Preparation method for perovskite thin film, and laminated solar cell and preparation method therefor

Abstract

A preparation method for a perovskite thin film, and a laminated solar cell and a preparation method therefor. The preparation method for a perovskite thin film comprises the following steps: S1, preparing a mixed shape-preserving thin film of lead iodide and cesium bromide for shape preservation on a surface of a substrate; S2, performing scribing on the mixed shape-preserving thin film by using a laser scribing process to prepare a patterned groove; and S3, with an ammonium salt precursor solution being included, coating the ammonium salt precursor solution onto the surface of the mixed shape-preserving thin film obtained in S2, and after coating is finished, subjecting a substrate to an annealing treatment.

Description

A perovskite film preparation method, stacked solar cell and preparation method

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on December 19, 2023, with application number 202311746137.7, and invention name “A method for preparing a perovskite thin film, a stacked solar cell and a preparation method”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of perovskite solar cells, and in particular to a method for preparing a perovskite thin film, a stacked solar cell and a preparation method thereof. Background Art

[0003] The statements herein merely provide background information related to the present application and do not necessarily constitute prior art.

[0004] Solar energy is a highly anticipated new clean energy source, boasting the advantages of abundant resources and low costs. Currently, photovoltaic cells are one of the most efficient ways to convert solar energy into electricity, and single-crystal silicon and polycrystalline silicon solar cells have achieved relatively mature industrialization. In recent years, perovskite / crystalline silicon tandem technology has become a research hotspot in the photovoltaic field, garnering widespread attention. The development of this technology is crucial for improving the photoelectric conversion efficiency of solar cells and reducing manufacturing costs, thereby promoting the further development and application of solar power generation technology. The theoretical effective photoelectric conversion efficiency of crystalline silicon / perovskite tandem solar cells is as high as over 40%, far exceeding that of crystalline silicon solar cells. The basic principle of perovskite / crystalline silicon tandem technology is to stack perovskite and crystalline silicon materials to form a heterojunction. This technology leverages the wide bandgap, high absorption coefficient, and high carrier mobility of the perovskite material with the stability and excellent electron transport properties of the crystalline silicon material to improve the photoelectric conversion efficiency of solar cells.

[0005] For most of the currently available crystalline silicon / perovskite tandem solar cells, the use of a textured crystalline silicon substrate is an inevitable option to further improve the performance of crystalline silicon / perovskite tandem solar cells. However, due to the unique unevenness of the textured substrate, the perovskite film prepared using a solution wet method cannot be fully and conformally covered on the textured substrate, resulting in a short circuit in the device. In order to prepare a conformal, fully covered perovskite film on a textured crystalline silicon substrate, a two-step method of evaporation and solution is usually adopted. That is, the first step is to use the evaporation method to prepare a conformal lead iodide and cesium bromide mixed conformal film, and the second step is to use a mixed ammonium salt solution to react with the evaporated film to form a conformal perovskite film.

[0006] However, in this traditional two-step process, the lead iodide near the top surface of the conformal hybrid film is more likely to react completely with the ammonium salt solution. The lead iodide near the bottom surface of the film, which is not in direct contact with the ammonium salt solution, is less likely to react completely, ultimately forming a large amount of lead iodide residue in the lower layer of the perovskite film. This free lead iodide forms numerous defects within the perovskite film, resulting in low-quality perovskite films and thus affecting the performance of perovskite solar cells.

[0007] Therefore, it is necessary to study a new technical solution to solve the above problems. Application Contents

[0008] The purpose of the embodiments of the present application is to provide a method for preparing a perovskite film, a stacked solar cell and a preparation method, which introduces a laser patterning process during the production of the perovskite film. This process step can further ensure the sufficient and efficient reaction of the lead iodide and cesium bromide mixed conformal film with the subsequent ammonium salt precursor solution, thereby forming a higher quality perovskite film, thereby effectively improving the performance of the stacked solar cell.

[0009] The technical solution adopted in the embodiment of this application is:

[0010] In a first aspect, a method for preparing a perovskite thin film is provided, comprising a substrate and the following steps:

[0011] S1, preparing a conformal mixed thin film of lead iodide and cesium bromide on the surface of the substrate for conformal application;

[0012] S2, scribing the hybrid conformal film using a laser scribing process to form patterned grooves on the hybrid conformal film;

[0013] S3, including applying an ammonium salt precursor solution to the surface of the mixed conformal film obtained in S2, and then annealing the substrate after the coating is completed.

[0014] In one embodiment, in S1, the lead iodide and the cesium bromide are prepared on the surface of the substrate by a binary co-evaporation method, wherein: the evaporation rate of the lead iodide is 0-10A / s, the evaporation rate of the cesium bromide is 0-10A / s, and the evaporation time is 0-10000s; the thickness of the mixed conformal film is 200-800nm; and the evaporation rate ratio of the lead iodide to the cesium bromide is between 10:1 and 2:1.

[0015] In one embodiment, in S2 , the width of the scribe line is 0-50 μm, and the depth of the scribe line is 0-800 nm.

[0016] In one embodiment, the scribing pattern is a grid of squares, the grid side length is 0-100 mm, and the laser power is 0-90 W.

[0017] In one embodiment, the scribing depth is 250 nm and the grid side length is 10 mm.

[0018] In one embodiment, in S3, the ammonium salt precursor solution is disposed on the surface of the hybrid conformal film by spin coating; wherein: the spin coating speed is 1200-6000 rpm, the spin coating time is 20-120 s, the annealing temperature is 50-150° C., and the annealing time is 5-40 min.

[0019] In one embodiment, the ammonium salt precursor solution comprises formamidine iodide (FAI) and formamidine bromide (FABr) in a certain molar ratio dissolved in an organic solvent, wherein the molar ratio of the formamidine iodide to the formamidine bromide is between 10:1 and 1:10.

[0020] In a second aspect, a stacked solar cell is provided, which comprises, from bottom to top, a first metal electrode layer, a first transparent electrode layer, a P-type base doping layer, a base back passivation layer, a velvet silicon substrate, a base surface passivation layer, an N-type base doping layer, a tunneling layer, a hole transport layer, a perovskite absorption layer, a passivation layer, an electron transport layer, a buffer layer, a second transparent electrode layer, a second metal electrode layer, and an anti-reflection layer; wherein: the perovskite absorption layer is obtained by the perovskite thin film preparation method provided in any of the above embodiments.

[0021] In a third aspect, a method for preparing a stacked solar cell is provided, which is used to prepare the stacked solar cell provided in the above embodiment, comprising the following steps:

[0022] Step 1: sequentially preparing a substrate back passivation layer and a P-type substrate doping layer on the back of the textured silicon substrate, and sequentially preparing a substrate surface passivation layer and an N-type substrate doping layer on the surface of the textured silicon substrate;

[0023] Step 2: preparing a first transparent electrode layer on the back side of the P-type base doping layer;

[0024] Step 3: preparing a first metal electrode layer on the back of the first transparent electrode layer;

[0025] Step 4: preparing a tunneling layer on the surface of the N-type base doping layer;

[0026] Step 5: preparing a hole transport layer on the surface of the tunneling layer;

[0027] Step 6: preparing a perovskite absorption layer on the surface of the hole transport layer;

[0028] Step 7: preparing a passivation layer on the surface of the perovskite absorption layer;

[0029] Step eight: preparing an electron transport layer on the surface of the passivation layer;

[0030] Step nine: preparing a buffer layer on the surface of the electron transport layer;

[0031] Step 10: preparing a second transparent electrode layer on the surface of the buffer layer;

[0032] Step 11: preparing a second metal electrode layer on the surface of the second transparent electrode layer;

[0033] Step 12: preparing an anti-reflection layer on the surface of the second metal electrode layer.

[0034] In one embodiment, in step 2, the substrate sample of step 1 is placed in a magnetron sputtering device using a magnetron sputtering method, an ITO target is set, the power is controlled to 60 W, and the operation time is 1.5 hours.

[0035] In one embodiment, in step 3, the substrate sample in step 2 is placed on the mask by evaporation, and placed in the evaporation chamber. The vacuum degree of evaporation is 2×10 -4 Pa, the evaporation voltage and evaporation temperature were adjusted, the evaporation rate was controlled at 2.5Å / S, and silver was evaporated onto the film.

[0036] In one embodiment, in step 4, the substrate sample in step 3 is placed on the mask by magnetron sputtering, and the device is placed in a magnetron sputtering device with a control power of 60 W and a running time of 1 hour.

[0037] In one embodiment, in step five, the hole transport layer dispersion is evenly coated on the surface of the substrate sample in step four by spin coating, and the spin coating speed is set to 2000 rpm, the spin coating time is 40 s, and the solution volume is 100 ul; after the spin coating is completed, an annealing operation is performed, the annealing temperature is 450° C., and the annealing time is 30 min.

[0038] In one embodiment, in step seven, the substrate sample in step six is ​​placed on the mask by evaporation, and placed in the evaporation chamber, and the evaporation vacuum is 2×10 -4 Pa, the evaporation voltage is adjusted to the evaporation temperature, the evaporation rate is controlled at 0.1Å / S, and propylene diamine iodine is evaporated onto the layer film; after the evaporation is completed, the annealing operation is performed, the annealing temperature is 100℃, and the annealing time is 8min.

[0039] In one embodiment, in step eight, the substrate sample in step seven is placed on the mask by evaporation, and placed in the evaporation chamber, and the evaporation vacuum is 1×10 -4 Pa, the evaporation voltage was adjusted to the evaporation temperature, the evaporation rate was controlled at 0.1-0.15Å / S, and C60 was evaporated onto the film.

[0040] In one embodiment, in step nine, SnO2 is evaporated onto the film by atomic deposition, and the vacuum degree of the atomic deposition equipment is set to 0.5×10 -4 Pa, the deposition pipe temperature is 60 °C, and the deposition chamber temperature is 70 °C.

[0041] The beneficial effects of the perovskite film preparation method, stacked solar cell and preparation method provided in the embodiments of the present application are: the present application introduces a laser patterning process in the production of the perovskite film, and this process step can further ensure the sufficient and efficient reaction of the lead iodide and cesium bromide mixed conformal film with the subsequent ammonium salt precursor solution, thereby forming a higher quality perovskite film, thereby effectively improving the performance of the stacked solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or exemplary technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0043] FIG1 is a schematic structural diagram of the stacked solar cells of Examples 1 to 6 of the present application;

[0044] FIG2 is a schematic diagram of the process for preparing a perovskite film in Example 1 of the present application;

[0045] FIG3 is a schematic diagram of the process for preparing perovskite films in Examples 2 to 6 of the present application;

[0046] FIG4 is a schematic diagram of laser scribing patterning in Examples 2 to 6 of the present application;

[0047] FIG5 is a performance test diagram of the stacked solar cells in Examples 1 to 6 of the present application.

[0048] Description of the accompanying drawings:

[0049] 110. First metal electrode layer; 111. First transparent electrode layer; 112. P-type substrate doping layer; 113. Substrate back passivation layer; 114. Textured silicon substrate; 115. Substrate surface passivation layer; 116. N-type substrate doping layer; 117. Tunneling layer; 211. Hole transport layer; 212. Perovskite absorption layer; 213. Passivation layer; 214. Electron transport layer; 215. Buffer layer; 216. Second transparent electrode layer; 217. Second metal electrode layer; 218. Anti-reflection layer. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit this application.

[0051] It should be noted that when a component is referred to as being "fixed on" or "disposed on" another component, it may be directly on the other component or indirectly on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The terms "upper", "lower", "left", "right", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of description and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on this application. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. The terms "first" and "second" are only used for the purpose of convenience of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0052] In order to illustrate the technical solution provided by this application, a detailed description is given below with reference to specific drawings and embodiments.

[0053] 1 to 5 , which illustrate various embodiments of a perovskite thin film preparation method, a stacked solar cell, and a preparation method thereof according to the present application.

[0054] Example 1: A method for preparing a stacked solar cell without laser patterning of the scribing depth, specifically:

[0055] The structure of the stacked solar cell is, from bottom to top, the first metal electrode layer 110, the first transparent electrode layer 111, the P-type base doping layer 112, the base back passivation layer 113, the textured silicon substrate 114, the base surface passivation layer 115, the N-type base doping layer 116, the tunneling layer 117, the hole transport layer 211, the perovskite absorption layer 212, the passivation layer 213, the electron transport layer 214, the buffer layer 215, the second transparent electrode layer 216, the second metal electrode layer 217, and the anti-reflection layer 218. The preparation method is as follows:

[0056] Step 1: a backside passivation layer 113 and a P-type doped base layer 112 are sequentially formed on the backside of the textured silicon substrate 114 , and a surface passivation layer 115 and an N-type doped base layer 116 are sequentially formed on the surface of the textured silicon substrate 114 .

[0057] Step 2: Prepare a first transparent electrode layer 111 on the back side of the P-type base doped layer 112. Typically, magnetron sputtering is used. Place the base sample from Step 1 in a magnetron sputtering apparatus with an ITO target, control the power to 60 W, and run for 1.5 hours. The thickness of the first transparent electrode layer 111 can be 100 nm.

[0058] Step 3: Prepare the first metal electrode layer 110 on the back of the first transparent electrode layer 111. Usually, the evaporation method is used. The substrate sample of step 2 is placed on the mask and placed in the evaporation chamber. The vacuum degree of evaporation is 2×10 -4 Pa, the evaporation voltage and evaporation temperature are adjusted, the evaporation rate is controlled at 2.5Å / S, and silver is evaporated onto the film. The film thickness of the first metal electrode layer 110 can be 200nm.

[0059] Step 4: Form a tunneling layer 117 on the surface of the N-type base doped layer 116. This is typically done using magnetron sputtering. The base sample from Step 3 is placed on a mask and then in a magnetron sputtering machine. The sputtering power is controlled at 60W and the machine is operated for 1 hour. The thickness of the tunneling layer 117 can be 40nm.

[0060] Step 5: Prepare a hole transport layer 211 on the surface of the tunneling layer 117. Treat the substrate sample from step 4 with UV-Ozone for 15 minutes. Prepare a hole transport layer 211 dispersion. Dissolve 0.05 mol of NiOx powder in 1 ml of ultrapure water and ultrasonicate for 20 minutes. Spin coat the sample surface with the hole transport layer 211 dispersion evenly. Set the spin coating speed to 2000 rpm, the spin coating time to 40 seconds, and the solution volume to 100 μl. After spin coating, perform an annealing operation at 450°C for 30 minutes. The hole transport layer 211 can have a film thickness of 20 nm.

[0061] Step six: Prepare a perovskite absorption layer 212 on the surface of the hole transport layer 211. The perovskite absorption layer 212 is usually prepared by a two-step evaporation solution method based on co-evaporation. Specifically, the first step is to use a co-evaporation evaporation method to prepare a conformal mixed conformal film of lead iodide and cesium bromide on the substrate. This step uses binary co-evaporation, the evaporation rate of lead iodide is 8A / s, the evaporation rate of cesium bromide is controlled at 0.8A / s, the total evaporation time is controlled between 1000s, and the thickness of the formed film is 440nm; at the same time, the mass ratio of lead iodide to cesium bromide is controlled at 10:1. The second step is to prepare an ammonium salt precursor solution and evenly coat the ammonium salt precursor solution on the surface of the mixed conformal film prepared in the first step. The spin coating speed is 5000rpm and the spin coating time is 30s. After the spin coating is completed, an annealing operation is performed, the annealing temperature is 150°C, and the annealing time is 10 min. The ammonium salt precursor solution consists of formamidine iodide (FAI), formamidine bromide (FABr), and an additive such as methylammonium chloride (MACl) dissolved in an organic solvent at a stoichiometric ratio of 1:4.7. The proportion of methylammonium chloride (MACl) relative to the other two ammonium salt additives is 10% by weight, and the solution concentration is controlled at 1M (mol / L).

[0062] Step 7: Prepare a passivation layer 213 on the surface of the perovskite absorption layer 212. Using the evaporation method, weigh 3 mg of propylene diamine iodide and place it in a crucible. Place the substrate sample from step 6 on the mask and place it in the evaporation chamber. Wait until the evaporation vacuum is 2×10 -4 Pa, evaporation is performed, the evaporation voltage is adjusted to the evaporation temperature, and the evaporation rate is controlled at 0.1 Å / s. Propylene diamine iodide is evaporated onto the film. The passivation layer 213 can be 4 nm thick. After completion, the annealing table temperature is set to 100°C and annealing is performed for 8 minutes.

[0063] Step 8: Prepare the electron transport layer 214 on the surface of the passivation layer 213. Using the evaporation method, place the substrate sample in step 7 on the mask and put it into the evaporation chamber. Wait for the evaporation vacuum to be 1×10 -4 Pa, the evaporation voltage is adjusted to the evaporation temperature, and the evaporation rate is controlled at 0.1-0.15 Å / s to evaporate C60 onto the film. The thickness of the electron transport layer 214 can be 20 nm.

[0064] Step 9: Prepare a buffer layer 215 on the surface of the electron transport layer 214. Using atomic deposition, set the vacuum degree of the atomic deposition equipment to 0.5×10 -4 Pa, the deposition channel temperature is between 60℃, the deposition chamber temperature is 70℃, SnO2 is evaporated onto the layer film, and the thickness can be 15nm.

[0065] Step 10: Prepare a second transparent electrode layer 216 on the surface of the buffer layer 215. Similar to the preparation of the first transparent electrode layer 111, set an IZO target, control the power to 50W, and run for 1 hour. The thickness of the second transparent electrode layer 216 can be 100nm.

[0066] Step 11: Prepare a second metal electrode layer 217 on the surface of the second transparent electrode layer 216. This is similar to preparing the first metal electrode layer 110. The thickness of the second metal electrode layer 217 can be 100 nm.

[0067] Step 12: Prepare an anti-reflection layer 218 on the second metal electrode layer 217. Similar to the preparation of the second passivation layer 213, magnesium fluoride is evaporated onto the film at an evaporation rate of 2 Å / s. The thickness of the anti-reflection layer 218 can be 100 nm.

[0068] Example 2: Preparation method of perovskite solar cell based on laser patterning with a scribing depth of 100 nm.

[0069] This embodiment 2 is basically the same as embodiment 1, and in step 6 thereof, a laser patterning process step is added as follows:

[0070] After preparing the first step of the hybrid conformal film, a laser scribing process was used to create patterned grooves on the film. The laser power was set at 60W, the line width was controlled at 30μm, and the line depth was controlled at 100nm. The scribing pattern was a square grid with a grid side length of 10mm.

[0071] Example 3: Preparation method of perovskite solar cell based on laser patterning with a scribing depth of 250 nm.

[0072] This embodiment 3 is basically the same as embodiment 1, and in step 6 thereof, a laser patterning process step is added as follows:

[0073] After the first step of preparing the hybrid conformal film, a laser scribing process was used to create patterned grooves on the film. The laser power was set at 60W, the line width was controlled at 30μm, and the line depth was controlled at 250nm. The scribing pattern was a square grid with a grid side length of 10mm.

[0074] Example 4: Preparation method of perovskite solar cell based on laser patterning with a scribing depth of 500 nm.

[0075] This embodiment 4 is basically the same as embodiment 1, and in step 6 thereof, a laser patterning process step is added as follows:

[0076] After the first step of preparing the hybrid conformal film, a laser scribing process was used to create patterned grooves on the film. The laser power was set at 60W, the line width was controlled at 30μm, and the line depth was controlled at 500nm. The scribing pattern was a square grid with a grid side length of 10mm.

[0077] Example 5: Preparation method of perovskite solar cell based on laser patterning with a grid side length of 1 mm.

[0078] This embodiment 5 is basically the same as embodiment 1, and in step 6 thereof, a laser patterning process step is added as follows:

[0079] After the first step of preparing the hybrid conformal film, a laser scribing process was used to create patterned grooves on the film. The laser power was set at 60W, the line width was controlled at 30μm, and the line depth was controlled at 250nm. The scribing pattern was a square grid with a grid side length of 1mm.

[0080] Example 6: Preparation method of perovskite solar cell based on laser patterning with a grid side length of 100 mm.

[0081] This embodiment 6 is basically the same as embodiment 1, and in step 6, a laser patterning process step is added as follows:

[0082] After the first step of preparing the hybrid conformal film, a laser scribing process was used to create patterned grooves on the film. The laser power was set at 60W, the scribing width was controlled at 30μm, and the scribing depth was controlled at 250nm. The scribing pattern was a square grid with a grid side length of 100mm.

[0083] Refer to Figure 5. Using a solar simulator, a standard solar intensity calibration is performed and an area of ​​1.0 cm 2 The device of the embodiment is subjected to long-term IV testing, with the starting voltage set to 1.95V, the cut-off voltage set to 0V, the range set to 100 mA, and the result rounded to two decimal places. The test results are shown in FIG5 .

[0084] As shown in FIG2 , the perovskite film prepared by the preparation method of the perovskite solar cell based on the non-scribe depth laser patterning in Example 1 has a low quality because the reaction between the mixed conformal film in the first step and the ammonium salt solution in the second step is incomplete, and the ammonium salt solution has difficulty penetrating into the bottom of the mixed conformal film prepared in the first step.

[0085] As shown in Figure 3, in Examples 2-6, the hybrid conformal film processed through the laser patterning process has a larger reactive surface area, allowing for a more complete reaction with the subsequent ammonium salt solution. The ammonium salt solution also has better contact with the interior and bottom of the hybrid conformal film through the patterned structure. The perovskite film produced using the laser patterning process is free of lead iodide residue, improving film quality.

[0086] Judging from the performance of the perovskite solar cells of different embodiments, the solar cells of Examples 2-6 prepared using the laser patterning process performed far better than the solar cell prepared in Example 1. Specifically, the photoelectric conversion efficiency, short-circuit current, and open-circuit voltage of the solar cell prepared in Example 1 were higher than those of the other embodiments. Furthermore, the attenuation rate of the perovskite solar cell of Example 1 was as high as 8.7% per year, while the attenuation rates of the perovskite solar cells of Examples 2-6 were all less than 1% per year.

[0087] This application also optimizes the grid side length and line depth for the laser patterning process. Optimization results show that for this laser patterning process, the best results are achieved when the line depth is 250nm and the grid side length is 10mm. This is reflected in the stacked device in Example 3, based on these optimized parameters, achieving higher photoelectric conversion efficiency and open-circuit voltage than those in Examples 2, 4, 5, and 6.

[0088] The design focus of this application is that it mainly provides a method for preparing high-quality conformal perovskite films based on laser patterning process; this method introduces laser patterning process in the production of perovskite films. This process step can further ensure the full and efficient reaction of the lead iodide and cesium bromide mixed conformal film with the subsequent ammonium salt solution, thereby forming a higher quality perovskite film, thereby effectively improving the performance of the stacked solar cell.

[0089] The above are merely optional embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included within the scope of the claims of the present application.

Claims

1. A method for preparing a perovskite film, comprising a substrate, characterized in that: It also includes the following steps: S1, preparing a conformal mixed film of lead iodide and cesium bromide on the surface of the substrate for conformal use; S2, scribing the hybrid conformal film using a laser scribing process to prepare a patterned groove on the hybrid conformal film; S3, including an ammonium salt precursor solution, coating the ammonium salt precursor solution on the surface of the mixed conformal film completed in S2, and after coating, annealing the substrate.

2. The method for preparing a perovskite thin film according to claim 1, characterized in that: In S1, the lead iodide and the cesium bromide are prepared on the surface of the substrate by a binary co-evaporation method, wherein: the evaporation rate of the lead iodide is 0-10A / s, the evaporation rate of the cesium bromide is 0-10A / s, and the evaporation time is 0-10000s; the thickness of the mixed conformal film is 200-800nm; and the evaporation rate ratio of the lead iodide to the cesium bromide is between 10:1 and 2:

1.

3. The method for preparing a perovskite thin film according to claim 2, characterized in that: In S2, the scribe width is 0-50um and the scribe depth is 0-800nm.

4. The method for preparing a perovskite thin film according to claim 3, characterized in that: The scribing pattern is a grid-like square with a grid side length of 0-100mm and a laser power of 0-90W.

5. The method for preparing a perovskite thin film according to claim 4, characterized in that: The scribing depth is 250 nm and the grid side length is 10 mm.

6. The method for preparing a perovskite thin film according to claim 1, characterized in that: In S3, the ammonium salt precursor solution is disposed on the surface of the mixed conformal film by spin coating; wherein: the spin coating speed is 1200-6000 rpm, the spin coating time is 20-120 s, the annealing temperature is 50-150° C., and the annealing time is 5-40 min.

7. The method for preparing a perovskite thin film according to claim 6, characterized in that: The ammonium salt precursor solution comprises formamidine iodide (FAI) and formamidine bromide (FABr) in a certain molar ratio dissolved in an organic solvent, wherein the molar ratio of the formamidine iodide to the formamidine bromide is between 10:1 and 1:

10.

8. A laminated solar cell, characterized in that: The stacked solar cell comprises, from bottom to top, a first metal electrode layer, a first transparent electrode layer, a P-type substrate doping layer, a substrate back passivation layer, a suede silicon substrate, a substrate surface passivation layer, an N-type substrate doping layer, a tunneling layer, a hole transport layer, a perovskite absorption layer, a passivation layer, an electron transport layer, a buffer layer, a second transparent electrode layer, a second metal electrode layer, and an anti-reflection layer; wherein: The perovskite absorption layer is prepared by the perovskite thin film preparation method according to any one of claims 1 to 7.

9. A method for preparing a laminated solar cell, for preparing the laminated solar cell according to claim 8, characterized in that: The steps include: Step 1: sequentially preparing a substrate back passivation layer and a P-type substrate doping layer on the back of the textured silicon substrate, and sequentially preparing a substrate surface passivation layer and an N-type substrate doping layer on the surface of the textured silicon substrate; Step 2: preparing a first transparent electrode layer on the back side of the P-type substrate doping layer; Step 3: preparing a first metal electrode layer on the back of the first transparent electrode layer; Step 4: preparing a tunneling layer on the surface of the N-type base doping layer; Step 5: preparing a hole transport layer on the surface of the tunneling layer; Step 6: preparing a perovskite absorption layer on the surface of the hole transport layer; Step 7: preparing a passivation layer on the surface of the perovskite absorption layer; Step 8: preparing an electron transport layer on the surface of the passivation layer; Step nine: preparing a buffer layer on the surface of the electron transport layer; Step ten: preparing a second transparent electrode layer on the surface of the buffer layer; Step 11: preparing a second metal electrode layer on the surface of the second transparent electrode layer; Step 12: preparing an anti-reflection layer on the surface of the second metal electrode layer.

10. The method for preparing a stacked solar cell according to claim 9, characterized in that: In step 2, the substrate sample of step 1 is placed in a magnetron sputtering device by magnetron sputtering method, an ITO target is set, the power is controlled to 60 W, and the operation time is 1.5 h.

11. The method for preparing a stacked solar cell according to claim 9, characterized in that: In step 3, the substrate sample in step 2 is placed on the mask plate by evaporation method and placed in the chamber of the evaporation machine until the evaporation vacuum degree is 2×10 -4 Pa, the evaporation voltage and evaporation temperature were adjusted, the evaporation rate was controlled at 2.5Å / S, and silver was evaporated onto the film.

12. The method for preparing a stacked solar cell according to claim 9, characterized in that: In step 4, the substrate sample in step 3 is placed on the mask by magnetron sputtering, and placed in the magnetron sputtering equipment with a control power of 60 W and a running time of 1 hour.

13. The method for preparing a stacked solar cell according to claim 9, characterized in that: In step five, the hole transport layer dispersion is evenly coated on the surface of the substrate sample in step four by spin coating, and the spin coating speed is set to 2000 rpm, the spin coating time is 40 s, and the solution volume is 100 ul; after the spin coating is completed, annealing operation is performed, the annealing temperature is 450°C, and the annealing time is 30 min.

14. The method for preparing a stacked solar cell according to claim 9, characterized in that: In step 7, the substrate sample in step 6 is placed on the mask plate by evaporation method and placed in the chamber of the evaporation machine until the evaporation vacuum degree is 2×10 -4 Pa, the evaporation voltage was adjusted to the evaporation temperature, the evaporation rate was controlled at 0.1Å / S, and propylenediamine iodine was evaporated onto the layer film; after the evaporation was completed, annealing was performed, the annealing temperature was 100°C, and the annealing time was 8min.

15. The method for preparing a stacked solar cell according to claim 9, characterized in that: In step eight, the substrate sample in step seven is placed on the mask plate by evaporation, and placed in the chamber of the evaporation machine until the evaporation vacuum degree is 1×10 -4 Pa, the evaporation voltage was adjusted to the evaporation temperature, the evaporation rate was controlled at 0.1-0.15Å / S, and C60 was evaporated onto the film.

16. The method for preparing a stacked solar cell according to claim 9, characterized in that: In step nine, SnO2 is deposited onto the film by atomic deposition, and the vacuum degree of the atomic deposition equipment is set to 0.5×10 -4 Pa, the deposition pipe temperature is 60 °C, and the deposition chamber temperature is 70 °C.

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