, the photoelectric conversion efficiency after aging, and the stability of the photoelectric conversion efficiency of the solar cell 100 doped with the perovskite material containing N-containing monovalent cations are significantly improved.

[0162] (3) Analysis of the experimental data of Examples 1 to 4 shows that: as the doping ratio of monovalent cations containing N elements increases, the initial photoelectric conversion efficiency, photoelectric conversion efficiency after aging, and stability of the photoelectric conversion efficiency of the solar cell 100 made of monovalent cation perovskite material containing N elements all show a trend of first increasing and then decreasing. Therefore, regulating the doping ratio of monovalent cations containing N elements is beneficial to improving the performance of related devices of the solar cell 100.

[0163] (4) Analysis of the experimental data of Example 1 and Examples 5 to 10 shows that: when the perovskite material is doped with different monovalent cations containing the N element, the initial photoelectric conversion efficiency, the photoelectric conversion efficiency after aging, and the stability of the photoelectric conversion efficiency of the corresponding solar cell 100 have certain fluctuations, but overall the photoelectric conversion efficiency and stability are improved compared with the undoped comparative example 1. Therefore, regulating the composition of the monovalent cations containing the N element is beneficial to improving the performance of related devices of the solar cell 100.

[0164] (5) Analysis of the experimental data of Example 1 and Examples 11 to 13 shows that the initial photoelectric conversion efficiency, photoelectric conversion efficiency after aging, and stability of the photoelectric conversion efficiency of the solar cell 100 using perovskite materials with different cations and / or different anions are improved compared with the corresponding undoped control. Therefore, it is shown that doping the perovskite material with monovalent cations containing the N element is applicable to a variety of perovskite materials with different cations and anions, and the relevant device performance of the solar cell 100 can be improved by regulating the composition of the cations and / or anions of the perovskite material.

[0165] (6) Analysis of the experimental data of Comparative Example 3 and Example 11 shows that: compared with the solar cell 100 not doped with the perovskite material containing a monovalent cation of the N element, the solar cell 100 doped with the perovskite material containing a monovalent cation of the N element has a lower initial photoelectric conversion efficiency, but the photoelectric conversion efficiency and the stability of the photoelectric conversion efficiency after aging are significantly improved.

[0166] (7) Analysis of the experimental data of Comparative Example 4 and Example 12 shows that compared with the solar cell 100 not doped with the perovskite material containing a monovalent cation of the N element, the solar cell 100 doped with the perovskite material containing a monovalent cation of the N element has significantly improved initial photoelectric conversion efficiency, photoelectric conversion efficiency after aging, and stability of photoelectric conversion efficiency.

[0167] (8) Analysis of the experimental data of Comparative Example 5 and Example 13 shows that compared with the solar cell 100 not doped with the perovskite material containing a monovalent cation of the N element, the solar cell 100 doped with the perovskite material containing a monovalent cation of the N element has significantly improved initial photoelectric conversion efficiency, photoelectric conversion efficiency after aging, and stability of photoelectric conversion efficiency.

[0168] (9) Analysis of the experimental data of Example 1 and Example 13 shows that: in the perovskite material including monovalent cations containing the N element, compared with the solar cell 100 including the perovskite material not including cesium cations, the initial photoelectric conversion efficiency, the photoelectric conversion efficiency after aging, and the stability of the photoelectric conversion efficiency of the solar cell 100 including the perovskite material of cesium cations are significantly improved. Therefore, regulating the type and amount of cations in the perovskite material is beneficial to improving the performance of related devices of the solar cell 100.

[0169] (10) The experimental data of Comparative Example 4 and Example 12 show that: in the perovskite material including the monovalent cation containing the N element, the methylammonium cation MA + and formamidinium cation FA + The initial photoelectric conversion efficiency, photoelectric conversion efficiency after aging, and stability of the photoelectric conversion efficiency of the solar cell 100 made of mixed cation perovskite material are significantly improved. Therefore, regulating the type and quantity of cations in the perovskite material is beneficial to improving the performance of related devices of the solar cell 100.

[0170] In summary, the embodiments of the present application improve the stability of the corresponding solar cell 100 by doping the perovskite material containing formamidinium cations with monovalent cations containing the N element.

[0171] In order to make the technical problems, technical solutions and beneficial effects solved by the embodiments of the present application clearer, the following will be further described in detail with reference to the embodiments and drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present application and its applications. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0172] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, device or unit, which can be electrical, mechanical or other forms.

[0173] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0174] The above description is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A perovskite material, wherein: The general formula of the perovskite material is M x FA y A 1-x-y BX3,0 <x≤0.1,0.5≤y<1,1-x-y≥0; Among them, M + Including monovalent cations containing nitrogen; FA + A is the formamidinium cation; + including at least one of inorganic or organic monovalent cations, B 2+ comprising at least one inorganic divalent cation, X - Includes at least one monovalent anion.

2. The perovskite material according to claim 1, wherein A + Including MA + 、Cs + , Rb + , K + DMA + , EA + , GA + One or more of; and / or B 2+ Including Pb 2+ 、Sn 2+ 、Ge 2+ 、Cd 2+ 、Sb 2+ 、Zn 2+ 、Mn 2+ , Ca 2+ One or more of; and / or X - Including I - Br - 、Cl - 、SCN - HCOO - 、CH3COO - CF3COO - 、CH3SO3 - CF3SO3 - 、CN - One or more of the .

3. The perovskite material according to claim 1 or 2, wherein The X - Including I - , the I - In X - The molar ratio of ions is greater than or equal to 0.

5.

4. The perovskite material according to any one of claims 1 to 3, wherein The A + Including Cs + and MA + One or two of the A + In M + , FA + and A + The molar ratio in the sum of the ions is less than or equal to 0.

4.

5. The perovskite material according to any one of claims 1 to 4, wherein The A + Including Cs + , the Cs + In M + , FA + and A + The molar ratio in the sum of the ions is less than or equal to 0.

4.

6. The perovskite material according to any one of claims 1 to 5, wherein The B 2+ Including Pb 2+ and Sn 2+ , the Pb 2+ In B 2+ The molar ratio in the ions is greater than 0 and less than 1.

7. The perovskite material according to any one of claims 1 to 6, wherein The radius of the monovalent cation containing the N element is larger than the radius of the formamidinium cation.

8. The perovskite material according to any one of claims 1 to 7, wherein The monovalent cation containing the N element includes one or more of a substituted or unsubstituted N-containing heterocyclic cation and a substituted or unsubstituted guanidinium cation.

9. The perovskite material according to claim 8, wherein The substituted or unsubstituted N-containing heterocyclic cation includes: one or more of a substituted or unsubstituted pyrrolyl cation, a substituted or unsubstituted pyrrolidinyl cation, a substituted or unsubstituted piperidinyl cation, a substituted or unsubstituted pyridinyl cation, a substituted or unsubstituted pyrazinyl cation, a substituted or unsubstituted piperazinyl cation, and a substituted or unsubstituted 1,2,3,4-tetrahydro-[1,3,5]triazinyl cation.

10. The perovskite material according to claim 8 or 9, wherein The monovalent cation containing N element includes one or more of substituted N heterocyclic cations and substituted guanidine cations; the substituent groups of the substituted N heterocyclic cations and the substituted guanidine cations are independently selected from -D1 and -L1-D1, Among them, L1 includes an aliphatic hydrocarbon group with 1 to 5 carbon atoms, and D1 includes one or more of methyl, cyano, carboxyl, trifluoromethanesulfonyl, phenyl, pyridyl, benzalamino, amino, acetyl, formyl, halogen, phenyl substituted with one to four halogens, benzalamino substituted with one to two halogens, and (trifluoromethyl)phenyl.

11. The perovskite material according to any one of claims 1 to 10, wherein The monovalent cation containing the N element includes one or more of a 3-bromopyridinium cation, a 1-cyanoguanidine cation, a 1-(trifluoromethanesulfonyl)guanidine cation, a 1-acetylguanidine cation, a 1,2,3,4-tetrahydro-[1,3,5]triazine cation, a 1-(2,6-dichlorobenzylideneamino)guanidine cation, and a 1-(2-chloroethyl)piperidinium cation.

12. A solar cell, wherein: include: a light absorbing layer, wherein the material forming the light absorbing layer includes a perovskite material; Wherein, the perovskite material is the perovskite material according to any one of claims 1 to 11.

13. A method for preparing a solar cell, wherein: include: A perovskite precursor solution is prepared according to the molar ratio of the components of the perovskite material forming the light absorbing layer; wherein the perovskite material is the perovskite material according to any one of claims 1 to 11; The perovskite precursor solution is formed on a substrate and solidified to obtain a light absorbing layer.

14. The method for preparing a solar cell according to claim 13, wherein: The perovskite precursor solution includes a precursor containing a monovalent cation of the N element, and the precursor containing a monovalent cation of the N element includes a salt of a monovalent cation of the N element.

15. The method for preparing a solar cell according to claim 14, wherein: The anions corresponding to the salt of the monovalent cation containing the N element include I - Br - 、Cl - 、SCN - HCOO - 、CH3COO - CF3COO - 、CH3SO3 - CF3SO3 - 、CN - One or more of.

16. The method for preparing a solar cell according to any one of claims 13 to 15, wherein: The perovskite precursor solution includes a precursor of a monovalent cation containing the N element, and the precursor of the monovalent cation containing the N element includes: 3-bromopyridine, 1-cyanoguanidine, 1-(trifluoromethanesulfonyl)guanidine, 1-acetylguanidine, 1,2,3,4-tetrahydro-[1,3,5]triazine, 1-(2,6-dichlorobenzylideneamino)guanidine, 1-(2-chloroethyl)piperidine hydrochloride, bromate, iodide, thiocyanate, formate, acetate, trifluoroacetate, trifluoromethanesulfonate, and cyanate. One or more of them.

17. An electrical device, wherein: A solar cell comprising the solar cell according to claim 12; or a solar cell prepared by the method for preparing a solar cell according to any one of claims 13 to 16.

18. A power generation device, wherein: A solar cell comprising the solar cell according to claim 12; or a solar cell prepared by the method for preparing a solar cell according to any one of claims 13 to 16.

Images