Preparation method of perovskite thin film and perovskite battery module

Abstract

The invention relates to the technical field of photovoltaic cells, and provides a preparation method of a perovskite thin film and a perovskite cell module, the preparation method comprises the following steps: preparing an ABX3 type perovskite precursor liquid, A is at least one selected from methylamine and formamidine, or a combination of at least one selected from methylamine and formamidine and at least one selected from cesium and rubidium, and B is a combination of at least one selected from cesium and rubidium; b is selected from at least one of lead, tin, germanium and bismuth, and X is selected from at least one of iodine, bromine and chlorine; an ion curing agent and the perovskite precursor solution are mixed, the chemical general formula of the ion curing agent is CY3, and C is trivalent metal cations including lutetium, aluminum and lanthanum; y is a fluorine ion; performing coating and annealing treatment on the mixed perovskite precursor solution to obtain a perovskite thin film; the ionic curing agent is used for inhibiting migration of A-site cations and X-site anions. By using the method, the problem that the working stability of a device is reduced due to migration of halogen, formamidine and methylamine ions in the perovskite film under the conditions of illumination, temperature and electric field can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic cells, and in particular to a method for preparing a perovskite film and a perovskite cell module. Background Art

[0002] Ion migration within the perovskite film is one of the main reasons for the instability of perovskite materials under light. As the light intensity increases, the ion migration behavior within the perovskite film becomes more obvious, leading to abnormal behaviors such as self-polarization effect, halide decomposition, and very slow photoelectric response process under light, which further aggravates the degradation of the material and reduces the long-term working stability of the device, thus affecting the overall performance and service life of the battery.

[0003] The migrating ions in perovskite films mainly refer to halogen anions (such as chloride ions, bromide ions, iodide ions), formamidinium ions and methylamine ions. These ions will migrate under certain conditions (such as temperature, light, electric field, etc.), thus affecting the performance and stability of perovskite films. The migration of halogen anions in perovskite films is particularly significant, and the migration of halogen anions will change the band gap and absorption spectrum of perovskite films, thereby affecting the photoelectric conversion efficiency of perovskite cells; the migration of formamidinium ions and methylamine ions will cause the decomposition of perovskite films and reduce the working stability of photovoltaic devices.

[0004] In view of the above problems, the present invention provides a solution. Summary of the invention

[0005] The purpose of the present invention is to solve the problem that the halogen, formamidine and methylamine ions in the existing perovskite film can migrate under the conditions of light, temperature and electric field, thereby causing a serious decrease in the working stability of the photovoltaic device. A method for preparing a perovskite film and a perovskite battery module are provided. Adding an ion curing agent to a perovskite precursor solution can increase the migration activation energy of the A-site cations and the X-site anions in the perovskite film, thereby slowing down the migration of the A-site cations and the X-site anions, and improving the working stability of the perovskite photovoltaic device.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for preparing a perovskite film comprises the following steps:

[0008] S1. Prepare an ABX3-type perovskite precursor solution, wherein A is selected from at least one of methylamine and formamidine, or A is a combination of at least one of methylamine and formamidine and at least one of cesium and rubidium, B is selected from at least one of lead, tin, germanium and bismuth, and X is selected from at least one of iodine, bromine and chlorine;

[0009] S2, adding an ionic curing agent to the perovskite precursor solution and mixing them evenly, wherein the chemical formula of the ionic curing agent is CY3, wherein C is a trivalent metal cation including lutetium, aluminum and lanthanum; and Y is a fluoride ion;

[0010] S3, coating the perovskite precursor solution to which the ion curing agent is added on the top surface of the substrate, and obtaining a perovskite film by annealing;

[0011] The ionic curing agent is used to inhibit the migration of A-site cations and X-site anions in the perovskite film.

[0012] As a preparation method of a perovskite film provided by the present invention, the C-site cations in the ionic curing agent can be combined with the X-site anions in the perovskite film through electrostatic interaction, and the Y-site anions in the ionic curing agent can be combined with the A-site cations in the perovskite film through hydrogen bonds, thereby increasing the activation energy required for the migration of the X-site anions and the A-site cations, and reducing the migration capacity of the X-site anions and the A-site cations. The diffusion of the A-site cations and the X-site anions in the perovskite film is reduced, the loss of the A-site cations and the X-site anions in the perovskite film is avoided, and the decomposition of the perovskite film and the reaction with other functional layers caused by the diffusion of the A-site cations and the X-site anions in the perovskite film out of the perovskite film is also reduced, and the working stability of the device is improved.

[0013] Therefore, the ionic curing agent is added to the perovskite precursor solution to prepare the perovskite film. Compared with the perovskite layer to which the ionic curing agent is not added, the ionic curing agent can increase the migration activation energy of the A-site cations and the X-site anions in the perovskite film, thereby slowing down the migration of the A-site cations and the X-site anions and improving the working stability of the perovskite photovoltaic device.

[0014] As a preferred embodiment of the present invention, the molar amount of the ionic curing agent added in step S2 is 0.05%-0.3% of the molar amount in the perovskite precursor solution.

[0015] As a preferred embodiment of the present invention, the coating method in step S3 is blade coating or slit coating, and the thickness of the perovskite film obtained by blade coating or slit coating is 500-900 nm.

[0016] As a preferred embodiment of the present invention, the temperature of the annealing treatment in step S3 is 100-180° C., and the annealing time is 10-40 min.

[0017] A perovskite battery module comprises a formal structure or a trans structure. The structure of the perovskite battery module with the formal structure from bottom to top is a substrate, an electron transport layer, a perovskite film prepared by the above-mentioned method for preparing a perovskite film, a hole transport layer and a metal electrode; the structure of the perovskite battery module with the trans structure from bottom to top is a substrate, a hole transport layer, a perovskite film prepared by the above-mentioned method for preparing a perovskite film, an electron transport layer and a metal electrode.

[0018] The present invention provides a perovskite battery module, using the perovskite film prepared by a perovskite film preparation method, compared with the ABX3 type perovskite layer in the perovskite battery module commonly used now, the ion curing agent added to the perovskite film can increase the migration activation energy of the X-position anion and the A-position cation, and improve the stability of the perovskite lattice. Therefore, the ion curing agent can slow down the migration of the A-position cation and the X-position anion, improve the stability of the perovskite film, and reduce the adverse effects on other transport layers caused by the ion migration of the A-position cation and the X-position anion in the perovskite film, and finally improve the working stability of the photovoltaic device.

[0019] As a preferred embodiment of the present invention, when the perovskite battery module adopts a trans structure, it further comprises a hole blocking layer, and the hole blocking layer is arranged between the electron transport layer and the metal electrode.

[0020] As a preferred embodiment of the present invention, the material of the hole blocking layer is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), and the thickness of the hole blocking layer is 5 to 10 nm.

[0021] As a preferred embodiment of the present invention, the hole transport layer in the trans-structured perovskite battery module comprises nickel oxide (NiO x ), 3-hexylthiophene (P3HT), cuprous thiocyanate (CuSCN), polytriarylamine (PTAA), [2-(9h-carbazole-9-yl)ethyl]phosphonic acid (2PACZ), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACZ), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACZ) and [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACZ); the material of the hole transport layer in the perovskite battery module of the formal structure includes nickel oxide (NiO x ) or polytriarylamine (PTAA).

[0022] As a preferred embodiment of the present invention, the substrate comprises indium tin oxide (ITO) glass, fluorine-doped tin oxide (FTO) glass or aluminum-doped zinc oxide (AZO) glass.

[0023] As a preferred embodiment of the present invention, the material of the metal electrode is selected from one of gold, silver, copper and aluminum, and the thickness of the metal electrode is 100 to 500 nm.

[0024] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0025] 1. A method for preparing a perovskite film, wherein an ionic curing agent is added to a perovskite precursor solution, wherein the ionic curing agent can increase the migration activation energy of the A-site cations and the X-site anions in the perovskite film, thereby slowing down the migration of the A-site cations and the X-site anions, making the perovskite film more uniform and having better film quality, reducing the defect sites on the surface and inside of the perovskite film, and improving the charge transfer efficiency.

[0026] 2. A perovskite battery module, which uses a perovskite film with an added ion curing agent to reduce the diffusion of A-site cations and X-site anions out of the perovskite film, improves the phase stability of the perovskite film, reduces the reaction with other layers, and ultimately improves the working stability of the photovoltaic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a preparation flow chart of a method for preparing a perovskite thin film;

[0028] Figure 2 The schematic diagram of the structure of a perovskite battery adopting a trans-structured perovskite battery;

[0029] Figure 3 It is a JV curve diagram of a trans-structured perovskite cell with different amounts of LaF3 added to the perovskite cell;

[0030] Figure 4 It is a JV curve diagram of a trans-structured perovskite cell with different amounts of LuF3 added to the perovskite cell;

[0031] Figure 5 It is a JV curve of a trans-structured perovskite cell with different amounts of AlF3 added to the perovskite cell;

[0032] Figure 6 This is a stability test diagram of a trans-structured perovskite battery with and without an ion curing agent added;

[0033] Icon: 1-substrate; 2-hole transport layer; 3-perovskite film; 4-electron transport layer; 5-hole blocking layer; 6-metal electrode. DETAILED DESCRIPTION

[0034] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0035] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] Example 1

[0037] like Figure 1 As shown, a method for preparing a perovskite film adopted in the present invention comprises the following steps:

[0038] S1. Prepare an ABX3-type perovskite precursor solution, wherein A is selected from at least one of methylamine and formamidine, or A is a combination of at least one of methylamine and formamidine and at least one of cesium and rubidium, B is selected from at least one of lead, tin, germanium and bismuth, and X is selected from at least one of iodine, bromine and chlorine;

[0039] S2, adding an ionic curing agent to the perovskite precursor solution and mixing them evenly, wherein the chemical formula of the ionic curing agent is CY3, wherein C is a trivalent metal cation including lutetium, aluminum and lanthanum; and Y is a fluoride ion;

[0040] S3, coating the perovskite precursor solution to which the ion curing agent is added on the top surface of the substrate, and obtaining the perovskite film 3 by annealing;

[0041] The ionic curing agent is used to inhibit the migration of the A-site cations and the X-site anions in the perovskite film 3 .

[0042] Furthermore, the molar amount of the ionic curing agent added in step S2 is 0.05% to 0.3% of the molar amount in the perovskite precursor solution.

[0043] Furthermore, the coating method in step S3 is blade coating or slit coating, and the thickness of the perovskite film 3 obtained by blade coating or slit coating is 500-900 nm.

[0044] Furthermore, the annealing treatment in step S3 is performed at a temperature of 100 to 180° C. and for a time of 10 to 40 minutes.

[0045] The perovskite film 3 prepared by adding the ionic curing agent to the perovskite precursor solution, compared with the perovskite layer without adding the ionic curing agent, the ionic curing agent can increase the migration activation energy of the A-site cations and the X-site anions in the perovskite film 3, thereby slowing down the migration of the A-site cations and the X-site anions, and improving the working stability of the perovskite photovoltaic device.

[0046] Example 2

[0047] A perovskite battery module adopted by the present invention comprises a formal structure or a trans structure. The structure of the perovskite battery module with the formal structure from bottom to top is a substrate 1, an electron transport layer 4, a perovskite film 3 prepared by the method for preparing a perovskite film as described in Example 1, a hole transport layer 2 and a metal electrode 6; the structure of the perovskite battery module with the trans structure from bottom to top is a substrate 1, a hole transport layer 2, a perovskite film 3 prepared by the method for preparing a perovskite film as described in Example 1, an electron transport layer 4 and a metal electrode 6.

[0048] Furthermore, when the perovskite battery module adopts a trans structure, it also includes a hole blocking layer 5 , and the hole blocking layer 5 is arranged between the electron transport layer 4 and the metal electrode 6 .

[0049] Furthermore, the material of the hole blocking layer 5 is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), and the thickness of the hole blocking layer 5 is 5-10 nm.

[0050] Furthermore, the hole transport layer 2 in the trans-structured perovskite battery module comprises nickel oxide (NiO x ), 3-hexylthiophene (P3HT), cuprous thiocyanate (CuSCN), polytriarylamine (PTAA), [2-(9h-carbazole-9-yl)ethyl]phosphonic acid (2PACZ), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACZ), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACZ) and [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACZ) One or more; the hole transport layer 2 in the formally structured perovskite battery module contains nickel oxide (NiOx) or polytriarylamine (PTAA).

[0051] Furthermore, the substrate 1 comprises indium tin oxide (ITO) glass, fluorine-doped tin oxide (FTO) glass or aluminum-doped zinc oxide (AZO) glass.

[0052] Furthermore, the material of the metal electrode 6 is selected from one of gold, silver, copper and aluminum, and the thickness of the metal electrode 6 is 100-500 nm.

[0053] like Figure 2 As shown, in this embodiment, the perovskite battery module adopts a trans structure, and the preparation process of the perovskite battery module is as follows. A P1 line is etched on the substrate 1, and the substrate 1 is made of fluorine-doped tin oxide (FTO) glass. The substrate is ultrasonically cleaned with anhydrous ethanol for 60 minutes. After the substrate 1 is fully dried in an oven, the substrate 1 is treated with ultraviolet-ozone for 20 minutes; a 25nm thick NiO layer is deposited on the top surface of the substrate 1 by magnetron sputtering. x The layer serves as the hole transport layer 2.

[0054] Preparation of the perovskite precursor solution: Weigh a certain amount of PbI2, PbBr2, MAI, FAI, CsI and MABr respectively and dissolve them in a mixed solution of N,N-dimethylformamide and N-methylpyrrolidone to obtain the perovskite precursor solution. Preparation of the perovskite film 3: Add the ionic curing agent to the perovskite precursor solution and stir evenly. Apply the perovskite precursor solution to which the ionic curing agent is added on the top surface of the hole transport layer 2 by blade coating or slit coating, and perform film forming treatment on the perovskite precursor solution to which the ionic curing agent is added by vacuum assisted crystallization. The vacuum degree of the vacuum assisted crystallization method is 10 -3 Pa, the annealing temperature of the perovskite film 3 is 100° C., and the annealing time is 20 min. The thickness of the obtained perovskite film 3 is 500 nm.

[0055] The material of the electron transport layer 4 in this embodiment is C 60 , the electron transport layer 4 is deposited on the top surface of the perovskite layer by vacuum evaporation, and the thickness of the electron transport layer 4 is 30nm. In this embodiment, the hole blocking layer 5 is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), and the thickness of the hole blocking layer 5 is 8nm. The P2 line adjacent to P1 is etched with green light, and the laser power is adjusted to ensure that the laser only cuts off the hole transport layer 2, the perovskite film 3, the electron transport layer 4 and the hole blocking layer 5 without damaging the substrate 1.

[0056] The metal electrode 6 is made of silver and is deposited on the top surface of the hole blocking layer 5 by vacuum evaporation to obtain the perovskite battery module. The P3 line is etched with green light, and the laser power is adjusted to ensure that the laser only cuts the thin film between the metal electrode 6 and the hole transport layer 2 without damaging the substrate.

[0057] Different amounts of LaF3, LuF3 and AlF3 were added to the perovskite precursor solution with a concentration of 1 M to prepare a trans-structured perovskite battery module.

[0058] like Figure 3 As shown, the optimal addition concentration of LaF3 is 0.3 mg, and the efficiency of the trans-structured perovskite battery module is the highest; Figure 4 As shown, the optimal addition concentration of LuF3 is 0.4 mg, and the efficiency of the trans-structured perovskite battery module is the highest; Figure 5 As shown, the optimal addition concentration of AlF3 is 0.15 mg, and the efficiency of the trans-structured perovskite battery module is the highest; Figure 5 It can be seen that the photoelectric conversion efficiency of the trans-structured perovskite battery module with the addition of the ionic curing agent is significantly improved compared with the photoelectric conversion efficiency of the trans-structured perovskite battery module without the addition of the ionic curing agent.

[0059] The trans-structured perovskite battery module using the optimal addition concentration of the ionic curing agent LaF3, LuF3 and AlF3 and the trans-structured perovskite battery module without the ionic curing agent were placed under the test conditions of temperature of 50-60°C and humidity of 50-60% for 1000 hours, and then the stability test was carried out using a simulated light source system. Figure 6 As shown, within the first 300 hours, the trans-structured perovskite battery module using LaF3, LuF3 and AlF3 as the ion curing agent and the trans-structured perovskite battery module without adding the ion curing agent did not decay significantly; after 300 hours, the trans-structured perovskite battery module without adding the ion curing agent had a significant performance decay trend, and the trans-structured perovskite battery module using LaF3 as the ion curing agent had a relatively gentle decay trend but with large fluctuations; the trans-structured perovskite battery module using LuF3 and AlF3 as the ion curing agent had a gentle decay trend and both had less performance decay than the trans-structured perovskite battery module using LaF3, and the trans-structured perovskite battery module using AlF3 as the ion curing agent had the least performance decay. Therefore, using LaF3, LuF3 and AlF3 as the ion curing agent can significantly improve the stability of the trans-structured perovskite battery module.

[0060] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a perovskite film, characterized in that: The following steps are involved: S1. Prepare an ABX3-type perovskite precursor solution, wherein A is selected from at least one of methylamine and formamidine, or A is a combination of at least one of methylamine and formamidine and at least one of cesium and rubidium, B is selected from at least one of lead, tin, germanium and bismuth, and X is selected from at least one of iodine, bromine and chlorine; S2, adding an ionic curing agent to the perovskite precursor solution and mixing them evenly, wherein the chemical formula of the ionic curing agent is CY3, wherein C is a trivalent metal cation including lutetium, aluminum and lanthanum; and Y is a fluoride ion; S3, coating the perovskite precursor solution to which the ion curing agent is added on the top surface of the substrate, and obtaining a perovskite film by annealing; The ionic curing agent is used to inhibit the migration of A-site cations and X-site anions in the perovskite film.

2. The method for preparing a perovskite thin film according to claim 1, characterized in that: The molar amount of the ionic curing agent added in step S2 is 0.05% to 0.3% of the molar amount in the perovskite precursor solution.

3. The method for preparing a perovskite thin film according to claim 1, characterized in that: The coating method in step S3 is blade coating or slit coating. The thickness of the perovskite film obtained by blade coating or slit coating is 500-900 nm.

4. The method for preparing a perovskite thin film according to claim 1, characterized in that: The temperature of the annealing treatment in step S3 is 100-180° C., and the annealing time is 10-40 minutes.

5. A perovskite battery module, comprising a regular structure or a trans structure, characterized in that: The structure of the perovskite battery module with a formal structure from bottom to top is a substrate, an electron transport layer, a perovskite film prepared by the method for preparing a perovskite film as described in any one of claims 1 to 4, a hole transport layer and a metal electrode; the structure of the perovskite battery module with a transverse structure from bottom to top is a substrate, a hole transport layer, a perovskite film prepared by the method for preparing a perovskite film as described in any one of claims 1 to 4, an electron transport layer and a metal electrode.

6. A perovskite battery module according to claim 5, characterized in that: When the perovskite battery module adopts a trans structure, it also includes a hole blocking layer, and the hole blocking layer is arranged between the electron transport layer and the metal electrode.

7. A perovskite battery module according to claim 6, characterized in that: The material of the hole blocking layer is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), and the thickness of the hole blocking layer is 5-10 nm.

8. A perovskite battery module according to any one of claims 5 to 7, characterized in that: The hole transport layer in the trans-structured perovskite battery module includes nickel oxide (NiO x ), 3-hexylthiophene (P3HT), cuprous thiocyanate (CuSCN), polytriarylamine (PTAA), [2-(9h-carbazole-9-yl)ethyl]phosphonic acid (2PACZ), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACZ), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACZ) and [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACZ); the material of the hole transport layer in the perovskite battery module of the formal structure includes nickel oxide (NiO x ) or polytriarylamine (PTAA).

9. A perovskite battery module according to any one of claims 5 to 7, characterized in that: The substrate comprises indium tin oxide (ITO) glass, fluorine-doped tin oxide (FTO) glass or aluminum-doped zinc oxide (AZO) glass.

10. A perovskite battery module according to any one of claims 5 to 7, characterized in that: The material of the metal electrode is selected from one of gold, silver, copper and aluminum, and the thickness of the metal electrode is 100-500 nm.

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