Perovskite cell, preparation method thereof and photovoltaic module

Abstract

The invention discloses a perovskite cell, a preparation method thereof and a photovoltaic module, and relates to the field of photovoltaic technology. The perovskite cell comprises a transparent conductive layer, a photoelectric conversion layer and an electrode layer which are stacked in sequence. The photoelectric conversion layer comprises a hole transport layer, a perovskite layer, an inorganic passivation layer and an electron transport layer which are stacked in sequence. Wherein the D50 particle size of crystal grains of the perovskite layer is 0.73 [mu] m to 1.65 [mu] m. According to the perovskite cell, the inorganic passivation layer is inserted into the perovskite layer, so that the grain size of the perovskite layer can be improved, charge traps and recombination centers can be reduced, and the service life of current carriers can be prolonged, thereby passivating interface defects and improving the photoelectric conversion efficiency and stability of the perovskite cell.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic technology, and more specifically, to a perovskite solar cell, a preparation method thereof, and a photovoltaic module. Background Art

[0002] With the development of photovoltaic technology, the energy conversion efficiency of perovskite solar cells has been increased to 26.7%, making them a competitive type of solar cell. However, due to the high sensitivity of perovskite to moisture and oxygen in the air, most high-quality perovskite thin films are prepared in a strictly controlled inert environment, which can only be achieved by using complex air or humidity control systems. Inevitably, this increases the cost of manufacturing equipment and is not conducive to large-scale production. Therefore, studying the preparation process of perovskite photovoltaic devices in air has important academic and application values. However, interface defects are an important factor affecting the performance of perovskite solar cells. These defects may become recombination centers for carriers, reducing the efficiency and stability of the solar cells. The existing processes have poor improvement effects on the interface defects of perovskite materials, and the stability and efficiency of solar cells still need to be improved. Summary of the Invention

[0003] The objectives of the present application include providing a perovskite solar cell, a preparation method thereof, and a photovoltaic module, which can improve the interface quality of the perovskite layer and enhance the stability and photoelectric efficiency of the perovskite solar cell.

[0004] Embodiments of the present application may be implemented as follows:

[0005] In a first aspect, the present application provides a perovskite solar cell, including a transparent conductive layer, a photo-electric conversion layer, and an electrode layer that are sequentially stacked. The photo-electric conversion layer includes a hole transport layer, a perovskite layer, an inorganic passivation layer, and an electron transport layer that are sequentially stacked; wherein, the D50 particle size of the grains of the perovskite layer is 0.73 μm to 1.65 μm.

[0006] In an alternative embodiment, the D50 particle size of the grains of the perovskite layer is 1.49 μm to 1.65 μm.

[0007] In an alternative embodiment, the material of the inorganic passivation layer is lead borate or doped lead borate.

[0008] In an alternative embodiment, when the material of the inorganic passivation layer is doped lead borate, the material of the inorganic passivation layer is selected from at least one of lead borate doped with PbI2, lead borate doped with PbBr2, lead borate doped with PbCl2, and lead borate doped with Pb(SCN)2.

[0009] In an alternative embodiment, the doping ratio in the inorganic passivation layer is 1:1 to 10.

[0010] In an alternative embodiment, the thickness of the inorganic passivation layer is 1 nm to 8 nm.

[0011] In an alternative embodiment, the material of the transparent conductive layer is ITO, FTO or ZTO; or,

[0012] the material of the hole transport layer is selected from at least one of PTAA, 2PACZ, NiO x and 4PADBC.

[0013] In an alternative embodiment, the hole transport layer is attached to the transparent conductive layer, and the electron transport layer is attached to the electrode layer;

[0014] or, the electron transport layer is attached to the transparent conductive layer, and the hole transport layer is attached to the electrode layer.

[0015] In a second aspect, the present application provides a method for preparing a perovskite battery according to any one of the foregoing embodiments, including:

[0016] Obtaining a transparent conductive layer;

[0017] Fabricating a photoactive conversion layer on the transparent conductive layer, the photoactive conversion layer including a hole transport layer, a perovskite layer, an inorganic passivation layer, and an electron transport layer which are sequentially stacked, and the material of the inorganic passivation layer is lead borate or doped lead borate;

[0018] Fabricating an electrode layer on the photoactive conversion layer.

[0019] In an alternative embodiment, the step of fabricating the photoactive conversion layer on the transparent conductive layer includes:

[0020] Fabricating a hole transport layer on the transparent conductive layer;

[0021] Fabricating a perovskite layer on the hole transport layer;

[0022] Coating a slurry containing lead borate or doped lead borate on the perovskite layer and annealing to obtain an inorganic passivation layer;

[0023] Fabricating an electron transport layer on the inorganic passivation layer.

[0024] In an alternative embodiment, in the step of fabricating the inorganic passivation layer, the annealing temperature is 100 °C to 135 °C, and the annealing duration is 5 min to 10 min.

[0025] In an alternative embodiment, the step of fabricating the perovskite layer on the hole transport layer includes:

[0026] Coating a solution containing a PbI2 precursor on the hole transport layer and annealing to obtain a PbI2 thin film;

[0027] A solution containing an organic ammonium salt is coated on the PbI2 film and annealed to obtain a perovskite layer.

[0028] In an alternative embodiment, the step of obtaining the transparent conductive layer includes:

[0029] Ultrasonically cleaning the transparent conductive layer;

[0030] Subjecting the transparent conductive layer to ultraviolet ozone treatment.

[0031] In a third aspect, the present application provides a photovoltaic module, including the perovskite cell of any one of the embodiments in the first aspect, or including the perovskite cell prepared by the preparation method of the perovskite cell of any one of the foregoing second aspects.

[0032] The beneficial effects of the perovskite cell, its preparation method, and the photovoltaic module provided by the embodiments of the present application include:

[0033] The perovskite cell provided by the embodiments of the present application includes a transparent conductive layer, a photoelectric conversion layer, and an electrode layer that are sequentially stacked. The photoelectric conversion layer includes a hole transport layer, a perovskite layer, an inorganic passivation layer, and an electron transport layer that are sequentially stacked; wherein, the D50 particle size of the grains of the perovskite layer is 0.73 μm to 1.65 μm. In the embodiments of the present application, by adding an inorganic passivation layer between the electron transport layer and the perovskite layer, the grains of the perovskite layer can be made larger, and the D50 particle size reaches 0.73 μm to 1.65 μm. This can reduce the number of grain boundaries at the interface, reduce charge traps and recombination centers, increase the carrier lifetime, thereby passivating the interface defects, and improving the photoelectric conversion efficiency and stability of the perovskite cell. Further, the inorganic passivation layer contains lead borate, which has ionized anchoring groups and excellent Lewis base properties, can effectively neutralize the local charges near the interface defects of the perovskite layer, exhibits enhanced passivation ability to the defect energy levels, and alleviates the problem of interface recombination. Lead borate has good chemical stability and thermal stability, can enhance the durability of the interface, and its suitable energy level arrangement is beneficial to the extraction and transport of charges, thereby improving the conversion efficiency of the battery. Further, a dopant is introduced into the inorganic passivation layer, making the grains of the perovskite layer further larger, better reducing the cracks at the grain boundaries, further reducing the interface defects, and improving the passivation effect of the inorganic passivation layer. In addition, the introduction process of lead borate is simple, is easily compatible with the existing perovskite cell preparation process, and is conducive to large-scale production.

[0034] The preparation method of the perovskite cell provided by the embodiments of the present application can be used to prepare the above-mentioned perovskite cell. The photovoltaic module provided by the embodiments of the present application includes the above-mentioned perovskite cell or includes the solar cell prepared by the above-mentioned preparation method. Therefore, the photovoltaic module has better photoelectric conversion efficiency and reliability. Description of the Drawings

[0035] To more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for the embodiments will be briefly introduced below. It should be understood that the following accompanying drawings only show some embodiments of the present application, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related accompanying drawings can also be obtained based on these drawings.

[0036] Figure 1 Schematic diagram of a perovskite solar cell in an embodiment of the present application;

[0037] Figure 2 Flowchart of the preparation method of a perovskite solar cell in an embodiment of the present application;

[0038] Figure 3 J-V curve diagram of the perovskite solar cells prepared in Examples 1-5 and Comparative Example 1 of the present application;

[0039] Figure 4 Scanning electron microscope (SEM) image of the perovskite layer after setting an inorganic passivation layer in Example 1 of the present application;

[0040] Figure 5 Scanning electron microscope (SEM) image of the perovskite layer after setting an inorganic passivation layer in Example 2 of the present application;

[0041] Figure 6 Scanning electron microscope (SEM) image of the perovskite layer in Comparative Example 1;

[0042] Figure 7 Stability test diagram of the perovskite solar cells prepared in Examples 1-2 and Comparative Example 1 of the present application.

[0043] Icon: 100 - transparent conductive layer; 200 - hole transport layer; 300 - perovskite layer; 400 - inorganic passivation layer; 500 - electron transport layer; 600 - electrode layer. Detailed implementation manners

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Usually, the components of the embodiments of the present application described and shown in the accompanying drawings here can be arranged and designed in various different configurations.

[0045] Accordingly, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but merely represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts fall within the scope of protection of the present application.

[0046] It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not require further definition and explanation in subsequent drawings.

[0047] In the description of the present application, it should be noted that if terms such as "upper", "lower", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is customarily placed during use, it is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0048] In addition, terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0049] It should be noted that the features in the embodiments of the present application can be combined with each other without conflict.

[0050] Due to excessive defects existing at the interface of the perovskite material in perovskite solar cells and poor carrier transport, in order to overcome these bottlenecks, interface engineering has become a key method to improve the energy conversion efficiency of perovskite solar cells. Interface engineering is a technical method that aims to reduce interface defects, improve electron transport, and enhance interface bonding force by regulating the surface properties of materials and interface interactions, thereby improving the performance and stability of optoelectronic devices. However, in the existing processes for improving the interface quality of perovskite materials, either the process is complex and the cost is high, or the interface passivation effect is limited, making it difficult to effectively improve the photoelectric conversion efficiency and stability of perovskite solar cells.

[0051] To this end, the embodiments of the present application provide a perovskite solar cell and a preparation method thereof. By adding an inorganic passivation layer between the perovskite layer and the electron transport layer, the side of the perovskite layer adjacent to the inorganic passivation layer has a larger grain size, thereby effectively reducing the cracks at the grain boundaries, reducing the defects at the interface of the perovskite layer, improving the carrier transport ability, and enhancing the bonding force of the interface. And this perovskite solar cell is easy to prepare and has a low process cost.

[0052] Figure 1 It is a schematic diagram of a perovskite solar cell in an embodiment of the present application. As Figure 1As shown, the perovskite solar cell provided by the embodiment of the present application includes a transparent conductive layer 100, a photo - electric conversion layer, and an electrode layer 600 that are stacked in sequence. The photo - electric conversion layer includes a hole - transporting layer 200, a perovskite layer 300, an inorganic passivation layer 400, and an electron - transporting layer 500 that are stacked in sequence; wherein, the D50 particle size of the grains of the perovskite layer 300 is 0.73 μm to 1.65 μm. It can be understood that the passivation effect of the inorganic passivation layer 400 on the perovskite layer 300 makes the grain size of the perovskite layer 300 larger. Therefore, the grain - boundary cracks and defects presented on the interface are reduced, and the interface recombination problem can be better alleviated. Further, the D50 particle size of the grains of the perovskite layer 300 is 1.49 μm to 1.65 μm.

[0053] In this embodiment, the perovskite solar cell is a reverse - type perovskite solar cell. As Figure 1 shown, its hole - transporting layer 200 is in contact with the transparent conductive layer 100, and the electron - transporting layer 500 is in contact with the electrode layer 600. In other alternative embodiments, the perovskite solar cell can also be a normal - type perovskite solar cell, that is, the electron - transporting layer 500 can be in contact with the transparent conductive layer 100, and the hole - transporting layer 200 can be in contact with the electrode layer 600. It should be understood that Figure 1 only the distribution of each layer structure in the perovskite solar cell is schematically shown, and it does not represent the true thickness ratio of each film layer.

[0054] Optionally, the material of the inorganic passivation layer 400 is lead borate or doped lead borate. Lead borate has good chemical stability and thermal stability, can enhance the durability of the interface, and its suitable energy - level arrangement is beneficial to the extraction and transport of charges, thereby improving the conversion efficiency of the solar cell. In the perovskite solar cell of the present application, an inorganic passivation layer 400 containing lead borate is added between the perovskite layer 300 and the electron - transporting layer 500. It has ionized anchoring groups and superior Lewis base properties, can effectively neutralize the local charges near the interface defects of the perovskite layer 300, shows enhanced passivation ability for the defect energy levels, and alleviates the problem of interface recombination. Inserting an inorganic passivation layer 400 on the perovskite layer 300 can reduce charge traps and recombination centers, increase the carrier lifetime, thereby passivating the interface defects and improving the photo - electric conversion efficiency and stability of the perovskite solar cell. When the material of the inorganic passivation layer 400 is lead borate, the D50 particle size of the grains of the perovskite layer 300 can reach 0.73 μm to 1.65 μm. Further, introducing a dopant into the inorganic passivation layer 400 makes it easier for the particles at the grain boundaries to become larger, better reduces the cracks at the grain boundaries, further reduces the interface defects, and improves the passivation effect of the inorganic passivation layer 400. When the material of the inorganic passivation layer 400 is doped lead borate, the D50 particle size of the grains of the perovskite layer 300 can reach 1.49 μm to 1.65 μm.

[0055] Optionally, when the material of the inorganic passivation layer 400 is doped lead borate, it may specifically be selected from at least one of lead borate doped with PbI2, lead borate doped with PbBr2, lead borate doped with PbCl2, and lead borate doped with Pb(SCN)2. The doped halogen ions can chemically interact with the lead vacancies or other defect sites on the perovskite surface, thereby reducing interface defects and improving the passivation effect. When the material of the inorganic passivation layer 400 is lead borate doped with Pb(SCN)2, the D50 particle size of the grains of the perovskite layer 300 can reach more than 1.49 μm. Optionally, the doping ratio in the inorganic passivation layer 400 is 1:1 to 10.

[0056] Optionally, the material of the transparent conductive layer 100 is indium tin oxide (ITO), fluorine-doped tin oxide (FTO), or zinc tin oxide (ZTO). The material of the hole transport layer 200 is selected from at least one of poly(triarylamine) (PTAA), 2-phenyl-1H-imidazole-4,5-dicarboxylic acid (2PACZ), NiO x and at least one of 4-phenyl-4'-(9-carbazolyl)-diphenylcarbazole (4PADBC). The material of the perovskite layer 300 can be selected as FAPbI3. The material of the electron transport layer 500 can be an inorganic material, such as TiO, ZnO, SnO, WO, etc.; it can also be an organic material, such as PCBM, C60, ICBA, etc. The material of the electrode layer 600 is a metal, such as copper, nickel, molybdenum, or silver.

[0057] Optionally, the thickness of the inorganic passivation layer 400 is 1 nm to 8 nm; the thickness of the transparent conductive layer 100 is 80 nm to 120 nm; the thickness of the hole transport layer 200 is 10 to 30 nm; the thickness of the perovskite layer 300 is 550 nm to 650 nm; the thickness of the electron transport layer 500 is 20 nm to 30 nm; the thickness of the electrode layer 600 is 50 nm to 200 nm.

[0058] Figure 2 This is a flowchart of the preparation method of the perovskite battery in an embodiment of the present application. As Figure 2 shown, the preparation method of the perovskite battery provided by the embodiment of the present application can be used to prepare the perovskite battery provided by the above embodiment. The preparation method includes the following steps:

[0059] Step S100, obtain the transparent conductive layer 100.

[0060] In the embodiment of the present application, step S100 may specifically include:

[0061] Step S110, perform ultrasonic cleaning on the transparent conductive layer 100.

[0062] Optionally, the transparent conductive layer 100 is ultrasonically cleaned successively in a cleaning agent, ultrapure water, isopropyl alcohol, and dishwashing liquid for 30 min to 90 min.

[0063] Step S120: Perform ultraviolet ozone treatment on the transparent conductive layer 100.

[0064] Optionally, the ultraviolet ozone treatment lasts for 3 min to 30 min.

[0065] The above cleaning steps can remove contaminants, increase surface energy, reduce surface defects of the transparent conductive layer 100, and reduce recombination; the ultraviolet ozone treatment can further clean, increase surface hydrophilicity, improve the chemical state, and increase conductivity. Therefore, the performance and stability of the perovskite solar cell can be improved.

[0066] Step S200: Fabricate a photoactive conversion layer on the transparent conductive layer 100. The photoactive conversion layer includes a hole transport layer 200, a perovskite layer 300, an inorganic passivation layer 400, and an electron transport layer 500 that are sequentially stacked. The material of the inorganic passivation layer 400 is lead borate or doped lead borate.

[0067] To fabricate Figure 1 Taking the shown inverted perovskite solar cell as an example, step S200 may include the following steps:

[0068] Step S210: Fabricate a hole transport layer 200 on the transparent conductive layer 100.

[0069] Optionally, a raw material for fabricating the hole transport layer 200, such as at least one of PTAA, 2PACZ, NiO x , 4PADBC, is coated on the transparent conductive layer 100. The spin coating method can be used, with a rotation speed between 3000 rpm and 6000 rpm and a time of 10 s to 60 s. After spin coating is completed, it is placed on a hot plate at 90 °C to 120 °C for annealing treatment, and the annealing time is 5 min to 20 min.

[0070] Step S220: Fabricate a perovskite layer 300 on the hole transport layer 200.

[0071] Taking the fabrication of an FAPbI2 perovskite thin film as an example, optionally, the steps for fabricating the perovskite layer 300 include: coating a solution containing a PbI2 precursor on the hole transport layer 200 and performing annealing to obtain a PbI2 thin film; coating a solution containing an organic ammonium salt on the PbI2 thin film and performing annealing to obtain the perovskite layer 300.

[0072] Optionally, in the solution containing the PbI2 precursor, the concentration of the PbI2 precursor is 700 mg / ml to 800 mg / ml, and the solvent is a mixed organic solvent of N,N-dimethylformamide (DMF) and N-methylpyrrolidone (NMP); wherein, the volume ratio of DMF to NMP in the mixed organic solvent is 9:1 to 5. The solution containing the PbI2 precursor can be coated on the hole transport layer 200 by a spin coating process; the spin coating time is 3 s to 5 s, the subsequent annealing temperature is 50 °C to 70 °C, and the annealing time is 2 min to 10 min.

[0073] Optionally, the step of coating the solution containing the organic ammonium salt on the PbI2 thin film can be realized by a slot coating or spin coating process. Optionally, the organic ammonium salt components include FAI, MASCN, and NH4SCN, and the organic ammonium salt is mixed and dissolved in isopropanol. The concentrations of FAI, MASCN, and NH4SCN are 60 mg / ml to 100 mg / ml, 5 mg / ml to 20 mg / ml, and 3 mg / ml to 9 mg / ml, respectively. After the coating is completed, annealing is carried out at 120 °C to 150 °C in air for 20 min to 60 min. A FAPbI3 perovskite thin film, i.e., the perovskite layer 300, is formed.

[0074] Step S230, coating a slurry containing lead borate or doped lead borate on the perovskite layer 300 and performing annealing to obtain the inorganic passivation layer 400.

[0075] Optionally, the coating is carried out by spin coating or slot coating in air. After the coating is completed, annealing is carried out at 100 to 135 °C for 5 min to 10 min.

[0076] Step S240, fabricating an electron transport layer 500 on the inorganic passivation layer 400.

[0077] Optionally, the electron transport layer 500 is formed by spin coating or evaporation.

[0078] It should be understood that the above steps S210 to S240 are introduced by taking the fabrication of a p-i-n perovskite solar cell as an example. When fabricating a normal perovskite solar cell, the electron transport layer 500, the inorganic passivation layer 400, the perovskite layer 300, and the hole transport layer 200 should be fabricated in sequence.

[0079] Step S300, fabricating an electrode layer 600 on the photoactive layer.

[0080] Optionally, the electrode layer 600 is formed on the photoactive layer by evaporation or printing.

[0081] Hereinafter, the preparation method and beneficial effects of the perovskite solar cell provided by the present application will be specifically described in conjunction with Examples 1 to 6 and Comparative Example 1.

[0082] Example 1

[0083] This example provides a preparation method for a perovskite solar cell, and the specific steps are as follows:

[0084] 1) The transparent conductive layer 100 made of ITO is ultrasonically treated with ITO cleaning agent, ultrapure water, isopropanol and dishwashing liquid for 60 minutes in sequence. Then, the transparent conductive layer 100 is treated with ultraviolet ozone for 10 minutes.

[0085] 2) A hole transport layer 200 is prepared on the transparent conductive layer 100. PTAA is selected as the material for the hole transport layer 200, and the spin coating speed is 4000 rpm for 30 seconds. After spin coating is completed, it is placed on a hot plate at 100 °C for annealing treatment, and the annealing time is 10 minutes.

[0086] 3) The PbI2 thin film is prepared by spin coating. A PbI2 precursor solution with a concentration of 700 mg / ml is taken, and the volume ratio of DMF to NMP in the solvent is 9:1. The spin coating parameters are 3600 rpm for 3 seconds. After spin coating, it is soaked in isopropanol for 15 - 30 seconds, and then annealed at 60 °C for 2 minutes. Subsequently, the prepared organic ammonium salt mixture solution is spin coated, and the concentration ratio of FAI:MASCN:NH4SCN is 90:15:5. It is annealed in air at 135 °C for 60 minutes. The FAPbI3 perovskite thin film is formed, that is, the perovskite layer 300 is obtained.

[0087] 4) An inorganic passivation layer 400 is prepared on the perovskite layer 300 with lead borate as the material by spin coating, and the spin coating parameters are 4000 rpm. After spin coating, it is annealed at 135 °C for 5 minutes to obtain the inorganic passivation layer 400.

[0088] 5) An electron transport layer 500 is fabricated on the inorganic passivation layer 400, and finally an electrode layer 600 is deposited by evaporation to obtain the perovskite solar cell. The thickness of the electron transport layer 500 is 25 nm, and the thickness of the metal electrode is 100 nm.

[0089] Example 2

[0090] This example provides a preparation method for a perovskite solar cell, and the specific steps are as follows:

[0091] 1) The transparent conductive layer 100 made of ITO is ultrasonically treated with ITO cleaning agent, ultrapure water, isopropanol and dishwashing liquid for 60 minutes in sequence. Then, the transparent conductive layer 100 is treated with ultraviolet ozone for 10 minutes.

[0092] 2) Prepare a hole transport layer 200 on the transparent conductive layer 100. Select PTAA as the material for the hole transport layer 200, with a spin coating speed of 4000 rpm and a time of 30 seconds. After spin coating is completed, place it on a hot plate at 100 °C for annealing treatment, and the annealing time is 10 minutes.

[0093] 3) Prepare a PbI2 thin film by spin coating. Take a PbI2 precursor solution with a concentration of 700 mg / ml, and the volume ratio of DMF to NMP in the solvent is 9:1. The spin coating parameters are 3600 rpm and the time is 3 seconds. After spin coating, soak it in isopropanol for 15 - 30 seconds, and then anneal it at 60 °C for 2 minutes. Subsequently, spin coat the prepared organic ammonium salt mixture, and the concentration ratio of FAI:MASCN:NH4SCN is 90:15:5. Anneal it at 135 °C in air for 60 minutes. Form a FAPbI3 perovskite thin film, that is, obtain the perovskite layer 300.

[0094] 4) Use Pb(SCN)2 doped with lead borate (doping ratio of 1:5) as the material to prepare an inorganic passivation layer 400 on the perovskite layer 300 by spin coating, with spin coating parameters of 4000 rpm. After spin coating, perform annealing at 135 °C for 5 minutes to obtain the inorganic passivation layer 400.

[0095] 5) Fabricate an electron transport layer 500 on the inorganic passivation layer 400, and finally evaporate and deposit to form an electrode layer 600 to obtain a perovskite solar cell. The thickness of the electron transport layer 500 is 25 nm, and the thickness of the metal electrode is 100 nm.

[0096] Example 3

[0097] This example provides a method for preparing a perovskite solar cell, and the specific steps are as follows:

[0098] 1) Ultrasonically treat the transparent conductive layer 100 made of ITO with ITO cleaning agent, ultrapure water, isopropanol, and dishwashing liquid for 60 minutes. Then perform ultraviolet ozone treatment on the transparent conductive layer 100 for 10 minutes.

[0099] 2) Prepare a hole transport layer 200 on the transparent conductive layer 100. Select PTAA as the material for the hole transport layer 200, with a spin coating speed of 4000 rpm and a time of 30 seconds. After spin coating is completed, place it on a hot plate at 100 °C for annealing treatment, and the annealing time is 10 minutes.

[0100] 3) Prepare the PbI2 thin film by spin coating. Take a PbI2 precursor solution of 700 mg / ml, with the volume ratio of DMF to NMP in the solvent being 9:1, the spin coating parameters being 3600 rpm, and the time being 3 seconds. After spin coating, soak it in isopropanol for 15 - 30 seconds, and then perform annealing at 60 °C for 2 minutes. Subsequently, spin coat the prepared organic ammonium salt mixture, with the concentration ratio of FAI:MASCN:NH4SCN being 90:15:5. Perform annealing at 135 °C in air for 60 minutes. Form the FAPbI3 perovskite thin film, that is, obtain the perovskite layer 300.

[0101] 4) Use lead borate doped with PbCl2 (doping ratio 3:5) as the material to prepare the inorganic passivation layer 400 on the perovskite layer 300 by spin coating, with the spin coating parameters being 4000 rpm. After spin coating, perform annealing at 135 °C for 5 minutes to obtain the inorganic passivation layer 400.

[0102] 5) Fabricate the electron transport layer 500 on the inorganic passivation layer 400, and finally deposit the electrode layer 600 by evaporation to obtain the perovskite solar cell. The thickness of the electron transport layer 500 is 25 nm, and the thickness of the metal electrode is 100 nm.

[0103] Example 4

[0104] This example provides a preparation method for a perovskite solar cell, and the specific steps are as follows:

[0105] 1) Ultrasonically treat the transparent conductive layer 100 made of ITO with ITO cleaning agent, ultrapure water, isopropanol, and dishwashing liquid for 60 minutes. Then perform ultraviolet ozone treatment on the transparent conductive layer 100 for 10 minutes.

[0106] 2) Prepare the hole transport layer 200 on the transparent conductive layer 100. Select PTAA as the material for the hole transport layer 200, with the spin coating speed being 4000 rpm and the time being 30 seconds. After spin coating, place it on a hot plate at 100 °C for annealing treatment, and the annealing time is 10 minutes.

[0107] 3) Prepare the PbI2 thin film by spin coating. Take a PbI2 precursor solution of 700 mg / ml, with the volume ratio of DMF to NMP in the solvent being 9:1, the spin coating parameters being 3600 rpm, and the time being 3 seconds. After spin coating, soak it in isopropanol for 15 - 30 seconds, and then perform annealing at 60 °C for 2 minutes. Subsequently, spin coat the prepared organic ammonium salt mixture, with the concentration ratio of FAI:MASCN:NH4SCN being 90:15:5. Perform annealing at 135 °C in air for 60 minutes. Form the FAPbI3 perovskite thin film, that is, obtain the perovskite layer 300.

[0108] 4) On the perovskite layer 300, lead borate doped with PbBr2 (doping ratio 2:5) is used as the material, and an inorganic passivation layer 400 is prepared by spin coating. The spin coating parameter is 4000 rpm. After spin coating, annealing is carried out at 135 °C for 5 minutes to obtain the inorganic passivation layer 400.

[0109] 5) An electron transport layer 500 is fabricated on the inorganic passivation layer 400, and finally an electrode layer 600 is formed by evaporation to obtain a perovskite solar cell. The thickness of the electron transport layer 500 is 25 nm, and the thickness of the metal electrode is 100 nm.

[0110] Example 5

[0111] This example provides a method for preparing a perovskite solar cell, and the specific steps are as follows:

[0112] 1) The transparent conductive layer 100 made of ITO is ultrasonically treated with ITO cleaning agent, ultrapure water, isopropanol and dishwashing liquid for 60 minutes in sequence. Then the transparent conductive layer 100 is treated with ultraviolet ozone for 10 minutes.

[0113] 2) A hole transport layer 200 is prepared on the transparent conductive layer 100. PTAA is selected as the material of the hole transport layer 200. The spin coating speed is 4000 rpm and the time is 30 seconds. After spin coating, it is placed on a hot plate at 100 °C for annealing treatment, and the annealing time is 10 minutes.

[0114] 3) A PbI2 thin film is prepared by spin coating. A PbI2 precursor solution with a concentration of 700 mg / ml is taken, and the volume ratio of DMF to NMP in the solvent is 9:1. The spin coating parameter is 3600 rpm and the time is 3 seconds. After spin coating, it is soaked in isopropanol for 15 - 30 seconds, and then annealed at 60 °C for 2 minutes. Subsequently, the prepared organic ammonium salt mixture solution is spin coated, and the concentration ratio of FAI:MASCN:NH4SCN is 90:15:5. Annealing is carried out at 135 °C in air for 60 minutes to form a FAPbI3 perovskite thin film, that is, the perovskite layer 300 is obtained.

[0115] 4) On the perovskite layer 300, lead borate doped with PbI2 (doping ratio 2:5) is used as the material, and an inorganic passivation layer 400 is prepared by spin coating. The spin coating parameter is 4000 rpm. After spin coating, annealing is carried out at 135 °C for 5 minutes to obtain the inorganic passivation layer 400.

[0116] 5) An electron transport layer 500 is fabricated on the inorganic passivation layer 400, and finally an electrode layer 600 is formed by evaporation to obtain a perovskite solar cell. The thickness of the electron transport layer 500 is 25 nm, and the thickness of the metal electrode is 100 nm.

[0117] Comparative Example 1

[0118] It is only different from Example 1 in that step 4) is omitted, that is, the inorganic passivation layer 400 is not prepared.

[0119] The perovskite solar cells prepared in Examples 1-5 and Comparative Example 1 were tested for short-circuit current, open-circuit voltage, efficiency, and fill factor under the same test conditions. The results are shown in Table 1.

[0120] Table 1:

[0121]

[0122] Figure 3 This is the J-V curve diagram of the perovskite solar cells prepared in Examples 1-5 and Comparative Example 1 of this application. Combining Figure 3 with Table 1, it can be seen that the perovskite solar cells with an inorganic passivation layer are superior to those without an inorganic passivation layer in terms of short-circuit current, open-circuit voltage, efficiency, and fill factor. The open-circuit voltage and fill factor of the perovskite solar cells without lead borate passivation are significantly reduced. Among the various examples, Examples 2-5 using doped lead borate have better performance in test items such as short-circuit current, efficiency, and fill factor.

[0123] Figure 4 This is the scanning electron microscope (SEM) image of the perovskite layer after setting the inorganic passivation layer in Example 1 of this application; Figure 5 This is the scanning electron microscope (SEM) image of the perovskite layer after setting the inorganic passivation layer in Example 2 of this application; Figure 6 This is the scanning electron microscope (SEM) image of the perovskite layer in Comparative Example 1. From Figure 4 and Figure 5 it can be seen that the defects at the grain boundaries of the perovskite layer passivated with lead borate or Pb(SCN)2-doped lead borate are significantly reduced, and the crystal planes are larger. While Figure 6 as shown in

[0124] Figure 7 This is the stability test diagram of the perovskite solar cells prepared in Examples 1-2 and Comparative Example 1 of this application. The perovskite solar cells prepared in Examples 1-2 and Comparative Example 1 were tested for the percentage of their photoelectric efficiency under the same light conditions to investigate the decay rate of the photoelectric efficiency over time. As Figure 7As shown, for the perovskite solar cells of Examples 1-2 with an inorganic passivation layer, their stability is significantly better than that of Comparative Example 1 without an inorganic passivation layer. In addition, the stability of the perovskite solar cell passivated with Pb(SCN)2-doped lead borate is better than that of the lead borate passivation without any doping. The reason is that the introduction of thiocyanate ions can form a stable coordination structure with lead ions in the perovskite, which helps to inhibit the phase transition of the perovskite material and maintain its structural stability. Therefore, the doped lead borate as a passivation layer not only exhibits excellent optoelectronic efficiency but also excellent stability.

[0125] The embodiments of the present application further provide a photovoltaic module (not shown in the figure), which includes the perovskite solar cell provided in the above embodiments of the present application, or includes the perovskite solar cell prepared by the preparation method provided in the above embodiments.

[0126] As mentioned above, the above are only the specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application.

Claims

1. A perovskite battery, characterized in that: It comprises a transparent conductive layer, a photoelectric conversion layer and an electrode layer which are stacked in sequence, wherein the photoelectric conversion layer comprises a hole transport layer, a perovskite layer, an inorganic passivation layer and an electron transport layer which are stacked in sequence; wherein the D50 particle size of the grains of the perovskite layer is 0.73 μm to 1.65 μm.

2. The perovskite battery according to claim 1, characterized in that: The D50 grain size of the perovskite layer is 1.49 μm to 1.65 μm.

3. The perovskite battery according to claim 1 or 2, characterized in that: The material of the inorganic passivation layer is lead borate or doped lead borate.

4. The perovskite battery according to claim 3, characterized in that: When the material of the inorganic passivation layer is doped lead borate, the material of the inorganic passivation layer is selected from at least one of PbI2-doped lead borate, PbBr2-doped lead borate, PbCl2-doped lead borate and Pb(SCN)2-doped lead borate.

5. The perovskite battery according to claim 4, characterized in that: The doping ratio in the inorganic passivation layer is 1:1-10.

6. The perovskite battery according to claim 1, characterized in that: The thickness of the inorganic passivation layer is 1 nm to 8 nm.

7. The perovskite battery according to claim 1, characterized in that: The material of the transparent conductive layer is one of ITO, FTO or ZTO; or, The material of the hole transport layer is selected from PTAA, 2PACZ, NiO x and at least one of 4PADBC.

8. The perovskite battery according to claim 1, characterized in that: The hole transport layer is laminated to the transparent conductive layer, and the electron transport layer is laminated to the electrode layer; Alternatively, the electron transport layer is laminated to the transparent conductive layer, and the hole transport layer is laminated to the electrode layer.

9. The method for preparing a perovskite battery according to any one of claims 1 to 8, characterized in that: include: obtaining a transparent conductive layer; A photoelectric conversion layer is fabricated on the transparent conductive layer, wherein the photoelectric conversion layer comprises a hole transport layer, a perovskite layer, an inorganic passivation layer and an electron transport layer stacked in sequence, and the material of the inorganic passivation layer is lead borate or doped lead borate; An electrode layer is formed on the photoelectric conversion layer.

10. The method for preparing a perovskite battery according to claim 9, characterized in that: The step of manufacturing a photoelectric conversion layer on the transparent conductive layer comprises: Fabricating the hole transport layer on the transparent conductive layer; forming the perovskite layer on the hole transport layer; coating a slurry containing lead borate or doped lead borate on the perovskite layer, and performing annealing to obtain the inorganic passivation layer; The electron transport layer is fabricated on the inorganic passivation layer.

11. The method for preparing a perovskite battery according to claim 10, characterized in that: The step of forming the perovskite layer on the hole transport layer comprises: coating a solution containing a PbI2 precursor on the hole transport layer, and annealing the solution to obtain a PbI2 thin film; A solution containing an organic ammonium salt is coated on the PbI2 thin film and annealed to obtain the perovskite layer.

12. The method for preparing a perovskite battery according to claim 9, characterized in that: The steps of obtaining the transparent conductive layer include: Ultrasonic cleaning of the transparent conductive layer; The transparent conductive layer is subjected to ultraviolet ozone treatment.

13. A photovoltaic module, characterized in that: A perovskite battery comprising any one of claims 1-8, or a perovskite battery prepared by the method for preparing a perovskite battery according to any one of claims 9-12.

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