Solar cell and preparation method thereof, photovoltaic module and photovoltaic system

Abstract

The invention provides a solar cell and a preparation method thereof, a photovoltaic module and a photovoltaic system. The preparation method comprises the following steps: dissolving a perovskite precursor material in a polar solution to form a perovskite solution; a non-polar solvent is added into the perovskite solution, perovskite crystals are separated out, and a perovskite mixture with the perovskite crystals is generated; separating out the perovskite crystal from the perovskite mixture; carrying out annealing on the separated perovskite crystal; and carrying out thermal evaporation on the annealed perovskite crystal, uniformly depositing the perovskite crystal on a cell substrate, and depositing a perovskite thin film on the cell substrate to prepare the solar cell. According to the preparation method, the deposition accuracy of the perovskite thin film can be improved in a thermal evaporation deposition mode, so that the uniformity and crystallinity of the perovskite thin film in the solar cell can be improved, the defect density is reduced, the photoelectric conversion efficiency of the solar cell is improved, and meanwhile, the stability and reliability of the solar cell are improved.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and in particular to a solar cell and a preparation method thereof, a photovoltaic module and a photovoltaic system. Background Art

[0002] With the rapid development of the photovoltaic field, perovskite solar cells have become a typical representative of the new generation of photovoltaic power generation technology. Their advantages such as simple preparation process, diverse processing methods, low cost and high performance have attracted more and more attention, and their band gap is adjustable, which is significantly different from traditional crystalline silicon materials. At present, the efficiency of single-cell perovskite solar cells has increased from 3.8% to 26.1%, which is very close to the photoelectric conversion efficiency record of crystalline silicon solar cells, showing great industrialization potential.

[0003] However, in the related art, the uniformity of the perovskite film of the solar cell is insufficient, which in turn leads to the problem of insufficient photoelectric conversion efficiency of the solar cell and reduced stability and reliability.

[0004] Based on this, how to improve the stability and reliability of solar cells has become an urgent problem to be solved. Summary of the invention

[0005] The present invention provides a solar cell and a preparation method thereof, a photovoltaic module and a photovoltaic system to solve the technical problem of how to improve the stability and reliability of solar cells.

[0006] The embodiment of the present invention is implemented as follows: the present invention provides a solar cell and a preparation method thereof, a photovoltaic module and a photovoltaic system. A preparation method of a solar cell comprises: step S1, dissolving a perovskite precursor material in a polar solution to form a perovskite solution; step S2, adding a non-polar solvent to the perovskite solution to precipitate perovskite crystals and generate a perovskite mixture having the perovskite crystals; step S3, separating the perovskite crystals from the perovskite mixture; step S4, annealing the separated perovskite crystals; step S5, thermally evaporating the annealed perovskite crystals and uniformly depositing them on a cell substrate, depositing a perovskite film on the cell substrate to form a solar cell.

[0007] Furthermore, in step S1, the perovskite solution is a uniform perovskite solution.

[0008] Furthermore, in the step S1, the perovskite precursor material includes PbI2, PbCl2, CsBr and FAI.

[0009] Furthermore, in the step S1, the polar solution includes at least one of DMF solution, DMSO solution, methanol, ethanol, and tetrahydrofuran.

[0010] Furthermore, in step S2, the non-polar solvent includes at least one of petroleum ether, n-hexane, toluene, and chlorobenzene.

[0011] Furthermore, the step S2 specifically includes: step S21, adding the non-polar solvent to the perovskite solution at a rate of 1 to 2 drops per minute to precipitate the perovskite crystals and generate a perovskite mixed solution; S22, leaving the perovskite mixture to stand for at least 20 hours.

[0012] Further, step S3 specifically includes: the step S3 specifically includes: step S31, separating the perovskite crystals from the perovskite mixture through a filter; step S32, cleaning the perovskite crystals.

[0013] Furthermore, the step S4 specifically includes: step S41, placing the perovskite crystal in an annealing furnace for annealing; step S42, cooling the perovskite crystal.

[0014] Furthermore, the step S5 specifically includes: step S51, taking out the battery substrate and pre-treating the battery substrate; step S52, placing the perovskite crystal in a thermal evaporation device and fixing the battery substrate; step S53, heating the perovskite crystal so that the perovskite crystal gradually evaporates and is evenly deposited on the battery substrate, and coating the battery substrate.

[0015] Furthermore, in step S53, the evaporation rate of the perovskite crystal is controlled to be The evaporation temperature of the perovskite crystal is controlled to be between 150°C and 400°C.

[0016] Furthermore, the method further comprises the following steps: Step S6, performing annealing treatment on the solar cell.

[0017] An embodiment of the present invention further provides a solar cell, which is manufactured by the above-mentioned manufacturing method.

[0018] An embodiment of the present invention further provides a photovoltaic assembly, which includes the solar cell as described above.

[0019] An embodiment of the present invention further provides a photovoltaic system, which includes the photovoltaic assembly as described above.

[0020] The preparation method of the solar cell of the present invention prepares and generates perovskite crystals by means of a solution, thereby generating high-quality multi-component perovskite crystals. The generated perovskite crystals are thermally evaporated to generate a perovskite film on a cell substrate. The preparation method of the present invention can improve the accuracy of perovskite film deposition by means of thermal evaporation deposition, thereby improving the uniformity and crystallinity of the perovskite film in the solar cell, reducing the defect density, thereby improving the photoelectric conversion efficiency of the solar cell, and at the same time improving the stability and reliability of the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 is a flow chart of a method for preparing a solar cell provided by one embodiment of the present invention;

[0023] Figure 2 for Figure 1 A schematic diagram of a specific process of step S2 in the method for preparing a solar cell shown;

[0024] Figure 3 for Figure 1 A schematic diagram of a specific process of step S3 in the method for preparing a solar cell shown;

[0025] Figure 4 for Figure 1 A schematic diagram of a specific process of step S4 in the method for preparing a solar cell shown;

[0026] Figure 5 for Figure 1 The specific flow chart of step S5 in the method for preparing a solar cell is shown. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. In addition, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0028] In the description of the present invention, it is necessary to understand that the terms "length", "width", "up", "down", "top", "bottom", "lateral", "longitudinal" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention 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 therefore cannot be understood as a limitation on the present invention.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are merely examples, and the purpose is not to limit the present invention. In addition, the present invention may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use scenarios of other materials.

[0032] See also Figure 1 , Figure 1 This is a flow chart of a method for preparing a solar cell provided by the present invention. According to different requirements, the order of the steps in the flow chart can be changed, and some steps can be omitted, which is not limited here.

[0033] like Figure 1 As shown, the present invention provides a method for preparing a solar cell, which specifically includes:

[0034] Step S1, dissolving a perovskite precursor material in a polar solvent to form a perovskite solution;

[0035] Step S2, adding a non-polar solvent to the perovskite solution to precipitate perovskite crystals, thereby generating a perovskite mixture having perovskite crystals;

[0036] Step S3, separating perovskite crystals from the perovskite mixture;

[0037] Step S4, annealing the separated perovskite crystals;

[0038] Step S5, thermally evaporate the annealed perovskite crystals and uniformly deposit them on the battery substrate, and deposit a perovskite film on the battery substrate to form a solar cell.

[0039] Thus, the preparation method of the solar cell in the present invention prepares and generates perovskite crystals by means of a solution, thereby generating high-quality multi-component perovskite crystals. The generated perovskite crystals are thermally evaporated to generate a perovskite film on the cell substrate. The preparation method of the present invention can thus improve the accuracy of perovskite film deposition by means of thermal evaporation deposition, thereby improving the uniformity and crystallinity of the perovskite film in the solar cell, reducing the defect density, thereby improving the photoelectric conversion efficiency of the solar cell, and at the same time improving the stability and reliability of the solar cell.

[0040] It is understood that the solar cell in the present invention may specifically be a perovskite cell having a perovskite film. It is understood that the solar cell in the present invention may specifically include a cell substrate.

[0041] like Figure 1 As shown, specifically, in step S1, the perovskite precursor material is placed in a polar solution for dissolution to form a perovskite solution.

[0042] It is understood that the perovskite precursor material refers to the raw material used to form the perovskite structure in the process of preparing the perovskite solar cell. In one possible embodiment, the perovskite precursor material may include PbI2 (lead iodide), PbCl2 (lead chloride), CsBr (cesium bromide) and FAI (formamidine hydroiodide).

[0043] It is understood that polar solvents refer to solvents containing polar groups in the molecule to form permanent dipole moments. Polar solvents can effectively dissolve other polar or charged substances. In a possible embodiment, the polar solvent may include at least one of DMF solution, DMSO solution, methanol, ethanol, and tetrahydrofuran.

[0044] In a possible implementation, in step S1, the perovskite solution is a uniform perovskite solution. In this way, the perovskite film deposited on the cell substrate can be a uniform film, further improving the uniformity of the perovskite film in the solar cell, thereby improving the photoelectric conversion efficiency of the solar cell, and at the same time improving the stability and reliability of the solar cell.

[0045] Furthermore, after the perovskite precursor material is dissolved in a polar solvent to form a perovskite solution, a uniform perovskite solution can be formed by stirring. Therefore, the uniform perovskite solution can ensure that the solute is evenly distributed on the substrate during the deposition process, reduce local concentration fluctuations, thereby forming a more flat, pinhole-free dense film and improving the overall performance of the device. At the same time, the uniform perovskite solution can ensure that the perovskite material is uniformly crystallized during the solvent volatilization and annealing process, avoid crystallization defects caused by excessive or low local concentrations, increase the perovskite grain size, reduce grain boundaries, and improve carrier transfer efficiency.

[0046] like Figure 1 As shown, specifically, in step S2, a non-polar solvent is added to the perovskite solution generated in step S1 to precipitate perovskite crystals to generate a perovskite mixture having perovskite crystals.

[0047] It is understood that non-polar solvents refer to those solvents whose internal charge distribution is relatively uniform and do not have obvious positive and negative polarity or permanent dipole moment. Non-polar solvents are not good at dissolving polar or ionic compounds. In a possible embodiment, the non-polar solvent may include at least one of petroleum ether, n-hexane, toluene, and chlorobenzene.

[0048] In step S2, adding a non-polar solvent to the perovskite solution can reduce the overall polarity of the solution, thereby causing the pre-perovskite to precipitate in the form of crystals, thereby generating a perovskite mixed solution having perovskite crystals.

[0049] like Figure 1 and Figure 2 As shown, further, step S2 specifically includes: step S21, adding a non-polar solvent to the perovskite solution at a rate of 1 to 2 drops per minute to precipitate perovskite crystals and generate a perovskite mixed solution; step S22, leaving the perovskite mixed solution to stand for at least 20 hours.

[0050] It is understandable that, for the method of adding a non-polar solvent to the perovskite solution, in step S21, adding the non-polar solvent to the perovskite solution at a rate of 1 to 2 drops per minute can gradually change the polar environment in the solution, thereby accurately controlling the precipitation process of the perovskite crystals.

[0051] At the same time, slowly adding a non-polar solvent at a rate of 1 to 2 drops per minute helps to evenly reduce the polarity of the perovskite solution, avoid local environmental mutations that lead to too fast or uneven crystal formation, and enable the pre-perovskite to form crystals evenly and stably and grow slowly. In this way, perovskite crystals with uniform particle size and regular morphology can be obtained, and high-quality multi-component perovskite crystals are obtained, which also provides a more ideal material basis for subsequent thermal evaporation deposition, and ultimately helps to prepare dense and uniform perovskite films, improving the overall performance and stability of solar cells.

[0052] Furthermore, after the perovskite crystals are precipitated, the perovskite mixture containing the perovskite crystals can be subjected to a static treatment. In this way, the growth of the perovskite crystals can be promoted, and it is also beneficial for the impurities, bubbles, etc. that may exist in the perovskite mixture to be precipitated or escaped, so as to obtain high-quality multi-component perovskite crystals. In addition, such a sufficient static treatment ultimately provides a stable and uniform starting state for subsequent thermal evaporation deposition or other thin film preparation processes, which helps to form a dense and uniform perovskite film, thereby improving the overall performance and stability of solar cells.

[0053] Optionally, in step S22, the perovskite mixture may be left standing for, for example, 20 hours, 22 hours, 24 hours, 25 hours, 30 hours, etc. Preferably, the perovskite mixture may be left standing for 24 hours to provide more sufficient growth time for the perovskite crystals without wasting too much time.

[0054] like Figure 1 As shown, specifically, in step S3, the perovskite crystals are separated from the perovskite mixed solution having the perovskite crystals. In this way, the residual perovskite solution can be effectively removed, and only the precipitated perovskite crystals are retained.

[0055] like Figure 1 and Figure 3 As shown, further, step S3 specifically includes: step S31, separating the perovskite crystals from the perovskite mixture through a filter; step S32, washing the perovskite crystals to obtain relatively pure perovskite crystals. It can be understood that for the method of separating perovskite crystals. The perovskite crystals can be separated from the perovskite mixture through a filter. Then the separated perovskite crystals are washed. In this way, on the one hand, a higher purity precursor crystal can be obtained; on the other hand, it is also helpful to improve the uniformity and film quality of the material in the subsequent thermal evaporation deposition process, and finally form a dense and uniform perovskite film, thereby improving the performance and stability of solar cells.

[0056] Optionally, in step S32, the separated perovskite crystals may be washed multiple times with ether to remove the residual solvent and impurities on the perovskite crystals. It is understandable that when washing the perovskite crystals, the relatively light perovskite crystals need to be treated to prevent the perovskite crystals from being damaged.

[0057] like Figure 1 As shown, specifically, in step S4, the separated perovskite crystals are annealed. In this way, the heating during the annealing process can provide sufficient thermal energy for the perovskite crystals, so that the components can fully react and diffuse, thereby forming stable, high-quality perovskite crystals. At the same time, by annealing, the residual solvent and impurities on the perovskite crystals can be further removed to further obtain purer perovskite crystals.

[0058] like Figure 1 and Figure 4 As shown, further, step S4 specifically includes: S41, placing the perovskite crystal in an annealing furnace for annealing; S42, cooling the perovskite crystal.

[0059] It can be understood that, for the process of annealing the perovskite crystal, the perovskite crystal needs to be placed in an annealing furnace first. Then, the annealing furnace is turned on to anneal the perovskite crystal. The perovskite crystal is annealed in the annealing furnace at about 100°C for 1 to 2 hours to further remove residual solvents, ether and impurities to obtain a purer perovskite crystal. After that, the perovskite crystal obtained after annealing is cooled to room temperature.

[0060] Specifically, in step S5, after the perovskite crystals are generated in step S4, it is necessary to perform thermal evaporation on the generated perovskite crystals to deposit a uniform perovskite film on the battery substrate.

[0061] It is understandable that by thermally evaporating the perovskite crystals, the accuracy of solar cell coating can be improved and the uniformity of the perovskite film can be improved. For example, when coating the solar cell, the relative position between the solar cell and the perovskite crystal can be adjusted to achieve precise adjustment of the coating position of the perovskite film in the solar cell. For example, when coating the solar cell, the thickness of the perovskite film of the solar cell can be precisely controlled by adjusting the thermal evaporation temperature and thermal evaporation rate of the perovskite crystals.

[0062] Therefore, by thermally evaporating the generated perovskite crystals to deposit a uniform perovskite film on the cell substrate, the uniformity and crystallinity of the perovskite film in the solar cell can be improved and the defect density can be reduced.

[0063] like Figure 1and Figure 5 As shown, further, step S5 specifically includes: step S51, taking out the battery substrate and pre-treating the battery substrate; step S52, placing the perovskite crystal in a thermal evaporation device and fixing the battery substrate; step S53, heating the perovskite crystal so that the perovskite crystal gradually evaporates and is evenly deposited on the battery substrate, and coating the battery substrate.

[0064] It is understandable that in step S5, the battery substrate may be pre-treated by ultrasonic cleaning and plasma treatment to enhance the surface cleanliness and hydrophilicity of the battery substrate so that the surface of the battery substrate can be better coated, thereby improving the uniformity of the perovskite film of the solar cell and the overall performance of the solar cell.

[0065] It can be understood that, in step S5, the battery substrate may include conductive glass (FTO or ITO glass).

[0066] Afterwards, the perovskite crystal is placed in a thermal evaporation device, and the battery substrate is fixed to a position suitable for the deposition of the perovskite crystal. For example, the battery substrate can be placed below the perovskite crystal so that the perovskite crystal can be deposited on the surface of the battery substrate for coating after evaporation. Preferably, the perovskite crystal can be thermally evaporated in a high vacuum environment.

[0067] Finally, the perovskite crystals placed in the thermal evaporation device are heated so that the perovskite crystals gradually evaporate and are evenly deposited on the battery substrate to coat the battery substrate. After the perovskite crystals placed in the thermal evaporation device are heated, the perovskite crystals will gradually sublimate after being heated and turn into gaseous molecules. In a high vacuum environment, due to the long mean free path of gas molecules, these molecules can diffuse in all directions in a uniform manner and evenly deposit a coating on the pre-treated battery substrate. In an embodiment of the present invention, by regulating the heating temperature of the perovskite crystals, the evaporation rate, and the distance between the battery substrate and the perovskite crystals, the thickness and crystal quality of the perovskite film deposited on the battery substrate can be accurately controlled.

[0068] Further, in step S53, the evaporation rate of the perovskite crystal is controlled to be to The evaporation temperature of the perovskite crystal is controlled to be 150°C to 400°C. For example, the evaporation rate of the perovskite crystal can be controlled to be For example, the evaporation temperature of the perovskite crystal can be controlled to be 150°C, 180°C, 200°C, 220°C, 250°C, 280°C, 300°C, 350°C, 380°C, or 400°C.

[0069] Thus, in step S53, by controlling the evaporation rate of the perovskite crystal to to By controlling the evaporation temperature between 150°C and 400°C, the evaporation process of the perovskite crystal can be finely controlled. Specifically, the evaporation rate is controlled at to The evaporation rate helps to ensure that the perovskite material sublimates uniformly from the crystal and forms a consistent and continuous film on the battery substrate; at the same time, the evaporation temperature is controlled at 150℃ to 400℃, which can not only provide sufficient thermal energy for the perovskite crystal to promote its smooth sublimation, but also prevent the degradation of the perovskite crystal or the change of the crystal structure due to excessively high temperature.

[0070] like Figure 1 As shown, in a possible implementation manner, the method for preparing a solar cell according to an embodiment of the present invention further includes the following steps: Step S6, annealing the solar cell.

[0071] Specifically, the present invention can also perform annealing treatment on a solar cell coated with a perovskite film to optimize the crystallinity and interface performance of the perovskite film to improve the photoelectric conversion efficiency of the solar cell.

[0072] It can be understood that, in step S6, the annealing temperature of the solar cell may be 100° C. to 150° C., and the duration may be 10 minutes to 30 minutes.

[0073] For example, the annealing temperature of the solar cell may be 100°C, 110°C, 120°C, 130°C, 140°C, or 150°C.

[0074] For example, the annealing duration of the solar cell may be 10 minutes, 11 minutes, 15 minutes, 18 minutes, 20 minutes, 22 minutes, 25 minutes, 28 minutes, 30 minutes.

[0075] The method for preparing a solar cell provided by an embodiment of the present invention can improve the accuracy of perovskite film deposition by thermal evaporation deposition, thereby accurately controlling the uniformity of the perovskite film in the solar cell, thereby improving the photoelectric conversion efficiency of the solar cell. At the same time, the surface of the perovskite film of the solar cell can be made smooth, the particles are uniform, and there are no obvious defects and cracks. In addition, the stability and reliability of the solar cell can be improved, and the battery performance remains stable under continuous illumination and high temperature conditions without obvious degradation.

[0076] Next, a specific implementation of the method for preparing a solar cell provided in an embodiment of the present invention is described.

[0077] First, weigh 1 mmol of PbI2, 1 mmol of PbCl2, 1 mmol of CsBr and 1 mmol of FAI, dissolve them in 20 ml of DMF solvent, and stir until they are completely dissolved to form a uniform perovskite solution.

[0078] After that, 20 mL of chlorobenzene solvent was slowly added to the perovskite solution at a rate of about 1 to 2 drops per minute to obtain a perovskite mixture that ensures clear stratification. The perovskite mixture was allowed to stand for 24 hours to promote the growth of perovskite crystals.

[0079] After standing for 24 hours, distinct stratification was observed, with the lower layer being perovskite crystals and the upper layer being unreacted solvent. The perovskite crystals were separated from the solution using a filter.

[0080] Afterwards, the separated perovskite crystals were washed multiple times with ether to remove residual solvent and impurities. During the washing process, the crystals were handled gently to prevent damage.

[0081] After that, the cleaned perovskite crystal is placed in an annealing furnace and annealed at about 100°C for 2 hours to further improve the quality and purity of the perovskite crystal. After annealing, the perovskite crystal is cooled to room temperature.

[0082] After that, select a suitable battery substrate material, such as conductive glass (FTO or ITO glass), ultrasonic cleaning and plasma treatment to enhance the cleanliness and hydrophilicity of the battery substrate.

[0083] Afterwards, the prepared perovskite crystals are placed in a thermal evaporation device with the cell substrate in place.

[0084] In 10 -6 Under a high vacuum environment of 2000 Å, the perovskite crystals are heated so that they gradually evaporate and are evenly deposited on the battery substrate. During evaporation, the evaporation rate and temperature are controlled to ensure the uniformity and density of the generated perovskite film. The evaporation rate is controlled to be approximately The temperature is controlled between 200℃.

[0085] Finally, the solar cells deposited with perovskite films were annealed at 125°C for 25 minutes to optimize the crystallinity and interface properties of the films.

[0086] In this way, high-quality multi-component perovskite films can be prepared in solar cells.

[0087] The present invention also provides a solar cell, which can be prepared by the above-mentioned method for preparing a solar cell.

[0088] The photovoltaic system in the embodiment of the present invention may include the photovoltaic module in the embodiment of the present invention, and the photovoltaic module in the embodiment of the present invention may include a plurality of solar cells, and the plurality of solar cells may be connected in series in sequence through welding strips to form a battery string. The battery strings in the photovoltaic module may be connected in series, in parallel, or in series-parallel combination to realize the current bus output, for example, the connection between the battery strings may be realized through a bus bar.

[0089] In the embodiments of the present invention, the photovoltaic system can be applied to photovoltaic power stations, such as ground power stations, rooftop power stations, water surface power stations, etc., and can also be applied to equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is, the photovoltaic system can be applied in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array may be an array combination of multiple photovoltaic components. For example, multiple photovoltaic components can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter to convert it into the alternating current required by the mains power grid and then connected to the mains network to realize solar power supply.

[0090] It is understandable that in such an embodiment, the photovoltaic module may also include a frame, a back plate, photovoltaic glass and an adhesive film. The adhesive film may be filled between the front and back of the cell and between the photovoltaic glass and adjacent cells, etc. As a filler, it may be a transparent colloid with good light transmittance and aging resistance. For example, the adhesive film may be an EVA adhesive film or a POE adhesive film, which may be selected according to actual conditions and is not limited here.

[0091] Photovoltaic glass can cover the adhesive film on the front of the cell. Photovoltaic glass can be ultra-white glass, which has high light transmittance, high transparency, and excellent physical, mechanical and optical properties. For example, the light transmittance of ultra-white glass can reach more than 92%, which can protect the cell without affecting the efficiency of the cell as much as possible. At the same time, the adhesive film can bond the photovoltaic glass and the cell together. The presence of the adhesive film can seal and insulate the cell and make it waterproof and moisture-proof.

[0092] The backplane can be attached to the film on the back of the cell. The backplane can protect and support the cell and has reliable insulation, water resistance and aging resistance. There are multiple options for the backplane, usually tempered glass, organic glass, aluminum alloy TPT composite film, etc. It can be set according to the specific situation and is not limited here. The whole composed of the backplane, cell, film and photovoltaic glass can be set on the frame. The frame serves as the main external support structure of the entire photovoltaic module and can provide stable support and installation for the photovoltaic module. For example, the photovoltaic module can be installed at the required location through the frame.

[0093] In the description of this specification, the description with reference to the terms "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0094] In addition, the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing a solar cell, characterized in that: include: Step S1, dissolving a perovskite precursor material in a polar solution to form a perovskite solution; Step S2, adding a non-polar solvent to the perovskite solution to precipitate perovskite crystals, thereby generating a perovskite mixture having the perovskite crystals; Step S3, separating the perovskite crystals from the perovskite mixture; Step S4, annealing the separated perovskite crystals; Step S5, thermally evaporate the annealed perovskite crystals and uniformly deposit them on a battery substrate, and deposit a perovskite film on the battery substrate to manufacture a solar cell.

2. The method for preparing a solar cell according to claim 1, characterized in that: In the step S1, the perovskite solution is a uniform perovskite solution.

3. The method for preparing a solar cell according to claim 1, characterized in that: In the step S1, the perovskite precursor material includes PbI2, PbCl2, CsBr and FAI.

4. The method for preparing a solar cell according to claim 1, characterized in that: In the step S1, the polar solution includes at least one of DMF solution, DMSO solution, methanol, ethanol, and tetrahydrofuran.

5. The method for preparing a solar cell according to claim 1, characterized in that: In step S2, the non-polar solvent includes at least one of petroleum ether, n-hexane, toluene, and chlorobenzene.

6. The method for preparing a solar cell according to claim 1, characterized in that: The step S2 specifically includes: Step S21, adding the non-polar solvent to the perovskite solution at a rate of 1 to 2 drops per minute to precipitate the perovskite crystals to generate a perovskite mixed solution; Step S22, leaving the perovskite mixture to stand for at least 20 hours.

7. The method for preparing a solar cell according to claim 1, characterized in that: The step S3 specifically includes: Step S31, separating the perovskite crystals from the perovskite mixture through a filter; Step S32, cleaning the perovskite crystal.

8. The method for preparing a solar cell according to claim 1, characterized in that: The step S4 specifically includes: Step S41, placing the perovskite crystal into an annealing furnace for annealing; Step S42, cooling the perovskite crystal.

9. The method for preparing a solar cell according to claim 1, characterized in that: The step S5 specifically includes: Step S51, taking out the battery substrate and pre-treating the battery substrate; Step S52, placing the perovskite crystal in a thermal evaporation device and fixing the battery substrate; Step S53, heating the perovskite crystals to make the perovskite crystals gradually evaporate and uniformly deposit on the battery substrate, thereby coating the battery substrate.

10. The method for preparing a solar cell according to claim 9, characterized in that: In step S53, the evaporation rate of the perovskite crystal is controlled to to The evaporation temperature of the perovskite crystal is controlled to be 150°C to 400°C.

11. The method for preparing a solar cell according to claim 1, characterized in that: The method further comprises the following steps: Step S6, performing annealing treatment on the solar cell.

12. A solar cell, characterized in that: The solar cell is manufactured by the manufacturing method according to any one of claims 1 to 11.

13. A photovoltaic module, characterized in that: The photovoltaic module comprises the solar cell according to claim 12.

14. A photovoltaic system, characterized in that: The photovoltaic system comprises the photovoltaic assembly according to claim 13.

Images