Method for preparing passivation layer, and crystalline silicon / perovskite tandem solar cell

Abstract

A method for preparing a passivation layer, and a crystalline silicon / perovskite tandem solar cell. The method for preparing a passivation layer comprises a crystalline silicon cell (1) and a perovskite cell (2); the perovskite cell (2) comprises a hole transport layer (21) arranged on the surface of the crystalline silicon cell (1), a perovskite absorption layer (22) arranged on the surface of the hole transport layer (21), a top passivation layer (23) arranged on the surface of the perovskite absorption layer (22), an electron transport layer (24) arranged on the surface of the top passivation layer (23), and a top electrode layer (26) arranged on the surface of the electron transport layer (24); and the crystalline silicon cell (1), the hole transport layer (21), and the perovskite absorption layer (22) are combined to form a stable thin-film substrate. The stable thin-film substrate is excited by means of illumination to form a metastable thin-film substrate.

Description

A method for preparing a passivation layer and a crystalline silicon / perovskite tandem solar cell

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on July 8, 2023, with application number 202310832551.3, and invention name “A method for preparing a passivation layer and crystalline silicon / perovskite stacked solar cell”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of solar cells, and in particular to a method for preparing a passivation layer, and a crystalline silicon / perovskite stacked solar cell prepared by the method for preparing a passivation layer. 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 relatively mature industrial technologies for single-crystal silicon and polycrystalline silicon solar cells are already available. In recent years, crystalline silicon / perovskite 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 crystalline silicon / perovskite 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, along with the stability and excellent electron transport properties of the crystalline silicon material, to improve the photoelectric conversion efficiency of solar cells.

[0005] Currently, the photovoltaic conversion efficiency of crystalline silicon / perovskite tandem solar cells has exceeded 32%. Although this is still below the theoretical value, there is still significant room for improvement, and stability issues are also a challenge that needs to be addressed. Optimizing the perovskite absorber layer is a key focus of crystalline silicon / perovskite tandem solar cells. This perovskite absorber layer is prone to surface or interface defects, causing a large amount of non-radiative recombination, which leads to a decrease in the photovoltaic and stability performance of the cell device. In the specific wide-bandgap perovskite absorber layer required for crystalline silicon / perovskite tandem solar cells, its unique photoinduced phase separation phenomenon also causes more defects in the film, thereby affecting efficiency and stability.

[0006] While many effective methods for interface passivation exist, most are ineffective at sites within the film where defects are potentially present. Furthermore, in crystalline silicon / perovskite tandem solar cells, the required perovskite film is a wide-bandgap perovskite with a bandgap of 1.68-1.73 eV, which exhibits photoinduced phase separation and is more susceptible to the formation of new defects under illumination. Common passivation methods treat stable perovskite films stored in the dark. These methods are effective in passivating existing defects in the stable state of wide-bandgap perovskite films.

[0007] However, the normal working condition of photovoltaic devices is 1000mW / cm2 under AM1.5G 2 The research was conducted under 1-sun illumination. Under normal operating conditions, the perovskite film is in a metastable state excited by light, which generates new defects. Common passivation methods are ineffective against these newly generated defects in metastable perovskite films under illumination, making it difficult to further improve the photoelectric conversion efficiency and stability of crystalline silicon / perovskite tandem solar cells. Application Contents

[0008] The purpose of the embodiments of the present application is to provide a method for preparing a passivation layer and a crystalline silicon / perovskite tandem solar cell, including but not limited to solving the problem that new defects are easily generated in metastable perovskite films under light conditions, thereby affecting the photoelectric conversion efficiency and stability of the crystalline silicon / perovskite tandem solar cell.

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

[0010] In a first aspect, a method for preparing a passivation layer is provided, comprising a crystalline silicon cell and a perovskite cell disposed above the crystalline silicon cell, wherein the perovskite cell comprises a hole transport layer disposed on a surface of the crystalline silicon cell, a perovskite absorption layer disposed on a surface of the hole transport layer, a top passivation layer disposed on a surface of the perovskite absorption layer, an electron transport layer disposed on a surface of the top passivation layer, and a top electrode layer disposed on a surface of the electron transport layer; the crystalline silicon cell, the hole transport layer, and the perovskite absorption layer are combined to form a stable thin film substrate;

[0011] The stable thin film substrate is excited by light to form a metastable thin film substrate; and the top passivation layer is formed on the surface of the metastable thin film substrate under continuous light irradiation.

[0012] In one embodiment, the steps include:

[0013] preparing a passivation layer dispersion, and uniformly coating the passivation layer dispersion on the surface of the perovskite absorption layer;

[0014] dissolving propylenediamine iodide in an organic solvent and performing ultrasonic dissolution, and spin-coating the dissolved solution on the surface of the perovskite absorption layer;

[0015] After the spin coating is completed, an annealing process is performed to form the top passivation layer.

[0016] In one embodiment, the steps include:

[0017] preparing a passivation layer dispersion, and spraying the passivation layer dispersion on the surface of the perovskite absorption layer;

[0018] After the spraying is completed, an annealing process is performed to form the top passivation layer.

[0019] In one embodiment, the top passivation layer includes at least one of propylenediamine bromide, butylammonium chloride, butylammonium bromide, butylammonium iodide, N,N-dimethyl-1,3-propylenediamine hydrochloride, and dodecanediamine bromide.

[0020] In one embodiment, the top passivation layer includes at least one of magnesium fluoride, lithium fluoride, and sodium fluoride.

[0021] In one embodiment, the steps include:

[0022] preparing a perovskite precursor solution, and uniformly coating the perovskite precursor solution on the surface of the hole transport layer;

[0023] Dynamic spin coating using antisolvent;

[0024] After the spin coating is completed, an annealing treatment is performed to form the perovskite absorption layer; or after the spin coating is completed, a flash evaporation treatment is performed, and after the flash evaporation is completed, an annealing treatment is performed to form the perovskite absorption layer.

[0025] In one embodiment, the perovskite precursor solution is prepared by dissolving ABX3 structured perovskite in an organic solvent, and the concentration of the perovskite precursor solution is in the range of 1.5-2M.

[0026] In one embodiment, in the ABX3 structure perovskite: the A position is an organic cation, including CH3NH3 + (MA+), NH2CH=NH2 + (FA+), CH3CH2NH3 + or Cs + At least one of; B position is a metal cation, including Pb 2+ 、Sn 2+ At least one of; X is a halogen anion, including F - 、Cl - Br - , I - At least one of .

[0027] In one embodiment, the method includes the steps of preparing perovskite precursor powder and evaporating the perovskite precursor powder onto the surface of the hole transport layer.

[0028] In one embodiment, the crystalline silicon cell includes a first metal electrode layer, a first transparent electrode layer provided on the first metal electrode layer, a P-type base doping layer provided on the first transparent electrode layer, a base bottom surface passivation layer provided on the P-type base doping layer, a substrate provided on the base bottom surface passivation layer, a base surface passivation layer provided on the substrate, an N-type base doping layer provided on the base surface passivation layer, and a tunneling layer provided on the N-type base doping layer.

[0029] In one embodiment, the top electrode layer includes a second transparent electrode layer and a second metal electrode layer disposed on a surface of the second transparent electrode layer.

[0030] In one embodiment, the perovskite cell further includes a buffer layer disposed between the electron transport layer and the top electrode layer.

[0031] In one embodiment, the buffer layer is at least one of zinc oxide (ZnO), tin dioxide (SnO2), and titanium dioxide (TiO2).

[0032] In one embodiment, the perovskite cell further includes an anti-reflection layer disposed on a surface of the top electrode layer.

[0033] In one embodiment, the anti-reflection layer is at least one of magnesium fluoride, lithium fluoride (LiF), sodium fluoride (NaF), and silicon oxide (SiO2).

[0034] In one embodiment, the hole transport layer is at least one of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly-3-hexylthiophene (P3HT), nickel oxide (NiOx), molybdenum trioxide (MoO3), cuprous iodide (CuI), and cuprous thiocyanate (CuSCN).

[0035] In one embodiment, the electron transport layer is zinc oxide (ZnO), tin dioxide (SnO2), titanium dioxide (TiO2), [6,6]-phenyl C61 butyric acid methyl ester (PC 61 BM), carbon 60 (C 60 ), at least one of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP).

[0036] In a second aspect, a crystalline silicon / perovskite tandem solar cell is provided, which is prepared using the method for preparing a passivation layer provided in any of the above embodiments.

[0037] The beneficial effect of the method for preparing a passivation layer provided in the embodiments of the present application is that: by pre-exciting the stable thin film substrate through light exposure to form a metastable thin film substrate, it not only passivates existing defects in the stable thin film substrate, but also passivates sites where defects may arise in the perovskite under light exposure, thus overcoming new defects generated in the metastable perovskite film under light exposure and further improving the passivation effect. This method can also effectively suppress the photoinduced phase separation phenomenon of wide-bandgap perovskites, improving the photoelectric conversion efficiency and stability of crystalline silicon / perovskite tandem solar cells.

[0038] The beneficial effect of the crystalline silicon / perovskite tandem solar cell provided in the embodiment of the present application is that the crystalline silicon / perovskite tandem solar cell prepared by the above method has high photoelectric conversion efficiency and good stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] 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.

[0040] FIG1 is a schematic structural diagram of a crystalline silicon / perovskite tandem solar cell provided in an embodiment of the present application;

[0041] FIG2 is a schematic structural diagram of a stable thin film substrate in step seven provided in an embodiment of the present application;

[0042] FIG3 is a schematic structural diagram of the method of exciting a stable thin film substrate to a metastable thin film substrate by light in step seven according to an embodiment of the present application;

[0043] FIG4 is a schematic structural diagram of a stable thin film substrate with a top passivation layer obtained in step seven according to an embodiment of the present application.

[0044] Among them, the main marks of the drawings in the figure are:

[0045] 1. Crystalline silicon cell; 11. First metal electrode layer; 12. First transparent electrode layer; 13. P-type base doping layer; 14. Base bottom passivation layer; 15. Substrate; 16. Base surface passivation layer; 17. N-type base doping layer; 18. Tunneling layer;

[0046] 2. Perovskite cell; 21. Hole transport layer; 22. Perovskite absorption layer; 23. Top passivation layer; 24. Electron transport layer; 25. Buffer layer; 26. Top electrode layer; 261. Second transparent electrode layer; 262. Second metal electrode layer; 27. Anti-reflection layer. DETAILED DESCRIPTION

[0047] 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.

[0048] 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.

[0049] In order to illustrate the technical solution provided by this application, a detailed description is given below with reference to specific drawings and embodiments.

[0050] Referring to FIG1 , the method for preparing a passivation layer provided in an embodiment of the present application will now be described. The method for preparing a passivation layer includes a crystalline silicon cell 1 and a perovskite cell 2 disposed above the crystalline silicon cell 1. Optionally, the perovskite cell 2 includes a hole transport layer 21 disposed on the surface of the crystalline silicon cell 1, a perovskite absorber layer 22 disposed on the surface of the hole transport layer 21, a top passivation layer 23 disposed on the surface of the perovskite absorber layer 22, an electron transport layer 24 disposed on the surface of the top passivation layer 23, and a top electrode layer 26 disposed on the surface of the electron transport layer 24. The crystalline silicon cell 1, the hole transport layer 21, and the perovskite absorber layer 22 are combined to form a stable thin film substrate. During the preparation of the top passivation layer 23, the stable thin film substrate is excited by light to form a metastable thin film substrate. Under continuous light irradiation, the top passivation layer 23 is formed on the surface of the metastable thin film substrate (which can be understood as the surface of the perovskite absorber layer 22).

[0051] This structure, in the present application, pre-excites the stable thin film substrate through light to form a metastable thin film substrate, which can not only passivate the defects already existing in the stable thin film substrate, but also passivate the sites where defects may be generated in the perovskite under light conditions, that is, it overcomes the new defects generated in the metastable perovskite film under light conditions and can further improve the passivation effect.

[0052] The present application also provides a crystalline silicon / perovskite tandem solar cell, which is prepared using the method for preparing a passivation layer. Specifically, the crystalline silicon / perovskite tandem solar cell includes a crystalline silicon cell 1 and a perovskite cell 2 disposed above the crystalline silicon cell 1. Optionally, the structure of the crystalline silicon cell 1 is, from bottom to top,: a first metal electrode layer 11, a first transparent electrode layer 12, a P-type base doping layer 13, a base bottom passivation layer 14, a substrate 15, a base surface passivation layer 16, an N-type base doping layer 17, and a tunneling layer 18. The structure of the perovskite cell 2 is, from bottom to top,: a hole transport layer 21, a perovskite absorption layer 22, a top passivation layer 23, an electron transport layer 24, and a top electrode layer 26. The top electrode layer 26 may include a second transparent electrode layer 261 and a second metal electrode layer 262 disposed on the surface of the second transparent electrode layer 261, wherein the second metal electrode layer 262 is disposed on the surface of the second transparent electrode layer 261.

[0053] In some embodiments, referring to FIG. 1 , the perovskite cell 2 may further include a buffer layer 25 disposed between the electron transport layer 24 and the top electrode layer 26 . Specifically, the buffer layer 25 is disposed between the electron transport layer 24 and the second transparent electrode layer 261 .

[0054] In some embodiments, referring to FIG. 1 , the perovskite cell 2 may further include an anti-reflection layer 27 disposed on a surface of the top electrode layer 26 . Specifically, the anti-reflection layer 27 is disposed on a surface of the second metal electrode layer 262 .

[0055] Referring to Figure 1, the specific structure of the crystalline silicon / perovskite tandem solar cell provided in the embodiment of the present application is as follows from top to bottom: a first metal electrode layer 11, a first transparent electrode layer 12, a P-type base doping layer 13, a base bottom passivation layer 14, a substrate 15, a base surface passivation layer 16, an N-type base doping layer 17, a tunneling layer 18, a hole transport layer 21, a perovskite absorption layer 22, a top passivation layer 23, an electron transport layer 24, a buffer layer 25, a second transparent electrode layer 261, a second metal electrode layer 262, and an anti-reflection layer 27. The steps for preparing the crystalline silicon / perovskite tandem solar cell are as follows:

[0056] Step 1: a base bottom passivation layer 14 and a P-type base doping layer 13 are sequentially formed on the bottom surface of the substrate 15 , and a base surface passivation layer 16 and an N-type base doping layer 17 are sequentially formed on the surface of the substrate 15 .

[0057] Step 2: Prepare the first transparent electrode layer 12. Optionally, magnetron sputtering is used. Place the sample in a magnetron sputtering device, set up an ITO (Indium Tin Oxide) target, and control the power between 50-200W. Specifically, in this embodiment, the controlled power is 60W, the operation time is 1.5 hours, and the film thickness is 100nm.

[0058] Step 3: Prepare the first metal electrode layer 11. Optionally, the prepared substrate sample is placed on a mask plate and placed in a chamber of an evaporation machine using an evaporation method. The evaporation vacuum is 5×10 -5 -2×10 -4 Pa, the evaporation temperature is 500-2000 ° C, and the evaporation rate is 0.1-5 Å / S. Specifically, in the embodiment of the present application, the evaporation vacuum is 2×10 -4 Pa, the evaporation voltage was adjusted to the evaporation temperature, the evaporation rate was controlled at 2.5Å / S, and silver was evaporated onto the film with a thickness of 200nm.

[0059] Step 4: Form a tunneling layer 18 on the surface of the N-type base doped layer 17. Optionally, tunneling layer 18 can be formed using atomic layer deposition, magnetron sputtering, or wet chemical methods. Specifically, in this embodiment of the present application, magnetron sputtering can be used. After placing the sample on a mask, it is placed in a magnetron sputtering device with a controlled power of 60 W, a run time of 1 hour, and a film thickness of 40 nm.

[0060] Step 5: Prepare a hole transport layer 21. The hole transport layer 21 can be at least one of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly-3-hexylthiophene (P3HT), nickel oxide (NiOx), molybdenum trioxide (MoO3), cuprous iodide (CuI), and cuprous thiocyanate (CuSCN).

[0061] Alternatively, the hole transport layer 21 dispersion can be evenly coated on the surface of the tunneling layer 18 by spin coating at a speed of 1000-5000 rpm for 10-100 seconds. After the spin coating is completed, an annealing operation is performed at a temperature of 300-600° C. for 10-50 minutes.

[0062] Optionally, a magnetron sputtering method may be used, and the prepared substrate is placed in a magnetron sputtering device with a controlled power of 30-90W.

[0063] In this embodiment, a spin coating method can be used. The substrate is treated in a UV-Ozone cleaner for 15 minutes. A hole transport layer 21 dispersion is prepared by dissolving 0.05 mol of NiOx powder in 1 ml of ultrapure water and ultrasonically vibrating for 20 minutes. The hole transport layer 21 dispersion is evenly coated on the surface of the substrate. The spin coating speed is set to 2000 rpm, the spin coating time is 40 seconds, and the solution volume is 100 μl. After spin coating, an annealing operation is performed at 450°C for 30 minutes, with a thickness of approximately 20 nm.

[0064] Step 6: Prepare the perovskite absorption layer 22.

[0065] Optionally, a spin coating method can be used to prepare a perovskite precursor solution, and the perovskite precursor solution is evenly coated on the surface of the hole transport layer 21, and then an anti-solvent is used for dynamic spin coating, the spin coating speed is 1200-6000 rpm, the spin coating time is 20-120s, and the anti-solvent titration time is 10-50s after the start of the spin coating. After the spin coating is completed, an annealing operation is performed, the annealing temperature is 50-150°C, and the annealing time is 5-40min. The dissolving solvent of the perovskite precursor solution includes at least one of dimethylformamide (DMF), G-butyrolactone (GBL), dimethyl sulfoxide (DMSO) and N,N-dimethylacetamide (DMA), and the solvent ratio is between 0-3:10-7. The anti-solvent may include at least one of toluene (Tol), chlorobenzene (CB), and ethyl acetate (EA).

[0066] Alternatively, a flash evaporation method can be used to prepare a perovskite precursor solution, which is then evenly coated on the surface of the hole transport layer 21 at a spin coating speed of 1000-6000 rpm for 20-120 seconds. After spin coating, a flash evaporation operation is performed for 10-60 seconds at a flash evaporation temperature of 0-100°C. After flash evaporation, an annealing treatment is performed at a temperature of 50-150°C for 5-40 minutes.

[0067] Optionally, a vapor deposition method can be used to prepare a perovskite precursor powder, and the perovskite precursor powder is evaporated onto the surface of the hole transport layer 21. The vacuum degree of the vapor deposition is 1-3×10 -4 Pa, and the evaporation temperature is 200-700 ° C. Among them, the perovskite precursor can be ABX3 structure perovskite, which is adjusted by stoichiometric ratio and dissolved in organic solvent, with a concentration between 1.5-2M. Among them, in the ABX3 structure perovskite, the A position is an organic cation, including CH3NH3 + (MA + ), NH2CH=NH2 + (FA + ), CH3CH2NH3 + or Cs + At least one of; B position is a metal cation, including Pb 2+ 、Sn 2+ At least one of; X is a halogen anion, including F - 、Cl - Br - , I - At least one of .

[0068] In the embodiment of the present application, the perovskite absorption layer 22 can be prepared by a flash evaporation method. Specifically, a perovskite precursor solution is prepared, 1M perovskite powder is weighed and dissolved in 1ml of DMF (N,N-Dimethylformamide) and DMSO (Dimethyl sulfoxide) solvent, and 1mol% Meo-4PACz ([4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid) powder is doped at a solvent ratio of 8:2. The sample is magnetically stirred for 30 minutes, and then the sample is placed on the base of a spin coater. The spin coating speed is set to 3500rpm and the spin coating time is set to 30s. The amount of perovskite precursor solution is 120ul and coated on the surface of the sample. After spin coating, the sample was placed on a flash evaporation table, and the flash evaporation time was set to 30s and the flash evaporation temperature was set to 30°C. After the flash evaporation, annealing was performed, and the annealing temperature was set to 100°C and the annealing time was set to 15min. The thickness was about 500nm.

[0069] Step 7: Prepare the top passivation layer 23 by light injection process. Specifically, the stable thin film substrate is excited to form a metastable thin film substrate by light irradiation; under continuous light irradiation, the top passivation layer 23 is formed on the surface of the metastable thin film substrate.

[0070] Please refer to Figures 2 to 4. During the preparation of the top passivation layer 23, 1-sun simulated sunlight (i.e., the above-mentioned illumination) is introduced, with a light intensity of AM1.5G 1000mW / cm 2 , the stable film substrate is metastablely excited to form a metastable film substrate. On the metastable film substrate, the top passivation layer 23 can be prepared by spin coating. Optionally, a passivation layer dispersion is prepared and evenly coated on the surface of the perovskite absorption layer 22, and propylene diamine iodine is dissolved in an organic solvent, which includes but is not limited to methanol, ethanol or isopropanol, and ultrasonically dissolved and spin-coated. The concentration of propylene diamine iodine is 0.1-6 mg / ml, the ultrasonic time is 0-30 min, the spin coating speed is 1000-7000 rpm, and the spin coating time is 20-120 s. After the spin coating is completed, an annealing operation is performed, the annealing temperature is 40-160 ° C, and the annealing time is 5-40 min. The embodiment of the present application can use a spin coating method to prepare the top passivation layer 23, wherein the concentration of propylene diamine iodine is 0.5 mg / ml, the spin coating speed is 6000 rpm, and the spin coating time is 60 s. The annealing temperature is 100 ° C and the annealing time is 10 min. The entire preparation process of the top passivation layer 23 is carried out under simulated sunlight, and the total duration is about 15 minutes.

[0071] Optionally, the top passivation layer 23 can also be sprayed. Specifically, the passivation layer dispersion is sprayed on the surface of the perovskite absorption layer 22 at a spraying rate of 0-100 cm / s. After spraying, an annealing operation is performed at an annealing temperature of 20-170° C. for 0-30 minutes.

[0072] Alternatively, the top passivation layer 23 may include at least one of propylenediamine bromide, butylammonium chloride, butylammonium bromide, butylammonium iodide, N,N-dimethyl-1,3-propylenediamine hydrochloride, and dodecanediamine bromide.

[0073] Optionally, the top passivation layer 23 may also include at least one of magnesium fluoride, lithium fluoride, and sodium fluoride.

[0074] Step 8: Prepare the electron transport layer 24. The electron transport layer 24 is zinc oxide (ZnO), tin dioxide (SnO2), titanium dioxide (TiO2), [6,6]-phenyl C61 butyric acid methyl ester (PC 61 BM), carbon 60 (C 60 ), at least one of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP).

[0075] Optionally, the electron transport layer 24 dispersion can be evenly coated on the surface of the top passivation layer 23 by spin coating, with a spin coating speed of 500-4000 rpm and a spin coating time of 10-80 s.

[0076] Optionally, the electron transport layer 24 material can be evaporated onto the surface of the top passivation layer 23 by evaporation method, and the evaporation vacuum degree is 5×10 -5 -5×10 -4 Pa, the evaporation temperature is 100-400℃, and the evaporation rate is 0.05-1Å / S.

[0077] The embodiment of the present application can adopt the evaporation method to prepare the electron transport layer 24. Specifically, the substrate sample is placed on the mask and placed in the evaporation chamber. The vacuum degree of the evaporation is 1×10 -4 Pa, the evaporation voltage was adjusted to the evaporation temperature, and the evaporation rate was controlled at 0.1-0.15Å / S. 60 Evaporated onto the film with a thickness of 20nm.

[0078] Step 9: Prepare a buffer layer 25. The buffer layer 25 is made of at least one of zinc oxide (ZnO), tin dioxide (SnO2), and titanium dioxide (TiO2). The thickness of the buffer layer 25 can range from 0 to 30 nm.

[0079] Optionally, the electron transport layer 24 material can be deposited onto the surface of the electron transport layer 24 using an atomic layer deposition device, with a deposition vacuum of 0-1×10 4 Pa, the deposition pipe temperature is between 50-150°C, and the deposition chamber temperature is 40-150°C.

[0080] Optionally, the modification layer material of the electron transport layer 24 can be evaporated onto the surface of the electron transport layer 24 by evaporation method, and the evaporation vacuum degree is 6×10 -5 -4×10 -4 Pa, the evaporation temperature is 100-500℃, and the evaporation rate is 0.05-1Å / S.

[0081] The embodiment of the present application can adopt the atomic layer deposition method, and the vacuum degree of the atomic layer deposition equipment is set to 0.5×10 4 Pa, the deposition channel temperature is between 60 ° C, the deposition chamber temperature is 70 ° C, and SnO2 is evaporated onto the layer film with a thickness of 15 nm.

[0082] Step 10: Prepare the second transparent electrode layer 261 .

[0083] Optionally, the transparent electrode material may be sputtered onto the surface of the modified layer of the electron transport layer 24 by magnetron sputtering, with the power controlled to be 30-200W.

[0084] Optionally, the transparent electrode material can be evaporated onto the surface of the modified layer of the electron transport layer 24 by evaporation method, and the evaporation vacuum degree is 1×10 -5 -5×10 -4 Pa, the evaporation temperature is 1000-2000℃, and the evaporation rate is 0.05-3Å / S.

[0085] The embodiment of the present application can adopt a magnetron sputtering method, which is similar to the preparation method of preparing the first transparent electrode layer 12 in step 2, setting an IZO (Indium Zinc Oxide) target material, controlling the power to 50W, the operation time to 1h, and the layer thickness to 10nm.

[0086] Step 11: Prepare the second metal electrode layer 262. Specifically, the process is similar to preparing the first metal electrode layer 11, except that the mask is different and the thickness is 100 nm.

[0087] Step 12: Prepare the anti-reflection layer 27. Alternatively, the anti-reflection layer 27 can be prepared by magnetron sputtering or evaporation. Specifically, the method for preparing the anti-reflection layer 27 in this embodiment of the application is similar to the method for preparing the top passivation layer 23. The evaporation rate is controlled at 2 Å / s, and magnesium fluoride is evaporated onto the film to a thickness of 100 nm. The anti-reflection layer 27 can be at least one of magnesium fluoride, lithium fluoride (LiF), sodium fluoride (NaF), and silicon oxide (SiO2).

[0088] Optionally, the first transparent electrode layer 12 and the second transparent electrode layer 261 may be at least one of indium tin oxide (ITO), indium zinc oxide (IZO), and aluminum zinc oxide (AZO).

[0089] Optionally, the second metal electrode layer 262 may be at least one of silver (Ag), gold (Au), copper (Cu), aluminum (Al), and carbon (C).

[0090] Optionally, the thickness of the hole transport layer 21 , the perovskite absorption layer 22 , the electron transport layer 24 , the second transparent electrode layer 261 , the second metal electrode layer 262 and the anti-reflection layer 27 may be in the range of 1-600 nm.

[0091] In order to verify the performance of the crystalline silicon / perovskite tandem solar cell provided in the embodiment of the present application, the present application provides six comparative examples for demonstration. Comparative Example 1 provides a method based on a light intensity of 600mW / cm 2 Prepare a crystalline silicon / perovskite tandem solar cell with a top passivation layer 23. Comparative Example 2 provides a method based on a light intensity of 800 mW / cm 2 Prepare a crystalline silicon / perovskite tandem solar cell with a top passivation layer 23. Comparative Example 3 provides a method based on a light intensity of 1200 mW / cm 2 Prepare a crystalline silicon / perovskite tandem solar cell with a top passivation layer 23. Comparative Example 4 provides a method based on a light intensity of 1400 mW / cm 2Preparation of a crystalline silicon / perovskite tandem solar cell with a top passivation layer 23. Comparative Example 5 provides a crystalline silicon / perovskite tandem solar cell in which simulated sunlight injection is performed before the preparation of the top passivation layer 23 and the top passivation layer 23 is prepared, and the illumination time is 15 minutes. Comparative Example 6 provides a crystalline silicon / perovskite tandem solar cell in which the top passivation layer 23 is prepared based on a conventional process. This comparative example 6 is basically the same as the preparation method of the embodiment of the present application, except that the light injection process is not used in step 7. That is, a spin coating method is used to prepare a dispersion of the top passivation layer 23 and evenly coat it on the surface of the perovskite absorption layer 22. Propylene diamine iodine is dissolved in an organic solvent including but not limited to methanol, ethanol or isopropanol, ultrasonically dissolved and spin-coated. The concentration of propylene diamine iodine is 0.5 mg / ml, the ultrasonic time is 30 minutes, the spin coating speed is 6000 rpm, and the spin coating time is 60 seconds. After the spin coating is completed, an annealing operation is performed, the annealing temperature is 100°C, and the annealing time is 10 minutes.

[0092] The embodiment of the present application was compared with comparative examples 1 to 6. A standard solar light intensity calibration was performed using a solar simulator. 2 The device of the embodiment was subjected to long-term IV test, with the starting voltage set to 1.95V, the cut-off voltage set to 0V, and the range set to 100mA. The test results are shown in the following table. Device open circuit voltage (V) short circuit current (mA / cm 2 ) Photoelectric conversion efficiency (%) Efficiency decay rate (% / year) Example of the present application 1.98 19.5 3 2.20.2 Comparative example 1 1.92 19.5 2 9.8 2.1 Comparative example 2 1.92 19.4 3 0.12.2 Comparative example 3 1.96 19.4 3 0.21.8 Comparative example 4 1.94 19.3 29.22.1 Comparative example 5 1.90 19.4 29.22.2 Comparative example 6 1.88 19.4 2 8.24.5

[0093] From the comparison of the above tables we can see that:

[0094] 1. This method for preparing a passivation layer not only passivates existing defects in the stable film substrate but also passivates sites where perovskite defects may form under illumination. This overcomes the new defects that may form in metastable perovskite films under illumination, further improving the passivation effect. The embodiment of the present application that incorporates a light injection process exhibits higher open-circuit voltage and photoelectric conversion efficiency compared to Comparative Example 3 due to its lower defect density and non-recombination losses.

[0095] 2. This passivation layer preparation method can also effectively suppress the photoinduced phase separation phenomenon of wide-bandgap perovskites, improving the photoelectric conversion efficiency and stability of crystalline silicon / perovskite tandem solar cells. Compared with comparative example 3, the embodiment of the present application that introduces the light injection process has a lower efficiency decay rate.

[0096] 3. The method for preparing the passivation layer is also intended to optimize the intensity and method of the light injection process. The light intensity required by the optimized light injection process is 1000mW / cm 2 , and the light injection process needs to be performed simultaneously with the preparation of the top passivation layer 23. Comparative Examples 1 to 4 used light injection of varying light intensities, while Comparative Example 5 chose to introduce the light injection process before the preparation of the top passivation layer 23. The light injection passivation effects of Comparative Examples 1 to 5 were not as superior as those of the present embodiment. In comparison, the present embodiment achieved higher open-circuit voltage and photoelectric conversion efficiency, as well as lower efficiency decay.

[0097] 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 passivation layer, characterized in that: It comprises a crystalline silicon cell and a perovskite cell disposed on the crystalline silicon cell, wherein the perovskite cell comprises a hole transport layer disposed on the surface of the crystalline silicon cell, a perovskite absorption layer disposed on the surface of the hole transport layer, a top passivation layer disposed on the surface of the perovskite absorption layer, an electron transport layer disposed on the surface of the top passivation layer, and a top electrode layer disposed on the surface of the electron transport layer; the crystalline silicon cell, the hole transport layer and the perovskite absorption layer are combined to form a stable thin film substrate; The stable thin film substrate is excited by light to form a metastable thin film substrate; and the top passivation layer is formed on the surface of the metastable thin film substrate under continuous light irradiation.

2. The method for preparing a passivation layer according to claim 1, wherein Includes steps: Prepare a passivation layer dispersion, and evenly apply the passivation layer dispersion on the surface of the perovskite absorption layer; Dissolving propylenediamine iodide in an organic solvent and performing ultrasonic dissolution, and spin-coating the dissolved solution on the surface of the perovskite absorption layer; After the spin coating is completed, an annealing process is performed to form the top passivation layer.

3. The method for preparing a passivation layer according to claim 1, wherein Includes steps: Preparing a passivation layer dispersion, and spraying the passivation layer dispersion on the surface of the perovskite absorption layer; After the spraying is completed, an annealing process is performed to form the top passivation layer.

4. The method for preparing a passivation layer according to any one of claims 1 to 3, characterized in that: The top passivation layer includes at least one of propylenediamine bromide, butylammonium chloride, butylammonium bromide, butylammonium iodide, N,N-dimethyl-1,3-propylenediamine hydrochloride, and dodecanediamine bromide.

5. The method for preparing a passivation layer according to any one of claims 1 to 3, characterized in that: The top passivation layer includes at least one of magnesium fluoride, lithium fluoride, and sodium fluoride.

6. The method for preparing a passivation layer according to any one of claims 1 to 3, characterized in that: Includes steps: Preparing a perovskite precursor solution, and uniformly coating the perovskite precursor solution on the surface of the hole transport layer; Dynamic spin coating using antisolvent; After the spin coating is completed, an annealing treatment is performed to form the perovskite absorption layer; or, after the spin coating is completed, a flash evaporation treatment is performed, and after the flash evaporation is completed, an annealing treatment is performed to form the perovskite absorption layer.

7. The method for preparing a passivation layer according to claim 6, wherein: The perovskite precursor solution is prepared by dissolving perovskite with ABX3 structure in an organic solvent, and the concentration range of the perovskite precursor solution is 1.5-2M.

8. The method for preparing a passivation layer according to claim 7, wherein: At In the ABX3 structured perovskite, the A position is an organic cation, including CH3NH3 + (MA+), NH2CH=NH2 + (FA+), CH3CH2NH3 + or Cs + At least one of; B position is a metal cation, including Pb 2+ Sn 2+ At least one of; X is a halogen anion, including F - , Cl - Br - ,I - At least one of .

9. The method for preparing a passivation layer according to any one of claims 1 to 3, characterized in that: The method comprises the steps of: preparing perovskite precursor powder, and evaporating the perovskite precursor powder onto the surface of the hole transport layer.

10. The method for preparing a passivation layer according to any one of claims 1 to 3, characterized in that: The crystalline silicon cell includes a first metal electrode layer, a first transparent electrode layer arranged on the first metal electrode layer, a P-type base doping layer arranged on the first transparent electrode layer, a base bottom surface passivation layer arranged on the P-type base doping layer, a substrate arranged on the base bottom surface passivation layer, a base surface passivation layer arranged on the substrate, an N-type base doping layer arranged on the base surface passivation layer, and a tunneling layer arranged on the N-type base doping layer.

11. The method for preparing a passivation layer according to claims 1-3, characterized in that: The top electrode layer includes a second transparent electrode layer and a second metal electrode layer disposed on a surface of the second transparent electrode layer.

12. The method for preparing a passivation layer according to claims 1-3, characterized in that: The perovskite cell further includes a buffer layer disposed between the electron transport layer and the top electrode layer.

13. The method for preparing a passivation layer according to claim 12, wherein: The buffer layer is at least one of zinc oxide (ZnO), tin dioxide (SnO2), and titanium dioxide (TiO2).

14. The method for preparing a passivation layer according to claims 1-3, characterized in that: The perovskite cell further includes an anti-reflection layer disposed on a surface of the top electrode layer.

15. The method for preparing a passivation layer according to claim 14, characterized in that: The anti-reflection layer is at least one of magnesium fluoride, lithium fluoride (LiF), sodium fluoride (NaF), and silicon oxide (SiO2).

16. The method for preparing a passivation layer according to claims 1-3, characterized in that: The hole transport layer is at least one of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly-3-hexylthiophene (P3HT), nickel oxide (NiOx), molybdenum trioxide (MoO3), cuprous iodide (CuI), and cuprous thiocyanate (CuSCN).

17. The method for preparing a passivation layer according to claims 1-3, characterized in that: The electron transport layer is zinc oxide (ZnO), tin dioxide (SnO2), titanium dioxide (TiO2), [6,6]-phenyl C61 butyric acid methyl ester (PC 61 BM), carbon 60 (C 60 ), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP).

18. A crystalline silicon / perovskite tandem solar cell, characterized in that: The method for preparing a passivation layer is adopted as claimed in any one of claims 1 to 17.

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