A perovskite solar cell and its preparation method

Abstract

The present invention discloses a perovskite solar cell and a preparation method thereof, comprising a perovskite light absorbing layer, wherein the perovskite light absorbing layer is formed by annealing a perovskite thin film and then performing a hot pressing treatment, and the grain size of the perovskite light absorbing layer is 800nm ​​to 1000nm; the preparation method comprises the steps of preparing the perovskite light absorbing layer, wherein the steps of preparing the perovskite light absorbing layer comprise: preparing a perovskite thin film; annealing the perovskite thin film; and hot pressing the annealed perovskite thin film to obtain the perovskite light absorbing layer. In the perovskite solar cell provided by the present invention, the hot-pressed perovskite light absorbing layer has the advantages of large grain size, uniform grain size, and high density between grains, and can improve the electrical performance of the perovskite solar cell.

Description

Technical Field

[0001] The present invention relates to the technical field of perovskite solar cells, and in particular to a perovskite solar cell and a preparation method thereof. Background Art

[0002] Photovoltaic technology, which uses solar panels to convert light into electricity, is considered the most efficient method for large-scale solar energy utilization. Since the advent of the first solar cell, photovoltaic technology has continued to achieve breakthroughs. After rapid development in recent years, perovskite solar cells, a third-generation solar cell, have garnered widespread international attention due to their numerous advantages, becoming a rising star in the optoelectronics and materials fields. Initially, perovskite materials were applied to batteries, achieving an efficiency of only 3.8%. Subsequently, researchers optimized perovskite solar cells from various aspects, including materials and interfaces, achieving a photoelectric efficiency exceeding 15%. Currently, laboratory efficiency of perovskite cells has reached 25.5%.

[0003] Although the photoelectric conversion efficiency of perovskite solar cells has been continuously improved, the problem of unstable perovskite structure is still very prominent. The surface uniformity of perovskite films produced by solvent method is poor, the grain size is small and varies greatly, so there are a lot of gaps at the contact between the grains, and there are many defects on the surface of the perovskite film, which seriously affects the performance of the device. To solve this problem, researchers usually add some additives to passivate the perovskite surface, which can reduce defects to a certain extent. However, these additives are often high-cost substances such as fullerene derivatives, which further limits the commercialization process of perovskite solar cells. In the traditional continuous annealing process, the growth of grains is uncontrollable, so the perovskite grain size is small, the grain growth is uneven, the grains are not dense, and there are even perforations in the perovskite film. Summary of the Invention

[0004] In view of this, the present invention provides a perovskite solar cell and a preparation method thereof to solve the problems in the existing continuous annealing process, such as small perovskite grain size, uneven grain size, and insufficient density between grains, which are not conducive to the performance improvement and stability of perovskite solar cells.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention first provides a perovskite solar cell, comprising a perovskite light absorption layer, wherein the perovskite light absorption layer is formed by annealing a perovskite thin film and then performing a hot pressing treatment, and the grain size of the perovskite light absorption layer is 800nm ​​to 1000nm.

[0007] Preferably, the perovskite solar cell further comprises a conductive substrate, a first charge transport layer, a second charge transport layer and a conductive electrode layer;

[0008] The first charge transport layer is arranged on the conductive substrate, the perovskite light absorption layer is arranged on the first charge transport layer, the second charge transport layer is arranged on the perovskite light absorption layer, and the conductive electrode layer is arranged on the second charge transport layer.

[0009] Preferably, the perovskite light absorbing layer has a thickness of 300 nm to 600 nm.

[0010] Preferably, the first charge transport layer is a hole transport layer, and the second charge transport layer is an electron transport layer; or, the first charge transport layer is an electron transport layer, and the second charge transport layer is a hole transport layer.

[0011] Preferably, the thickness of the electron transport layer is 5 nm to 20 nm, the thickness of the hole transport layer is 5 nm to 100 nm, and the thickness of the conductive electrode layer is 70 nm to 400 nm.

[0012] The present invention also provides a method for preparing the perovskite solar cell as described above, comprising the steps of preparing a perovskite light absorbing layer, wherein the steps of preparing the perovskite light absorbing layer comprise:

[0013] S101, preparing and forming a perovskite film;

[0014] S102, performing annealing treatment on the perovskite film;

[0015] S103 , performing hot pressing on the annealed perovskite film to obtain the perovskite light absorbing layer.

[0016] Specifically, in step S103, before performing the hot pressing treatment on the perovskite light absorbing layer, a hot pressing protective film is provided on the perovskite thin film after the annealing treatment.

[0017] Preferably, the material of the hot pressing protective film is a hydrophobic material.

[0018] Specifically, the hot pressing treatment is mechanical hot pressing treatment or warm hot pressing treatment, the pressure in the hot pressing treatment is 10 MPa to 300 MPa, the temperature is 70° C. to 190° C., and the hot pressing treatment time is 10 min to 40 min.

[0019] Specifically, the preparation method comprises the following steps:

[0020] S10, providing the conductive substrate, and preparing a first charge transport layer on the conductive substrate;

[0021] S20, preparing a perovskite light absorption layer on the first charge transport layer;

[0022] S30, preparing a second charge transport layer on the perovskite light absorption layer;

[0023] S40, preparing a conductive electrode layer on the second charge transport layer.

[0024] Compared with the prior art, the perovskite solar cell and the preparation method thereof provided in the embodiments of the present invention perform annealing treatment on the prepared perovskite film, and perform hot pressing treatment on the annealed perovskite film to obtain a perovskite light absorption layer. The hot-pressed perovskite light absorption layer has the advantages of large grain size, uniform grain size, and high density between grains, which can improve the electrical performance of the perovskite solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the structure of a perovskite solar cell provided by an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the preparation process of a perovskite solar cell provided by an embodiment of the present invention;

[0027] Figure 3a and Figure 3b is a microscopic diagram of ions performing heat treatment on a perovskite light absorbing layer according to an embodiment of the present invention;

[0028] Figure 4 is a diagram of the water wetting angle of the PDMS hot-pressed protective film in an embodiment of the present invention;

[0029] Figure 5 is an AFM image of a PDMS protective film covering a perovskite thin film layer in an embodiment of the present invention;

[0030] Figures 6a-6c This is a SEM image of the perovskite light absorption layer under an electron microscope at a magnification of 80,000 times in an embodiment of the present invention;

[0031] Figure 7 This is a SEM image of the perovskite light absorption layer under an electron microscope at a magnification of 10,000 times in an embodiment of the present invention;

[0032] Figure 8 is the XRD pattern of the perovskite light absorbing layer in an embodiment of the present invention;

[0033] Figure 9 4 is a current density-voltage curve diagram of a perovskite solar cell provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] To make the objectives, technical solutions, and advantages of the present invention more apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. Examples of these preferred embodiments are illustrated in the accompanying drawings. The embodiments of the present invention shown in and described with reference to the accompanying drawings are merely exemplary, and the present invention is not limited to these embodiments.

[0035] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, the accompanying drawings only show structures and / or processing steps closely related to the solutions according to the present invention, while other details that are not closely related to the present invention are omitted.

[0036] The embodiment of the present invention first provides a perovskite solar cell, such as Figure 1 As shown, the perovskite solar cell includes a conductive substrate 1, a first charge transport layer 2, a perovskite light absorption layer 3, a second charge transport layer 4 and a conductive electrode layer 5.

[0037] Among them, the first charge transport layer 2 is arranged on the conductive substrate 1, the perovskite light absorption layer 3 is arranged on the first charge transport layer 2, the second charge transport layer 4 is arranged on the perovskite light absorption layer 3, and the conductive electrode layer 5 is arranged on the second charge transport layer 4.

[0038] The perovskite light absorbing layer 3 is formed by annealing a perovskite thin film and then performing a hot pressing process. The perovskite light absorbing layer 3 has a relatively large grain size, which is 800 nm to 1000 nm.

[0039] Specifically, the perovskite light absorbing layer 3 has an ABX3 structure, where A is CH3NH3 + or CH(NH2)2 + or Cs + , B is Pb 2+ or Sn 2+ , X is Cl - or Br - or I - .

[0040] In the perovskite solar cell provided in the above embodiment, the perovskite light absorption layer subjected to heat pressing treatment has the advantages of large grain size, uniform grain size, and high density between grains, which can improve the electrical performance of the perovskite solar cell.

[0041] In a preferred embodiment, the first charge transport layer 2 is a hole transport layer, and the second charge transport layer 4 is an electron transport layer; or, the first charge transport layer 2 is an electron transport layer, and the second charge transport layer 4 is a hole transport layer.

[0042] In a preferred embodiment, the thickness of the electron transport layer can be set to 5nm~20nm, for example, 5nm, 6nm, 8nm, 10nm, 12nm, 15nm, 18nm, or 20nm; the thickness of the perovskite light absorption layer can be set to 300nm~600nm, for example, 350nm, 400nm, 460nm, 500nm, 550nm or 600nm; the thickness of the hole transport layer can be set to 5nm~100nm, for example, 5nm, 10nm, 20nm, 30nm, 50nm or 100nm; the thickness of the conductive electrode layer can be set to 70nm~400nm, for example, 70nm, 100nm, 200nm, 250nm, 350nm or 400nm.

[0043] The present invention also provides a method for preparing the perovskite solar cell as described above. Figure 2 and combined Figure 1 , the preparation method comprises the following steps:

[0044] S10, such as Figure 2 As shown in (a), a conductive substrate 1 is provided, and the first charge transport layer 2 is prepared on the conductive substrate 1.

[0045] S20, preparing the perovskite light absorption layer 3 on the first charge transport layer 2.

[0046] Specifically, step S20 includes:

[0047] S101、 Figure 2 As shown in (b), the perovskite film 3a is first formed on the first charge transport layer 2.

[0048] S102, such as Figure 2 As shown in (c), the perovskite film 3a is annealed to obtain a perovskite film 3b. Referring to existing technical solutions, the perovskite film 3a is annealed to crystallize the perovskite film, thereby obtaining an annealed perovskite film 3b. In a preferred embodiment, the annealing process is a constant temperature annealing process.

[0049] S103, such as Figure 2 As shown in 2-(d) and 2-(e), the perovskite thin film 3b after annealing is subjected to hot pressing to obtain the perovskite light absorbing layer 3.

[0050] In a preferred embodiment, before the perovskite film 3 b is subjected to the hot pressing treatment, the hot pressing protective film 6 is firstly provided on the annealed perovskite film 3 b.

[0051] In a preferred solution, the material of the hot pressing protective film 6 is a hydrophobic material.

[0052] In a specific embodiment, the material of the hot pressing protective film 6 is preferably PDMS (polydimethylsiloxane), and the preparation method of the hot pressing protective film 6 is: the basic components of the PDMS precursor and the curing agent are uniformly mixed and stirred to obtain a viscous mixture, and the viscous mixture is coated on the perovskite film 3b using a coating process, and then heated and cured, thereby preparing a PDMS hot pressing protective film 6 on the perovskite film 3b.

[0053] Specifically, the hot pressing treatment is mechanical hot pressing treatment or warm hot pressing treatment, such as Figure 2 In (d), R represents mechanical hot pressing or isotropic hot pressing. In the hot pressing, the pressure is 10 MPa to 300 MPa, for example, 10 MPa, 20 MPa, 50 MPa, 80 MPa, 100 MPa, 150 MPa, 180 MPa, 200 MPa, 250 MPa, or 300 MPa; the temperature can be 70° C. to 190° C., for example, 70° C., 80° C., 100° C., 120° C., 150° C., 180° C., or 190° C.; and the hot pressing time is 10 min to 40 min, for example, 10 min, 20 min, 30 min, or 40 min.

[0054] Specifically, the hot pressing treatment can be performed in an inert gas environment such as nitrogen, argon, etc., or in an air environment with low humidity.

[0055] Specifically, when the warm isotropic hot pressing treatment is selected and the medium in the warm isotropic hot pressing treatment is liquid, the sample obtained by preparing the hot pressing protective film 6 is first vacuum-wrapped and then hot pressed.

[0056] S30, such as Figure 2 -As shown in (f), the second charge transport layer 4 is prepared on the perovskite light absorption layer 3.

[0057] S40, such as Figure 2 As shown in (f), the conductive electrode layer 5 is prepared on the second charge transport layer 4.

[0058] Specifically, a metal film is deposited on the second charge transport layer 4 by evaporation or vapor deposition to obtain the conductive electrode layer 5. The metal is, for example, Ag, Cu, Al or Au.

[0059] Specifically, in the process of preparing the first charge transport layer 2 and the second charge transport layer 4, the hole transport layer can be prepared by spin coating, thermal evaporation, magnetron sputtering or spray pyrolysis, and the electron transport layer can be prepared by spin coating or thermal evaporation.

[0060] Example 1

[0061] This embodiment provides a perovskite solar cell, the preparation method of which includes the following process steps:

[0062] (1) FTO glass is selected as the material of the conductive substrate, wherein the FTO glass is ultrasonically cleaned in sequence with glass cleaning agent, deionized water, industrial alcohol and anhydrous ethanol for 20 minutes to prepare the conductive substrate.

[0063] (2) A NiO hole transport layer was prepared on the FTO glass surface by spray pyrolysis, with a NiO concentration of 10 mg / ml. After spraying, the hole transport layer was annealed at 570°C.

[0064] (3) A perovskite film was prepared on the hole transport layer by a one-step spin coating method to obtain a perovskite light absorption layer. The perovskite film was subjected to a constant temperature annealing treatment at a temperature of 105°C and an annealing time of 15 minutes. The thickness of the perovskite light absorption layer was 400 nm. The perovskite material used in this embodiment is FA 0.85 Cs 0.15 PbI 2.85 Br 0.15 .

[0065] (4) An electron transport layer made of PCBM is prepared by spin coating on the perovskite light absorption layer, wherein the thickness of the electron transport layer is 20 nm.

[0066] (5) The above samples are sent to a vacuum thermal evaporation device, and a metal electrode is evaporated on the electron transport layer to obtain the conductive electrode layer. The metal electrode is Ag, and the thickness of the metal electrode is 80 nm.

[0067] Based on the above preparation process steps, this embodiment prepared a perovskite solar cell sample 1.

[0068] Example 2

[0069] Compared with Example 1, Example 2 differs in that: in step (3), the perovskite thin film after constant temperature annealing is subjected to a secondary high-temperature heat treatment to prepare the perovskite light absorbing layer; wherein the temperature of the secondary high-temperature heat treatment is 160° C. and the time is 15 minutes. The remaining preparation process steps of Example 2 are the same as those of Example 1.

[0070] Based on the above preparation process steps, this embodiment prepared a perovskite solar cell sample 2.

[0071] Example 3

[0072] Compared with Example 1, the difference of Example 3 is that: in step (3), the perovskite film after constant temperature annealing is subjected to mechanical hot pressing treatment, thereby preparing the perovskite light absorption layer.

[0073] The specific process of mechanical hot pressing treatment is: the basic components of the PDMS precursor and the curing agent are evenly mixed and stirred in a volume ratio of 10:1 to obtain a viscous mixture, which is then coated on the perovskite film after constant temperature annealing by a coating process, and then heated and cured to form a hot pressing protective film. After the PDMS hot pressing protective film is prepared, a mechanical hot pressing treatment is performed, wherein the pressure is set to 30MPa, the hot pressing temperature is set to 160°C, and the hot pressing time is 15min. After the hot pressing is completed, the PDMS hot pressing protective film is peeled off, thereby preparing the perovskite light absorption layer. The remaining preparation process steps of Example 3 are the same as those of Example 1.

[0074] Based on the above preparation process steps, this embodiment prepared a perovskite solar cell sample 3.

[0075] Example 4

[0076] Compared with Example 3, Example 4 differs in that: in step (3), the process for hot pressing the perovskite film after constant temperature annealing is selected as a warm isostatic hot pressing process, wherein the hot pressing pressure is set to 30 MPa, the hot pressing temperature is set to 160°C, and the hot pressing time is 15 minutes. The remaining preparation process steps of Example 4 are the same as those of Example 3, that is, the same as those of Example 1.

[0077] Based on the above preparation process steps, this embodiment prepared a perovskite solar cell sample 4.

[0078] It should be noted that in the above embodiments 1-4: Embodiment 1 is based on the existing technical solution and only performs annealing treatment when preparing the perovskite light absorbing layer; Embodiment 2 is based on the technical solution proposed in the present invention and then performs a secondary high-temperature heat treatment after annealing treatment when preparing the perovskite light absorbing layer to increase the grain size of the perovskite light absorbing layer; Embodiments 3 and 4 are based on the technical solution proposed in the present invention and then perform hot pressing treatment after annealing treatment when preparing the perovskite light absorbing layer to increase the grain size of the perovskite light absorbing layer.

[0079] The perovskite solar cell samples 1-4 prepared in the above examples 1-4 were tested under standard conditions, i.e., AM1.5, 100 mW / cm 2 Conditions, the test data in Table 1 below are obtained.

[0080] Table 1:

[0081] Example Voc(V) <![CDATA[Jsc(mA / cm -2 )]]> FF(%) <![CDATA[E ff (%)]]> Example 1 Sample 1 1.063 22.799 81.313 19.704 Example 2 Sample 2 0.813 17.385 29.523 4.172 Example 3 Sample 3 1.133 23.013 78.024 20.347 Example 4 Sample 4 1.116 23.211 79.266 20.524

[0082] From the data in Table 1, it can be seen that in Example 2, the fill factor of the cell dropped sharply by the secondary high-temperature treatment of the perovskite film, which reduced the electrical performance of the cell. However, in Example 3 and Example 4, the current density (Jsc), voltage (Voc) and efficiency (E) of the perovskite solar cell were improved by the mechanical hot pressing process and the warm isotropic hot pressing process. ff ).

[0083] In order to increase the grain size of the perovskite light absorbing layer, the solution of Example 2 is to perform a secondary high-temperature heat treatment, while Examples 3 and 4 are to perform a hot pressing treatment. The two treatment methods have completely different effects on the perovskite solar cell. The applicant further studied and found that: Figure 3a As shown in FIG, after the secondary high-temperature heat treatment, the perovskite material (ABX3) will be thermally decomposed, and the organic cation (A) therein will leave the perovskite film, resulting in the deterioration of the performance of the final absorption layer; as shown in FIG. Figure 3b As shown, in the solution of the present invention, a hot pressing treatment is adopted. First, the high temperature condition can make the perovskite grains grow again, and the perovskite grains are denser; and the pressure effect inhibits the thermal decomposition of the perovskite material during the high temperature process, prevents the precipitation of halogen compounds, and the hot pressing protective film can prevent organic cations from leaving the perovskite film during the hot pressing process, thereby obtaining a higher quality perovskite light absorption layer, which can improve the electrical performance of the perovskite solar cell.

[0084] Figure 4 This is a diagram of the water wetting angle of the PDMS hot press protective film used in Example 3 and Example 4. Figure 4 It can be seen that the PDMS hot pressing protective film has a hydrophobic and non-stick surface. Therefore, after the hot pressing treatment is completed, when the PDMS hot pressing protective film is peeled off from the perovskite light absorption layer, the PDMS hot pressing protective film will not leave any residue on the perovskite light absorption layer. At the same time, the PMDS film has high chemical inertness, and the entire hot pressing process will not have an adverse effect on the perovskite light absorption layer.

[0085] Figure 5 The atomic force microscope (AFM) images of the PDMS film covering the perovskite film layer in Examples 3 and 4 are shown. Figure 5 It can be seen that the PDMS membrane has low roughness, with a roughness Ra value below 2, indicating that the PDMS membrane is very flat and can ensure equal forces and pressures in all directions during the hot pressing process.

[0086] Figures 6a-6c This is a scanning electron microscope (SEM) image of the perovskite light absorption layer under an electron microscope magnified 80,000 times. Figure 6a is a SEM image of the perovskite light absorbing layer obtained by mechanical hot pressing in Example 3; Figure 6b is an SEM image of the perovskite light absorbing layer obtained by warm isotropic hot pressing in Example 4; Figure 6c This is the SEM image of the perovskite light absorption layer obtained by only applying constant temperature annealing treatment to the perovskite film in Example 1. Figures 6a-6c By comparison, it can be seen that after mechanical hot pressing or warm isotropic hot pressing treatment of the perovskite film, the perovskite grains can grow again, the size of the perovskite grains can be increased, the grain size of the perovskite light absorption layer can reach more than 800nm, and the grains of the perovskite light absorption layer are denser.

[0087] Figure 7 This is a SEM image of the perovskite light absorption layer under a 10,000x electron microscope. Figure 7 -(a) is an SEM image of the perovskite light absorption layer treated with constant temperature annealing in Example 1; Figure 7 -(b) is an SEM image of the perovskite light absorption layer after secondary high-temperature heat treatment in Example 2; Figure 7 -(c) is an SEM image of the perovskite light absorbing layer after mechanical hot pressing treatment in Example 3; 7-(d) is an SEM image of the perovskite light absorbing layer after warm isostatic hot pressing treatment in Example 4. By comparison, it can be seen that the simple secondary high-temperature heat treatment used in Example 2 will accelerate grain growth, but at the same time it will accelerate the decomposition of the perovskite, prompting organic cations to leave the perovskite layer, and a large amount of PbI2 will precipitate on the surface of the perovskite. The mechanical hot pressing treatment and warm isostatic hot pressing treatment in Examples 3 and 4 will inhibit the decomposition of the perovskite while promoting grain growth. There is no large amount of PbI2 precipitation on the surface of the perovskite layer, which proves that the hot pressing process is different from the ordinary secondary high-temperature heat treatment and is more reliable.

[0088] Figure 8 is the X-ray diffraction (XRD) diagram of the perovskite light absorbing layer of Example 1 and Example 2. Figure 8 It can be seen that the peak intensity of PbI2 and perovskite 100 phase in the perovskite is enhanced after the secondary high-temperature heat treatment in Example 2, indicating that the growth of perovskite grains and the large-scale decomposition of PbI2 occur simultaneously. Therefore, the secondary high-temperature heat treatment of the perovskite film after constant temperature annealing cannot make the perovskite grains grow while ensuring that the perovskite is not decomposed.

[0089] Figure 9 The current density voltage curve of the perovskite solar cell samples prepared in Examples 1-4 is shown in FIG. Figure 9 It can be seen that Example 2 adopts secondary high-temperature heat treatment of the perovskite film, and the current density and voltage of the perovskite solar cell prepared are greatly reduced, which seriously affects the performance of the battery. In Example 3 and Example 4, the current density and voltage of the perovskite solar cell prepared by mechanical hot pressing or warm hot pressing of the perovskite film are improved compared with Example 1.

[0090] In summary, the technical solution provided by the present invention effectively improves the flatness of the perovskite film through the dual effects of strong pressure and high temperature, making the perovskite grains more uniform, larger in size, with fewer defects and reduced film roughness. During mechanical pressure or warm isostatic pressing, the pressure suppresses the thermal decomposition of the perovskite during the annealing process. Therefore, only crystals grow in this process without thermal decomposition. The perovskite film has better crystallinity, crystal density and good lattice orientation, thereby improving the electrical performance of the perovskite solar cell. The preparation process of the present invention is simple to operate, low in cost, and conducive to large-scale promotion.

[0091] The above is only a specific implementation method of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for preparing a perovskite solar cell, comprising the steps of preparing a perovskite light absorbing layer, characterized in that: The steps of preparing the perovskite light absorbing layer include: S101, preparing and forming a perovskite film; S102, performing annealing treatment on the perovskite film; S103, performing hot pressing on the annealed perovskite film to obtain the perovskite light absorbing layer, wherein the grain size of the perovskite light absorbing layer is 800 nm to 1000 nm; Among them, the step S103 specifically includes: uniformly mixing the basic components of the PDMS precursor and the curing agent in a volume ratio of 10:1 to obtain a viscous mixture; then using a coating process to coat the viscous mixture on the annealed perovskite film, and heating and curing to form a hot pressing protective film; performing mechanical hot pressing treatment or warm hot pressing treatment under the conditions of a pressure of 10MPa to 300MPa, a temperature of 70°C to 190°C, and a hot pressing treatment time of 10min to 40min; after completing the hot pressing treatment, peeling off the hot pressing protective film to obtain the perovskite light absorption layer.

2. The method for preparing a perovskite solar cell according to claim 1, wherein: The material of the hot pressing protective film is a hydrophobic material.

3. The method for preparing a perovskite solar cell according to claim 1 or 2, wherein: The preparation method comprises the following steps: S10, providing a conductive substrate, and preparing a first charge transport layer on the conductive substrate; S20, preparing a perovskite light absorption layer on the first charge transport layer; S30, preparing a second charge transport layer on the perovskite light absorption layer; S40, preparing a conductive electrode layer on the second charge transport layer.

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