Preparation of perovskite crystal film, perovskite cell, preparation of perovskite cell and photovoltaic system

Abstract

The embodiment of the invention provides preparation of a perovskite crystal thin film, a perovskite cell, preparation of the perovskite cell and a photovoltaic system. According to the preparation method of the perovskite crystal thin film provided by the embodiment of the invention, the large-area perovskite crystal thin film can be prepared, so that the preparation method can be applied to preparation of a perovskite battery, a large-area inverted-structure (P-I-N) perovskite battery without a hole transport layer can be prepared, and the preparation method is low in production cost, easy to operate and suitable for industrial production. A large-area perovskite cell without a hole transport layer can be provided.

Description

Technical Field

[0001] The present application relates to the technical field of perovskite cells, and specifically to the preparation of perovskite crystal films, perovskite cells and their preparation, and photovoltaic systems. Background Art

[0002] Inverted structure (PIN) perovskite cells have gradually attracted market attention due to their excellent photoelectric performance and higher stability, but the commercialization of PIN perovskite cells still faces many challenges, such as the preparation and performance assurance of the hole transport layer. The hole transport layer is located between the perovskite layer and the transparent conductive layer, which can avoid the direct contact between the perovskite layer and the transparent conductive layer to form a Schottky contact defect, resulting in difficulty in hole transport; the material selection of the hole transport layer includes polymers, inorganic P-type semiconductors and small molecule self-assembly materials, but the preparation of the hole transport layer of the above three materials faces different problems, which will lead to a significant increase in the production cost of perovskite cells, or poor consistency, which is not conducive to the commercial application of PIN perovskite cells.

[0003] In order to solve the above technical problems, the industry has proposed PIN perovskite cells without a hole transport layer. However, current technical means can only produce small-area PIN perovskite cells, which are still not suitable for commercial applications. Summary of the invention

[0004] In view of this, the embodiments of the present application provide the preparation of perovskite crystal film, perovskite cell and its preparation and photovoltaic system. The preparation method of perovskite crystal film provided in the embodiments of the present application can prepare a large-area perovskite crystal film, which can be applied to the preparation of perovskite cell, and can prepare a large-area PIN perovskite cell without hole transport layer, and the production cost is low and easy to operate, and a large-area perovskite cell without hole transport layer can be provided.

[0005] A first aspect of an embodiment of the present application provides a method for preparing a perovskite crystal film, comprising:

[0006] A perovskite precursor solution is placed on the surface of the substrate and allowed to stand in a vacuum environment, and then an annealing treatment is performed to obtain a perovskite crystal film on the surface of the substrate;

[0007] Wherein, the perovskite precursor solution includes a perovskite material and a self-assembled single-molecule hole transport material.

[0008] The above preparation process has strong reliability, high flexibility and high production efficiency, and can be used to prepare large-area perovskite crystal films.

[0009] A second aspect of the embodiment of the present application provides a method for preparing a perovskite battery, comprising:

[0010] A perovskite precursor solution is placed on the surface of a conductive substrate and allowed to stand in a vacuum environment, and then an annealing treatment is performed to form a perovskite crystal film on the surface of the conductive substrate to obtain a perovskite battery;

[0011] Wherein, the perovskite precursor solution includes a perovskite material and a self-assembled single-molecule hole transport material.

[0012] The above preparation method has strong process reliability, high flexibility and high production efficiency, and can be used to prepare large-area perovskite cells without hole transport layers, and the prepared perovskite cells have high consistency.

[0013] A third aspect of the embodiment of the present application provides a perovskite battery, comprising:

[0014] It includes a conductive substrate and a perovskite crystal layer arranged in layers, wherein the perovskite crystal layer includes a first sublayer and a second sublayer arranged in layers, the second sublayer is arranged close to the transparent conductive substrate, and the second sublayer includes perovskite crystals and a self-assembled single-molecule hole transport material dispersed between the perovskite crystals;

[0015] The area of ​​the perovskite cell in the second direction is ≥10 4 mm 2 , the second direction is perpendicular to the stacking direction of the conductive substrate and the perovskite crystal layer.

[0016] The perovskite cell provided in the embodiment of the present application has a low preparation cost, and compared with the perovskite cell containing a hole transport layer in the related art, the perovskite cell provided in the embodiment of the present application is thinner when achieving a comparable photoelectric conversion efficiency. More importantly, the embodiment of the present application provides for the first time a large area (≥10 4 mm 2 )'s hole-transport-layer-free perovskite cell can be commercially applied.

[0017] The fourth aspect of the embodiment of the present application provides a photovoltaic system, including an electrically connected photovoltaic module and an energy storage system, wherein the photovoltaic module includes a perovskite battery prepared by the preparation method provided in the second aspect of the embodiment of the present application, or includes a perovskite battery provided in the third aspect of the embodiment of the present application. Due to the perovskite battery provided in the embodiment of the present application, the above photovoltaic system has strong market competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the principle of extrusion deposition of a self-assembled single-molecule hole transport material during a static state in a method for preparing a perovskite crystal film provided in an embodiment of the present application;

[0019] Figure 2This is a process flow chart for preparing the perovskite battery of Example 1 of the present application;

[0020] Figure 3 A schematic diagram of the structure of a perovskite battery provided in one embodiment of the present application;

[0021] Figure 4 A schematic diagram of the structure of a perovskite cell provided in another embodiment of the present application;

[0022] Figure 5 A schematic diagram of the P1, P2, and P3 lines of the perovskite cell prepared in Example 1 of the present application;

[0023] Figure 6 This is a photo of the perovskite cell prepared in Example 1 of the present application;

[0024] Figure 7 The current-voltage curves obtained by performing IV tests on the perovskite cells of Example 1 to Comparative Example 2 of the present application. DETAILED DESCRIPTION

[0025] According to the functional classification, the inverted structure (PIN) perovskite cell generally includes a stacked anode layer, a hole transport layer, a light absorption layer (i.e., a perovskite crystal layer), an electron transport layer, and a cathode layer, wherein the anode layer is a transparent conductive layer. In a PIN structure perovskite cell, if the light absorption layer is in direct contact with the anode layer, a Schottky contact will be formed, which can easily lead to difficulties in hole transport. Therefore, conventional PIN structure perovskite cells generally have a hole transport layer, such as a polymer hole transport layer, an inorganic P-type semiconductor hole transport layer, or a self-assembled monolayer (SAMs) hole transport layer. However, the preparation process of the inorganic P-type semiconductor hole transport layer has high energy consumption and high cost, or the consistency of the polymer hole transport layer or the SAMs hole transport layer is relatively poor, which will lead to poor battery consistency, which is also not conducive to the commercial application of the battery. The industry has proposed the concept of PIN perovskite cells without a hole transport layer. However, the preparation of the above-mentioned structured cells in the related technology requires the use of a dynamic extraction process of an anti-solvent, which can only remain in the laboratory stage. Moreover, the effective area of ​​the PIN perovskite cells without a hole transport layer that can be prepared by the above method does not exceed 1cm. 2 , and cannot be used commercially.

[0026] In order to solve the above technical problems, the embodiment of the present application first provides a method for preparing a perovskite crystal film, which can produce a large-area perovskite crystal film, and then can be used to provide a method for preparing a perovskite battery.

[0027] Specifically, the present application provides a method for preparing a perovskite crystal film, comprising:

[0028] A perovskite precursor solution is placed on the surface of the substrate and allowed to stand in a vacuum environment, and then an annealing treatment is performed to obtain a perovskite crystal film on the surface of the substrate;

[0029] Wherein, the perovskite precursor solution includes a perovskite material and a self-assembled single-molecule hole transport material.

[0030] For the convenience of description, the above-mentioned method for preparing the perovskite crystal film is divided into steps S01-S03 for description:

[0031] S01. Disposing a perovskite precursor solution on the surface of a substrate to form a perovskite coating; wherein the perovskite precursor solution includes a perovskite material and a self-assembled monolayer (SAMs) hole transport material;

[0032] S02, placing the substrate with the perovskite coating in a vacuum environment and allowing it to stand, so as to cause the solvent to evaporate quickly, thereby forming a perovskite crystal thin film preform on the surface of the substrate;

[0033] S03, annealing the substrate with the perovskite crystal film preform, so that the perovskite crystal film preform is transformed into a perovskite crystal film.

[0034] In step S01, a perovskite precursor solution is disposed on the surface of the substrate to form a perovskite coating. It can be understood that the perovskite material and the SAMs hole transport material are mixed and dispersed in the perovskite coating. In particular, after the SAMs hole transport material is mixed with the perovskite material, based on the good wettability of the perovskite material to the substrate, the problem of low wettability of the SAMs hole transport material to the substrate can be effectively reduced, so that the perovskite coating can fully wet the surface of the transparent conductive substrate with good uniformity.

[0035] More importantly, in step S02, see Figure 1 Under the low pressure conditions brought by the vacuum environment, the perovskite material in the perovskite coating crystallizes to form a perovskite intermediate phase, and the above crystallization process is carried out from the surface of the perovskite coating facing away from the substrate toward the substrate. The above crystallization process can force the SAMs hole transport material (molecule) to be squeezed and deposited on the side of the perovskite coating close to the substrate, and the concentration is higher on the side close to the substrate, thereby forming a perovskite crystal film preform on the surface of the substrate. The above avoids the limitation of the area of ​​the perovskite coating by the anti-solvent dynamic extraction process in the related art, and can achieve large area (for example, an area greater than 10 4 mm 2) and can effectively improve the uniformity of the deposition of SAMs hole transport materials and the uniformity of the perovskite intermediate phase, thereby facilitating the preparation of a perovskite crystal film with high crystal quality and high uniformity. It should be noted that the perovskite intermediate phase refers to a crystalline perovskite, but its crystal configuration is different from the crystal configuration of the perovskite crystal in the final perovskite cell.

[0036] After the above perovskite crystal thin film preform is annealed in step S03, the crystal form of the perovskite intermediate phase changes, and a cubic phase perovskite crystal thin film that can achieve light absorption effect is obtained.

[0037] The above preparation method has strong process reliability, high flexibility, and high production efficiency. It can be used to prepare large-area PIN perovskite cells without hole transport layers, and the obtained perovskite cells have high consistency. It should be noted that the preparation method of the perovskite crystal film provided in the embodiment of the present application can also prepare a small-area perovskite crystal film. The present application has no restrictions on the area of ​​the perovskite crystal film to be prepared. In some embodiments of the present application, the substrate has an area ≥10 4 mm 2 That is, in some embodiments, the area of ​​the obtained perovskite crystal film is ≥ 10 4 mm 2 In some specific embodiments, the area of ​​the prepared perovskite crystal film can be, for example, 100 mm×100 mm, 300 mm×300 mm, 300 mm×400 mm, 1.2 m×0.6 m, or 2.4 m×1.2 m.

[0038] In some embodiments of the present application, the preparation of the perovskite precursor solution in step S01 includes:

[0039] S11, add SAMs hole transport material to the perovskite solution, mix, and obtain a perovskite precursor solution. In some specific embodiments, a solution containing SAMs hole transport material is added to the perovskite solution, mixed, and a perovskite precursor solution is obtained. In the embodiment of the present application, the solvent used to dissolve and disperse the SAMs hole transport material includes but is not limited to at least one of N, N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), 2-mercaptoethanol (2ME), and N-methylpyrrolidone (NMP). It can be understood that at this time, the perovskite precursor solution also contains a solution, so under the vacuum environment of step S02, the volatilization of the solvent and the formation of the perovskite mesophase squeeze the SAMs hole transport material together, which is more conducive to forcing the SAMs hole transport material to be deposited on the side close to the substrate, and improving the crystal quality of the perovskite on the side away from the substrate during annealing, thereby facilitating the improvement of the photoelectric conversion efficiency of the final perovskite cell.

[0040] Considering that the concentration of the SAMs hole transport material in the second sublayer of the light absorption layer of the final perovskite cell needs to be controlled within an appropriate range to ensure the hole transport effect of the second sublayer, and to reduce or avoid the risk of reduced quality of the perovskite crystal caused by the high concentration of the SAMs hole transport material in the first sublayer as much as possible, in some embodiments of the present application, the content of the SAMs hole transport material in the perovskite precursor solution is 0.01mg / L-10mg / L. Specifically, the content of the SAMs hole transport material in the perovskite precursor solution can be, for example, 0.01mg / L, 0.02mg / L, 0.05mg / L, 0.1mg / L, 0.5mg / L, 0.8mg / L, 1mg / L, 2mg / L, 3mg / L, 4mg / L, 5mg / L, 6mg / L, 7mg / L, 8mg / L, 9mg / L, 10mg / L, etc.

[0041] In the embodiment of the present application, in step S01, arranging the perovskite precursor solution on the substrate includes: coating the perovskite precursor solution on the surface of the substrate. The coating can be any process known to technicians in the field. Considering that a large area of ​​perovskite cells need to be prepared in some cases, the coating process includes but is not limited to at least one of blade coating, slit coating, etc. For details, please refer to Figure 2 , a coating head 1 is used to place a perovskite precursor solution on the surface of the substrate 3 to obtain a perovskite coating 2; wherein the direction of the arrow is the coating direction, and then the substrate 5 with the perovskite coating is placed in a vacuum environment 4 and allowed to stand. It should also be noted that Figure 2 6 is a vacuum pump for creating a vacuum environment.

[0042] In some embodiments of the present application, in step S01, the vacuum degree of the vacuum environment is 5Pa-0.1MPa. In some specific embodiments, the vacuum degree of the vacuum environment is 5Pa-50 Pa. Suitable vacuum degrees are conducive to the rapid volatilization of the solvent in the applied perovskite coating, while the SAMs hole transport material is quickly deposited on the side of the perovskite coating close to the substrate, and the crystallization rate of the perovskite material and the volatilization rate of the solvent are controlled within a suitable range, which is conducive to improving the crystal quality of the perovskite mesophase. Specifically, the vacuum degree of the vacuum environment can be, for example, 5Pa, 10Pa, 20Pa, 30Pa, 40Pa, 50Pa, 60Pa, 70Pa, 80Pa, 90Pa, 100Pa, 200Pa, 300Pa, 400Pa, 500Pa, 600Pa, 700Pa, 800Pa, 900Pa, 0.1MPa, etc.

[0043] In some embodiments of the present application, in step S01, the substrate with the perovskite coating may be placed in a cavity, and then evacuated to a vacuum degree of 5Pa-0.1MPa at a vacuum rate of 0.1L / s-10L / s.

[0044] In some embodiments of the present application, the duration of standing is ≥1 min. In this way, the SAMs hole transport material can be quickly deposited on the side of the perovskite coating close to the substrate, ensuring that in the final perovskite crystal film, the hole transport performance of the first sublayer is good, and the perovskite crystal quality of the second sublayer is high. In addition, considering that the maintenance time of the perovskite mesophase may affect the quality of the final perovskite crystal, in some specific embodiments, the duration of standing is also controlled to be ≤20 min. Therefore, in some specific embodiments, the duration of standing is 1 min-20 min. Specifically, the duration of standing can be, for example, 1 min, 2 min, 5 min, 8 min, 10 min, 12 min, 15 min, 18 min, 20 min, etc.

[0045] In some specific embodiments of the present application, in step S01, the substrate with the perovskite coating is placed in a vacuum environment of 5Pa-0.1MPa for 1min-20min.

[0046] In the embodiment of the present application, the perovskite material can be any perovskite material known in the art that is suitable for the light absorption layer of the perovskite cell. Specifically, the perovskite material includes but is not limited to ABX3, A includes CH 3 NH 3+ HC(NH 2 ) 2+ , Cs + and Rb + One or more of, B includes Pb 2+ and / or Sn 2+ , X includes a halogen anion; the halogen anion may be, for example, Cl - Br - ,I - wait.

[0047] In the embodiment of the present application, the SAMs hole transport material can be a SAMs hole transport material known in the art and suitable for perovskite cells. Specifically, the SAMs hole transport material includes but is not limited to (2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl)phosphonic acid (MeO-2PACz), (2-(4-(di(4-methoxy)amino)phenyl)-1-cyanoethylene)phosphonic acid (MPA-CPA), (4-(2,7-dibromo-9,9-dimethylacridine-10(9H)-yl)butyl)phosphonic acid (DMAcPA), (2-(9H-carbazole-9-yl)ethyl)phosphonic acid (2PACz), (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid (Me-4PACz), One or more of (2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl)phosphonic acid (Me-2PACz), (4-(3,6-dibromo-9H-carbazole-9-yl)butyl)phosphonic acid (Br-4PACz), (2-(3,6-dibromo-9H-carbazole-9-yl)ethyl)phosphonic acid (Br-2PACz), triphenylphosphinothioic acid 2-fluorobenzoic acid (TBT-FBA), (4-(7H-dibenzo[c,g]carbazole-7-yl)butylphosphonic acid (4PADCB) and (4-((7H)-dibenzocarbazole-7-yl)ethyl)phosphonic acid (2PADCB).

[0048] In the embodiment of the present application, in step S03, the annealing treatment may be performed using processes and parameters well known to those skilled in the art, and the present application does not impose any limitation thereto; for example, annealing may be performed at 100° C.-150° C. for 10-30 minutes.

[0049] The present application also provides a method for preparing a perovskite battery, comprising:

[0050] A perovskite precursor solution is placed on the surface of a conductive substrate and allowed to stand in a vacuum environment, followed by annealing to form a perovskite crystal layer on the surface of the conductive substrate to obtain a perovskite cell; wherein the perovskite precursor solution includes a perovskite material and a self-assembled monolayer hole transport material.

[0051] Specifically, for the convenience of description, it can also be divided into the following steps:

[0052] S11, placing a perovskite precursor solution on the surface of the conductive substrate to form a perovskite coating to obtain a first preform; wherein the perovskite precursor solution includes a perovskite material and a self-assembled monolayer (SAMs) hole transport material;

[0053] S12, placing the first preform in a vacuum environment and leaving it to stand for a first period of time to obtain a second preform;

[0054] S13, annealing the second preform to form a perovskite crystal layer on the surface of the conductive substrate to obtain a perovskite cell.

[0055] It can be understood that the preparation method of the perovskite battery provided in the embodiment of the present application is essentially applied to the preparation method of the aforementioned perovskite crystal film provided in the embodiment of the present application, and the principles are the same, so it will not be repeated here. In addition, the preparation method of the perovskite battery provided in the embodiment of the present application can ultimately produce a light absorption layer with a double-layer structure, for example: the light absorption layer is divided into a perovskite crystal layer (first sublayer) on the side away from the conductive substrate, and a sublayer (second sublayer) close to the conductive substrate on which both perovskite crystals and SAMs hole transport materials are dispersed; since the SAMs hole transport material shows P-type conductor properties relative to the perovskite crystal, the final perovskite battery can work normally. The above avoids the limitation of the area of ​​the perovskite precursor layer by the anti-solvent dynamic extraction process in the related art, and can achieve large areas (for example, an area greater than 10 4 mm 2 ) can be used to prepare a PIN structured perovskite battery without a perovskite transport layer, and can effectively improve the uniformity of the deposition of SAMs hole transport materials and the uniformity of the perovskite intermediate phase, thereby facilitating the preparation of a PIN perovskite battery without a hole transport layer with high consistency.

[0056] The above-mentioned preparation method has strong process reliability, high flexibility, and high production efficiency. It can be used to prepare large-area perovskite cells without hole transport layers, and the consistency of the prepared perovskite cells is high. It should be noted that the preparation method provided in the embodiment of the present application can also prepare small-area perovskite cells without hole transport layers. The present application has no restrictions on the area of ​​the perovskite cells to be prepared. In some embodiments of the present application, the area of ​​the conductive substrate in the first direction is ≥10 4 mm 2 , the first direction is perpendicular to the stacking direction of the conductive substrate and the perovskite crystal layer. In some specific embodiments, in the first direction, the size of the conductive substrate can be, for example, 100 mm×100 mm, 300 mm×300 mm, 300 mm×400 mm, 1.2 m×0.6 m, or 2.4 m×1.2 m.

[0057] In some embodiments of the present application, step S14 is also included: an electron transport layer, an interface barrier layer and an electrode are sequentially stacked on the surface of the perovskite crystal layer facing away from the transparent conductive substrate. In the embodiment of the present application, the preparation process of the electron transport layer, the interface barrier layer and the electrode can select the process and parameters familiar to ordinary technicians in the field, and the present application does not limit this. In the embodiment of the present application, P2 scribing of the preform provided with the electron transport layer and P3 scribing of the electrode are also included to obtain a perovskite battery with a series or parallel structure.

[0058] In some embodiments of the present application, in step S11-step S13, the parameters involved can refer to the parameters involved in the preparation method of the perovskite crystal film in the above text, for example: in some embodiments, in step S11, the content of the SAMs hole transport material in the perovskite precursor solution is 0.01mg / L-10mg / L. Specifically, the content of the SAMs hole transport material in the perovskite precursor solution can be, for example, 0.01mg / L, 0.02mg / L, 0.05mg / L, 0.1mg / L, 0.5mg / L, 0.8mg / L, 1mg / L, 2mg / L, 3mg / L, 4mg / L, 5mg / L, 6mg / L, 7mg / L, 8mg / L, 9mg / L, 10mg / L, etc.

[0059] In some embodiments of the present application, in step S11, before the perovskite precursor solution is set on the surface of the conductive substrate, the conductive substrate is also cleaned, and the surface of the conductive substrate is treated with ozone plasma after cleaning. In the embodiment of the present application, the above-mentioned cleaning can be a process and parameters familiar to technicians in the field, for example, ultrasonic cleaning is performed with isopropanol, acetone, deionized water, and ethanol in sequence, drying, and then ozone plasma treatment. In a specific embodiment on one side, considering the actual application requirements, the conductive substrate is also subjected to P1 scribing treatment before cleaning to divide the conductive substrate into several sub-areas.

[0060] Since the preparation method used in the embodiment of the present application does not require the use of additional steps (such as anti-solvent extraction and other processes), in some embodiments of the present application, in step S11, the perovskite precursor solution is set on the surface of one side of the conductive substrate in an air atmosphere. In this way, the process requirements for the equipment are low, which is also conducive to reducing production costs.

[0061] In the embodiment of the present application, in step S11, arranging the perovskite precursor solution on the conductive substrate includes: coating the perovskite precursor solution on the transparent conductive substrate. The coating can be any process known to technicians in the field. Considering that a large-area perovskite cell needs to be prepared in some cases, the coating process includes but is not limited to scraping, slit coating, etc.

[0062] In some embodiments of the present application, in step S11, the vacuum degree of the vacuum environment is 5Pa-0.1MPa. In some specific embodiments, the vacuum degree of the vacuum environment is 5Pa-50 Pa. The appropriate vacuum degree is conducive to the rapid deposition of the SAMs hole transport material in the perovskite coating to the side of the perovskite crystal layer precursor close to the transparent conductive substrate, and the crystallization rate of the perovskite material and the volatilization rate of the solvent are controlled within a suitable range, which is conducive to improving the crystal quality of the perovskite mesophase, and optimizing the interface contact between the final light absorption layer and the transparent conductive substrate, and improving the photoelectric conversion efficiency of the final perovskite cell. Specifically, the vacuum degree of the vacuum environment can be, for example, 5Pa, 10Pa, 20Pa, 50Pa, 100Pa, 200Pa, 300Pa, 400Pa, 500Pa, 600Pa, 700Pa, 800Pa, 900Pa, 0.1MPa, etc.

[0063] In some implementations of the present application, in step S11, the first preform may be placed in the cavity, and then evacuated to a vacuum degree of 5Pa-0.1MPa at a vacuum rate of 0.1L / s-10L / s.

[0064] In some embodiments of the present application, the first time length is ≥ 1 min. In some specific embodiments, the first time length is also controlled to be ≤ 20 min. Therefore, in some specific embodiments, the first time length is 1 min-20 min.

[0065] In some specific embodiments of the present application, in step S11, the first preform is placed in a vacuum environment of 5Pa-0.1MPa for 1min-20min.

[0066] In the embodiment of the present application, the material of the conductive substrate can be any conductive material known in the art that is suitable for perovskite cells, for example, including but not limited to one or more of indium tin oxide, tin fluoride oxide, aluminum-doped zinc oxide and germanium oxide.

[0067] In the embodiment of the present application, the perovskite material can be any of the aforementioned perovskite materials known in the art that are suitable for the light absorption layer of the perovskite cell. In the embodiment of the present application, the SAMs hole transport material can be the aforementioned SAMs hole transport material known in the art that is suitable for the perovskite cell. In the embodiment of the present application, in step S13, the annealing treatment can be a process and parameters well known to technicians in the field, and the present application does not limit this.

[0068] See also Figure 3The embodiment of the present application further provides a perovskite battery, comprising a conductive substrate 10 and a perovskite crystal layer 20 arranged in a stacked manner, wherein the perovskite crystal layer 20 comprises a first sublayer 201 and a second sublayer 202 arranged in a stacked manner, wherein the second sublayer 202 is arranged close to the conductive substrate 10, and the second sublayer 202 comprises perovskite crystals and a self-assembled single-molecule hole transport material dispersed between the perovskite crystals;

[0069] The area of ​​the perovskite cell in the second direction is ≥10 4 mm 2 The second direction is perpendicular to the stacking direction of the conductive substrate 10 and the perovskite crystal layer 20 .

[0070] The perovskite cell provided in the embodiment of the present application has no hole transport layer, but because the self-assembled single-molecule hole transport material is dispersed in the second sublayer, it can play a role in hole transport when the perovskite cell is working, ensuring the performance of the perovskite cell, with high consistency and high photoelectric conversion efficiency. In addition, since there is no hole transport layer, the preparation cost of the perovskite cell provided in the embodiment of the present application is low, and compared with the perovskite cell containing a hole transport layer in the related art, when achieving a comparable photoelectric conversion efficiency, the perovskite cell provided in the embodiment of the present application is thinner. More importantly, the embodiment of the present application provides for the first time a large area (≥10 4 mm 2 )'s hole-transport-layer-free perovskite cell can be commercially applied.

[0071] In some embodiments of the present application, the perovskite crystal layer is square; in the second direction, the size of the perovskite crystal layer can be, for example, 100mm×100mm, 300mm×300mm, 300mm×400mm, 1.2m×0.6m, or 2.4m×1.2m.

[0072] In some embodiments of the present application, the first sublayer does not contain SAMs hole transport material. Considering that in some cases, the SAMs hole transport material may not be completely deposited in the second sublayer, in other embodiments, the first sublayer also contains a very small amount of SAMs hole transport material, specifically, the mass content of the SAMs hole transport material in the first sublayer is <0.1%, for example, 0.01%.

[0073] In some embodiments of the present application, the thickness of the second sublayer is 10nm-30nm. In the embodiment of the present application, a step meter, a scanning electron microscope, an ellipsometer, etc. can be used to characterize the thickness of the second sublayer. Controlling the thickness of the second sublayer within the above range can make the final perovskite battery have a better hole transport ability, which is conducive to its performance, and the total thickness of the perovskite can be controlled within a suitable range, thereby improving the thinness of the perovskite battery. Specifically, the thickness of the second sublayer can be, for example, 10nm, 12nm, 15nm, 18nm, 20nm, 22nm, 25nm, 28nm, 30nm.

[0074] In some embodiments of the present application, the mass content of the SAMs hole transport material in the second sublayer is 0.1%-1%. In the embodiment of the present application, X-ray photoelectron spectroscopy (XPS) can be used to characterize the mass content of the SAMs hole transport material in the second sublayer. In this way, the concentration of the SAMs hole transport material in the second sublayer is more appropriate, firstly, it is conducive to ensuring that the hole transport capacity of the second sublayer is high, and secondly, considering that in some cases SAMs are dispersed between the perovskite materials before the perovskite materials crystallize, so that the crystallization quality of the perovskite crystals is better, thereby ensuring that the photoelectric conversion efficiency of the final perovskite cell is high.

[0075] In addition, considering that the content of SAMs hole transport materials decreases rapidly from the first sublayer to the second sublayer, the presence of the first sublayer and the second sublayer can also be characterized by characterizing the distribution intensity of the SAMs hole transport materials in the first sublayer and the second sublayer in the perovskite crystal layer by time of flight secondary ion mass spectrometry (TOF-SIMS).

[0076] In some embodiments of the present application, the thickness of the perovskite crystal layer is 400nm-600nm. Specifically, the thickness of the perovskite crystal layer can be, for example, 400nm, 420nm, 450nm, 480nm, 500nm, 520nm, 550nm, 580nm, 600nm, etc.

[0077] In some embodiments of the present application, the perovskite battery further includes a stacked electron transport layer and an electrode, and the electron transport layer is arranged near the surface of the side of the perovskite crystal layer away from the conductive substrate. In the embodiment of the present application, the above-mentioned electrode serves as the cathode of the perovskite battery. In the embodiment of the present application, the materials of the above-mentioned electron transport layer and the electrode can be any known material suitable for the electron transport layer and the cathode material of the PIN perovskite battery by technicians in the field. Specifically, the materials of the above-mentioned electron transport layer include but are not limited to (6,6)-phenyl C61 butyric acid methyl ester (PCBM), fullerene C60, SnO2, TiO2, etc. The materials of the electrode include but are not limited to gold, silver, copper, aluminum and conductive carbon, etc.

[0078] In some specific embodiments, an interface barrier layer is further provided between the electron transport layer and the electrode. Figure 4 The perovskite cell includes a conductive substrate 10, a perovskite crystal layer 20, an electron transport layer 30, an interface barrier layer 40 and an electrode 50 stacked in sequence. In the embodiment of the present application, the material of the interface barrier layer can be any material known to technicians in the field, such as 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (BCP Chinese alias: bathocuproin), tin dioxide (SnO2), polyethyleneimine (PEI), etc.

[0079] The embodiment of the present application also provides a photovoltaic system, including an electrically connected photovoltaic module and an energy storage system, wherein the photovoltaic module includes the perovskite battery provided in the embodiment of the present application, or includes the perovskite battery prepared by the preparation method of the perovskite battery provided in the embodiment of the present application. Due to the perovskite battery provided in the embodiment of the present application, the above photovoltaic system has strong market competitiveness.

[0080] The technical solution of the present application is further illustrated by multiple embodiments below.

[0081] Example 1

[0082] (1) The transparent conductive substrate (specifically ITO glass) was divided into 10 sub-regions of equal area by laser scribing (P1 scribing, dividing the ITO region), each sub-region was 8 mm wide. It was ultrasonically cleaned with isopropyl alcohol, acetone, deionized water, and ethanol for 20 minutes in sequence, and then dried and treated with plasma for 500 seconds;

[0083] (2) Dissolve the SAMs hole transport material (specifically Meo-2PACZ) in a solvent (specifically 2-ME), and then add it to the solution of the perovskite material to obtain a perovskite precursor solution. The concentration of the SAMs hole transport material in the perovskite precursor solution is 0.5 mg / mL. The perovskite material solution is a mixture of FAI, CsI, MABr, PbBr2, and PbI2 dissolved in DMF and NMP with a volume ratio of 6:1, specifically 1.2 mol / L Cs 0.1 MA 0.05 FA 0.85 PbI 0.95 Br 0.5 .

[0084] (3) Please refer to Figure 2 The perovskite precursor solution is deposited on the surface of the ITO glass substrate in air by using a blade coating method. Specifically, the blade height is 200 μm and the blade speed is 25 mm / s to obtain a first preform.

[0085] (4) The first preform is placed in a vacuum environment with a vacuum degree of 10 Pa and allowed to stand for 2 minutes to obtain a second preform.

[0086] (5) The obtained second preform was annealed at 150°C for 10 min, and then transferred to a vacuum plating chamber, and a 30 nm thick C60 was deposited as an electron transport layer and a 6 nm thick BCP was deposited as an interface barrier layer by thermal evaporation; the sample after the transport layer and the interface layer were evaporated was subjected to P2 scribing (P2 scribing removes the material of the perovskite crystal layer in a specific area); then, a 120 nm thick silver electrode was evaporated by vacuum thermal evaporation, and 10 sub-cells were connected in series by laser scribing P3 (scribing the silver electrode) to obtain a perovskite cell. For specific P1, P2, and P3 scribing, please refer to Figure 5 , please see the picture of the prepared perovskite battery Figure 6 .

[0087] Example 2

[0088] The only difference from Example 1 is that the first preform is placed in a vacuum environment with a vacuum degree of 50 Pa and left to stand for 2 minutes to obtain a second preform.

[0089] Example 3

[0090] The only difference from Example 1 is that the first preform is placed in a vacuum environment with a vacuum degree of 100 Pa and left to stand for 2 minutes to obtain a second preform.

[0091] In order to highlight the beneficial effects of the embodiments of the present application, the following comparative examples are provided.

[0092] Comparative Example 1

[0093] (1) The transparent conductive substrate (specifically ITO glass) was divided into 10 sub-regions of equal area by laser scribing (P1 scribing, dividing the ITO region), each sub-region was 8 mm wide. It was ultrasonically cleaned with isopropyl alcohol, acetone, deionized water, and ethanol for 20 minutes in sequence, and then dried and treated with plasma for 500 seconds;

[0094] (2) The solution of the perovskite material is deposited on the surface of the ITO glass substrate by a doctor blade method, specifically, the blade height is 200 μm, the blade speed is 25 mm / s, and a first preform is obtained. The solution of the perovskite material is a mixture of FAI, CsI, MABr, PbBr2, and PbI2 dissolved in DMF and NMP with a volume ratio of 6:1, specifically 1.2 mol / L Cs 0.1 MA 0.05 FA 0.85 PbI 0.95 Br 0.5 .

[0095] (3) The first preform is placed in a vacuum environment with a vacuum degree of 10 Pa and allowed to stand for 2 minutes to obtain a second preform.

[0096] (4) The obtained second preform was annealed at 150°C for 10 min, and then transferred to a vacuum coating chamber, and a 30 nm thick C60 was deposited as an electron transport layer and a 6 nm thick BCP was deposited as an interface barrier layer by thermal evaporation; the sample after the transport layer and the interface layer were evaporated was subjected to P2 scribing (P2 scribing removed the material of the perovskite crystal layer in a specific area); then, a 120 nm thick silver electrode was evaporated by vacuum thermal evaporation, and 10 sub-cells were connected in series by laser scribing P3 (scribing the silver electrode) to obtain a perovskite cell.

[0097] Comparative Example 2

[0098] The difference from Example 1 lies in step (2) and step (3), specifically:

[0099] (1) The transparent conductive substrate (specifically ITO glass) was divided into 10 sub-regions of equal area by laser scribing (P1 scribing, dividing the ITO region), each sub-region was 8 mm wide. It was ultrasonically cleaned with isopropyl alcohol, acetone, deionized water, and ethanol for 20 minutes in sequence, and then dried and treated with plasma for 500 seconds;

[0100] (2) The SAMs hole transport material (specifically Meo-2PACZ) was dissolved in isopropanol to make the concentration of Meo-2PACZ 1 mg / mL, and then coated on the surface of the ITO glass substrate and annealed at 105° C. for 15 min.

[0101] (3) Then, a solution of the perovskite material is coated on the surface of the ITO substrate with the coating layer on the back, with a blade height of 200 μm and a blade speed of 25 mm / s to obtain a first preform. The solution of the perovskite material is a mixture of FAI, CsI, MABr, PbBr2, and PbI2 dissolved in DMF and NMP with a volume ratio of 6:1. The specific amount of the perovskite material is 1.2 mol / L Cs 0.1 MA 0.05 FA 0.85 PbI 0.95 Br 0.5 .

[0102] (4) The first preform is placed in a vacuum environment with a vacuum degree of 10 Pa and allowed to stand for 2 minutes to obtain a second preform.

[0103] (5) The obtained second preform was annealed at 150°C for 10 min, and then transferred to a vacuum coating chamber, and a 30 nm thick C60 was deposited as an electron transport layer and a 6 nm thick BCP was deposited as an interface barrier layer by thermal evaporation; the sample after the transport layer and the interface layer were evaporated was subjected to P2 scribing (P2 scribing removed the material of the perovskite crystal layer in a specific area); then, a 120 nm thick silver electrode was evaporated by vacuum thermal evaporation, and 10 sub-cells were connected in series by laser scribing P3 (scribing the silver electrode) to obtain a perovskite cell.

[0104] The solar cells prepared in the above embodiments and comparative examples were tested using an IV tester. The illumination area of ​​the solar cells in the embodiments and comparative examples was 60 cm 2 , its current-voltage curve can be found in Figure 7 The open circuit voltage, short circuit current, fill factor and photoelectric conversion efficiency of the perovskite cells of each embodiment and comparative example are summarized in Table 1. For details, please refer to T_ZZB 1389-2019.

[0105] Table 1

[0106] Case Open circuit voltage / V Short circuit current / mA Fill factor / % efficiency / % Example 1 10.67 142.11 73.34 18.15 Example 2 10.02 128.16 66.47 15.13 Example 3 8.20 82.99 46.75 8.29 Comparative Example 1 6.10 82.68 37.70 3.40 Comparative Example 2 10.02 107.78 56.76 12.98

[0107] From the data in Table 1, it can be found that the preparation method provided in the embodiment of the present application can produce a large-area PIN perovskite battery without a hole transport layer, and by comparing the data of Example 1 and Comparative Example 2, it can be found that even if the same materials are used, if the perovskite material and the self-assembled single-molecule hole transport material are respectively coated on the surface of the substrate and left to stand under the same vacuum degree, the performance of the perovskite battery prepared in Example 1 is significantly better, indicating that the preparation method of the perovskite battery provided in the embodiment of the present application is more conducive to improving the uniformity of the perovskite crystal layer and thus improving the device performance.

[0108] The above is an exemplary embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made thereto without departing from the principles of the present application. These improvements and modifications are also considered to be within the scope of protection of the present application.

Claims

1. A method for preparing a perovskite crystal film, characterized in that: include: A perovskite precursor solution is placed on the surface of the substrate and allowed to stand in a vacuum environment, and then an annealing treatment is performed to obtain a perovskite crystal film on the surface of the substrate; Wherein, the perovskite precursor solution includes a perovskite material and a self-assembled single-molecule hole transport material.

2. The method for preparing a perovskite crystal thin film according to claim 1, characterized in that: The vacuum degree of the vacuum environment is 5Pa-0.1MPa, and the standing time is 1min-20min.

3. The method for preparing a perovskite crystal thin film according to claim 1 or 2, characterized in that: The step of arranging the perovskite precursor solution on the substrate comprises: coating the perovskite precursor solution on the surface of the substrate, wherein the coating process comprises at least one of blade coating and slit coating.

4. The method for preparing a perovskite crystal thin film according to any one of claims 1 to 3, characterized in that: The content of the self-assembled single molecule hole transport material in the perovskite precursor solution is 0.01 mg / L-10 mg / L.

5. The method for preparing a perovskite crystal thin film according to any one of claims 1 to 4, characterized in that: The perovskite material includes ABX3, A includes CH 3 NH 3+ HC(NH 2 ) 2+ , Cs + and Rb + One or more of, B includes Pb 2+ and / or Sn 2+ , X includes a halogen anion; The self-assembled monomolecular hole transport material includes (2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl)phosphonic acid, (2-(4-(di(4-methoxy)amino)phenyl)-1-cyanoethylene)phosphonic acid, (4-(2,7-dibromo-9,9-dimethylacridin-10(9H)-yl)butyl)phosphonic acid, (2-(9H-carbazole-9-yl)ethyl)phosphonic acid, (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid. Phosphonic acid, (2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl)phosphonic acid, (4-(3,6-dibromo-9H-carbazole-9-yl)butyl)phosphonic acid, (2-(3,6-dibromo-9H-carbazole-9-yl)ethyl)phosphonic acid, triphenylphosphinothioic acid 2-fluorobenzoic acid, (4-(7H-dibenzo[c,g]carbazole-7-yl)butylphosphonic acid and (4-((7H)-dibenzocarbazole-7-yl)ethyl)phosphonic acid.

6. A method for preparing a perovskite battery, characterized in that: include: A perovskite precursor solution is placed on the surface of a conductive substrate and allowed to stand in a vacuum environment, and then an annealing treatment is performed to form a perovskite crystal layer on the surface of the conductive substrate to obtain a perovskite battery; Wherein, the perovskite precursor solution includes a perovskite material and a self-assembled single-molecule hole transport material.

7. The method for preparing a perovskite battery according to claim 6, characterized in that: The area of ​​the conductive substrate in the first direction is ≥10 4 mm 2 , the first direction is perpendicular to the stacking direction of the conductive substrate and the perovskite crystal layer.

8. The method for preparing a perovskite battery according to claim 6 or 7, characterized in that: After forming the perovskite crystal layer, the method further comprises: An electron transport layer, an interface barrier layer and an electrode are sequentially stacked on a surface of the perovskite crystal layer away from the conductive substrate.

9. A perovskite battery, characterized in that: It includes a conductive substrate and a perovskite crystal layer arranged in layers, wherein the perovskite crystal layer includes a first sublayer and a second sublayer arranged in layers, the second sublayer is arranged close to the conductive substrate, and the second sublayer includes perovskite crystals and a self-assembled single-molecule hole transport material dispersed between the perovskite crystals; In the stacking direction perpendicular to the conductive substrate and the perovskite crystal layer, the area of ​​the perovskite cell is ≥10 4 2 mm.

10. The perovskite battery according to claim 9, characterized in that: The first sublayer is a perovskite crystal layer, or the first sublayer includes the perovskite crystal and the self-assembled monomolecular hole transport material, and the mass content of the self-assembled monomolecular hole transport material in the first sublayer is less than 0.1%.

11. The perovskite battery according to claim 9 or 10, characterized in that: The thickness of the second sub-layer is 10-30 nm; the mass content of the self-assembled monomolecular hole transport material in the second sub-layer is 0.1%-1%.

12. The perovskite battery according to any one of claims 9 to 11, characterized in that: The thickness of the perovskite crystal layer is 400nm-600nm.

13. The perovskite battery according to any one of claims 9 to 12, characterized in that: The perovskite cell further comprises an electron transport layer, an interface transport layer and an electrode which are stacked, and the electron transport layer is arranged close to a surface of the perovskite layer which is away from the transparent conductive substrate.

14. A photovoltaic system, characterized in that: Comprising an electrically connected photovoltaic component and an energy storage system, the photovoltaic component comprising a perovskite battery prepared by the method for preparing a perovskite battery according to any one of claims 6 to 8, or comprising a perovskite battery according to any one of claims 9 to 13.

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