Use of 1,4-disubstituted fullerenes in solar cells

Abstract

The application provides application of 1,4-disubstituted fullerene in a solar cell. The 1,4-disubstituted fullerene is 1-chlorophenyl-4-(4-chlorophenyl)[60]fullerene, which has a structure shown in formula (I). When the 1,4-disubstituted fullerene is introduced into the solar cell as an additive, on one hand, the electron extraction efficiency can be improved, and the transmission of electrons and holes is more balanced; on the other hand, the defects existing in the perovskite active layer itself can be effectively passivated, the crystallization of the perovskite active material can be regulated, and the phase separation can be inhibited, so that the photoelectric conversion efficiency and stability of the solar cell are improved. In the chemical structure of the 1,4-disubstituted fullerene, two substituents of C 60 each contain one chlorine atom, multi-site chlorine passivation can be achieved, and the interface defects are reduced; compared with passivation by using an organic chloride salt, the introduction of the above-mentioned fullerene derivative can inhibit the change of the structure of the perovskite active material, so that the photoelectric conversion efficiency and stability of the solar cell are improved.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and more specifically, to the application of a 1,4-disubstituted fullerene in solar cells. Background Technology

[0002] Because electrons diffuse for a shorter length than holes, holes are more easily extracted than electrons in perovskites. This imbalance in electron and hole diffusion lengths is a common characteristic of metal halide perovskites. Therefore, improving charge extraction efficiency is crucial for further enhancing device performance.

[0003] Fullerenes and their derivatives, due to their high electron transport performance and good energy level matching with perovskite materials, have been applied in perovskite solar cells. Introducing fullerenes and their derivatives as additives into the perovskite layer can improve electron extraction efficiency, resulting in a more balanced electron and hole transport. Furthermore, it can effectively passivate defects in the perovskite film itself and suppress ion migration, thereby improving the overall performance of the device.

[0004] Using organic halide salts (especially chlorides) to passivate defects is an effective way to improve the power conversion efficiency of perovskite solar cells because the Pb-Cl bond is stronger than the Pb-I and Pb-Br bonds. However, the small radius Cl... - Anions can easily be incorporated into the perovskite lattice, thereby distorting the lead halide octahedron and reducing photovoltaic performance.

[0005] When perovskite solar cells are used as the top cells in tandem solar cells, wide-bandgap perovskite materials are required. To improve the efficiency of tandem solar cells, there is an urgent need for high-performance and stable wide-bandgap perovskite solar cells. However, the widening of the perovskite bandgap leads to difficulties in improving the efficiency of perovskite solar cells and the phase separation phenomenon in perovskite.

[0006] Therefore, researching and developing a novel fullerene derivative is of great significance for improving the efficiency and stability of perovskite solar cells and tandem solar cells. Summary of the Invention

[0007] The main objective of this invention is to provide an application of 1,4-disubstituted fullerene in solar cells, in order to solve the problems of low overall efficiency and poor stability of perovskite solar cells and tandem solar cells caused by defect states of the perovskite itself or the transport layer.

[0008] To achieve the above objectives, the present invention provides an application of a 1,4-disubstituted fullerene in a solar cell, wherein the 1,4-disubstituted fullerene is a 1-chlorophenyl-4-(4-chlorophenyl)

[60] fullerene having the structure shown in formula (I):

[0009]

[0010] To achieve the above objectives, another aspect of the present invention provides a perovskite solar cell comprising a functional layer containing a fullerene derivative, wherein the fullerene derivative is a 1,4-disubstituted fullerene, and the 1,4-disubstituted fullerene is a 1-chlorophenyl-4-(4-chlorophenyl)

[60] fullerene having the structure shown in formula (I):

[0011]

[0012] Furthermore, the perovskite solar cell is a pin-type perovskite solar cell.

[0013] Furthermore, the perovskite solar cell includes a first transparent conductive substrate, a first hole transport layer, a functional layer, a first electron transport layer, and a first cathode buffer layer stacked sequentially. The perovskite solar cell also includes a first metal electrode layer, which includes a plurality of first metal electrodes, wherein a portion of the first metal electrodes are disposed on the surface of the first cathode buffer layer away from the first electron transport layer, and a portion of the first metal electrodes are disposed on the conductive surface of the first transparent conductive substrate. The functional layer is a first perovskite active layer doped with 1,4-disubstituted fullerene. Preferably, the doping amount of 1,4-disubstituted fullerene is 0.01 to 0.5 wt% based on the weight percentage of the first perovskite active layer; more preferably, it is 0.04 to 0.06 wt%.

[0014] Further, the first transparent conductive substrate is selected from ITO conductive glass, FTO conductive glass, or AZO conductive glass; preferably, the material of the first hole transport layer is selected from one or more of nickel oxide, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], and [2-(9H-carbazole-9-yl)ethyl]phosphoric acid; preferably, the material of the first perovskite active layer is selected from ABX3, wherein A is CH3NH3. + NH=CHNH3 + Cs + 、or Rb + B is Pb 2+ Sn 2+ Or Ge 2+ X is Cl, Br, I, or SCN. - or COO - The preferred material for the first electron transport layer is selected from SnO2, ZnO, and C.60 One or more of PCBM; preferably, the material of the first cathode buffer layer is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline; preferably, the material of the first metal electrode layer is selected from one or more of Au, Ag, Cu, and Al.

[0015] Further, the perovskite solar cell includes a second transparent conductive substrate, a second hole transport layer, a second perovskite active layer, a functional layer, a second electron transport layer, and a second cathode buffer layer stacked sequentially. The perovskite solar cell also includes a second metal electrode layer, which comprises multiple second metal electrodes, some of which are disposed on the surface of the second cathode buffer layer away from the second electron transport layer, and some of which are disposed on the conductive surface of the first transparent conductive substrate. The functional layer is a passivation layer composed of 1,4-disubstituted fullerene. The material of the second perovskite active layer is a second perovskite active material, or a mixture of 1,4-disubstituted fullerene and the second perovskite active material. Preferably, the thickness of the passivation layer is 10–20 nm. Preferably, when the material of the second perovskite active layer is a mixture of 1,4-disubstituted fullerene and the second perovskite active material, the doping amount of 1,4-disubstituted fullerene is 0.04–0.06 wt% by weight of the second perovskite active layer.

[0016] Further, the second transparent conductive substrate is selected from ITO conductive glass, FTO conductive glass, or AZO conductive glass; preferably, the material of the second hole transport layer is selected from one or more of nickel oxide, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], and [2-(9H-carbazole-9-yl)ethyl]phosphoric acid; preferably, the material of the second perovskite active layer is selected from ABX3, wherein A is CH3NH3. + NH=CHNH3 + Cs + 、or Rb + B is Pb 2+ Sn 2+ Or Ge 2+ X is Cl, Br, I, or SCN. - or COO - The preferred materials for the second electron transport layer are independently selected from SnO2, ZnO, and C. 60 The material of the second cathode buffer layer is preferably 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline; the material of the second metal electrode layer is preferably selected from one or more of Au, Ag, Cu, and Al.

[0017] Furthermore, the perovskite solar cell is a nip-type perovskite solar cell.

[0018] Further, the perovskite solar cell includes a third transparent conductive substrate, a third electron transport layer, a functional layer, a third perovskite active layer, and a third hole transport layer stacked sequentially. The perovskite solar cell also includes a third metal electrode layer, which comprises multiple third metal electrodes, some of which are disposed on the surface of the third hole transport layer away from the third perovskite active layer, and some of which are disposed on the conductive surface of the first transparent conductive substrate. The functional layer is an interface modification layer made of 1,4-disubstituted fullerene. The third perovskite active layer is made of a third perovskite active material, or a mixture of 1,4-disubstituted fullerene and the third perovskite active material. Preferably, the thickness of the interface modification layer is 1–5 nm. Preferably, the third transparent conductive substrate is selected from ITO conductive glass, FTO conductive glass, or AZO conductive glass. The material of the third electron transport layer is selected from one or more of SnO2, ZnO, and TiO2. Preferably, the material of the third perovskite active layer is selected from ABX3, where A is CH3NH3. + NH=CHNH3 + Cs + 、or Rb + B is Pb 2+ Sn 2+ Or Ge 2+ X is Cl, Br, I, or SCN. - or COO - Preferably, the material of the third hole transport layer is selected from one or more of nickel oxide, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], and 2,2',7,7'-tetratetra(N,N-di(4-methoxyphenyl)amino)-9,9'-spirodifluorene; preferably, the material of the third metal electrode layer is selected from one or more of Au, Ag, Cu, and Al; preferably, when the material of the third perovskite active layer is a mixture of 1,4-disubstituted fullerene and the third perovskite active material, the doping amount of 1,4-disubstituted fullerene is 0.04 to 0.06 wt% based on the weight percentage of the third perovskite active layer.

[0019] Another aspect of the present invention provides a tandem solar cell, which is a perovskite solar top cell and a crystalline silicon solar bottom cell stacked together. The perovskite solar top cell is the perovskite solar cell provided in this application, and the crystalline silicon solar bottom cell is HJT, TOPCon, PERC, IBC or HBC.

[0020] By applying the technical solution of this invention, 1,4-disubstituted fullerenes can be introduced into solar cells as a fullerene derivative additive. On the one hand, it can improve electron extraction efficiency and make the transport of electrons and holes more balanced. On the other hand, when the above-mentioned fullerene derivatives are applied to perovskite solar cells or tandem solar cells, they can effectively passivate the defects in the perovskite active layer itself, regulate the crystallization of the perovskite active material, and suppress phase separation, thereby improving the photoelectric conversion efficiency and stability of the solar cell.

[0021] In the chemical structure of the 1,4-disubstituted fullerene provided in this application, C 60 Each of the two substituents contains a chlorine atom, thus its application in solar cells can achieve multi-site chlorine passivation, reducing uncoordinated Pb. 2+ Ion defects and oxygen vacancies lead to interface defects; on the other hand, compared with passivation using organochloride salts, when the above-mentioned fullerene derivatives are applied to perovskite solar cells or tandem solar cells, they can suppress the doping of chlorine atoms into the lattice of perovskite active materials, so that the perovskite active materials can maintain their original octahedral structure, thereby improving the photoelectric conversion efficiency and stability of solar cells while exerting their passivation effect. Attached Figure Description

[0022] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0023] Figure 1 A schematic diagram of the structure of a perovskite solar cell according to a preferred embodiment of the present invention is shown;

[0024] Figure 2 A schematic diagram of the structure of a perovskite solar cell according to a preferred embodiment of the present invention is shown;

[0025] Figure 3 A schematic diagram of a perovskite solar cell according to a preferred embodiment of the present invention is shown.

[0026] The above figures include the following reference numerals:

[0027] 11. First transparent conductive substrate; 12. First hole transport layer; 13. First electron transport layer; 14. First cathode buffer layer; 15. First metal electrode; 16. First perovskite active layer;

[0028] 17. Second transparent conductive substrate; 18. Second hole transport layer; 19. Second perovskite active layer; 20. Second electron transport layer; 21. Second cathode buffer layer; 22. Second metal electrode; 23. Passivation layer;

[0029] 24. Third transparent conductive substrate; 25. Third electron transport layer; 26. Third perovskite active layer; 27. Third hole transport layer; 28. Third metal electrode; 29. ​​Interface modification layer. Detailed Implementation

[0030] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0031] As described in the background art, existing perovskite solar cells and tandem solar cells suffer from low overall cell efficiency and poor stability due to defect states in the perovskite itself or the transport layer. To solve the above technical problems, this application provides an application of a 1,4-disubstituted fullerene in a solar cell, wherein the 1,4-disubstituted fullerene is 1-chlorophenyl-4-(4-chlorophenyl)

[60] fullerene, which has the structure shown in formula (I):

[0032]

[0033] 1,4-Disubstituted fullerenes can be introduced into solar cells as a fullerene derivative additive. On the one hand, they can improve electron extraction efficiency and make the transport of electrons and holes more balanced. On the other hand, when the above-mentioned fullerene derivatives are applied to perovskite solar cells or tandem solar cells, they can effectively passivate the defects in the perovskite active layer itself, regulate the crystallization of perovskite active materials, and suppress phase separation, thereby improving the photoelectric conversion efficiency and stability of solar cells.

[0034] In the chemical structure of the 1,4-disubstituted fullerene provided in this application, C 60 Each of the two substituents contains a chlorine atom, thus its application in solar cells can achieve multi-site chlorine passivation, reducing uncoordinated Pb. 2+ Ion defects and oxygen vacancies lead to interface defects; on the other hand, compared with passivation using organochloride salts, when the above-mentioned 1,4-disubstituted fullerenes are applied to perovskite solar cells or tandem solar cells, chlorine atom doping into the lattice of the perovskite active material can be suppressed, so that the perovskite active material can maintain its original octahedral structure, thereby improving the photoelectric conversion efficiency and stability of the solar cell while exerting its passivation effect.

[0035] A second aspect of this application also provides a perovskite solar cell comprising a functional layer containing a fullerene derivative, wherein the fullerene derivative is a 1,4-disubstituted fullerene, and the 1,4-disubstituted fullerene is a 1-chlorophenyl-4-(4-chlorophenyl)

[60] fullerene having the structure shown in formula (I):

[0036]

[0037] The aforementioned 1,4-disubstituted fullerenes can be introduced into solar cells as a fullerene derivative additive. On the one hand, they can improve electron extraction efficiency and make the transport of electrons and holes more balanced. On the other hand, when the aforementioned 1,4-disubstituted fullerenes are applied to perovskite solar cells, they can effectively passivate the defects in the perovskite active layer itself and suppress phase separation, thereby improving the photoelectric conversion efficiency and stability of the solar cells.

[0038] In the above chemical structure of 1,4-disubstituted fullerenes, C 60 Each of the two substituents contains a chlorine atom, thus its application in solar cells can achieve multi-site chlorine passivation, reducing uncoordinated Pb. 2+ Ion defects and oxygen vacancies lead to interface defects; on the other hand, compared with passivation using organochloride salts, when the above-mentioned 1,4-disubstituted fullerenes are applied to perovskite solar cells, chlorine atom doping into the lattice of the perovskite active material can be suppressed, so that the perovskite active material can maintain its original octahedral structure, thereby improving the photoelectric conversion efficiency and stability of the solar cell while exerting its passivation effect.

[0039] In a preferred embodiment, the perovskite solar cell is a pin-type perovskite solar cell. The perovskite solar cell has an inverted (pin) structure.

[0040] In a preferred embodiment, such as Figure 1 As shown, the perovskite solar cell includes a first transparent conductive substrate 11, a first hole transport layer 12, a functional layer, a first electron transport layer 13, and a first cathode buffer layer 14, which are stacked sequentially. The perovskite solar cell also includes a first metal electrode layer, which includes a plurality of first metal electrodes 15, wherein a portion of the first metal electrodes 15 are disposed on the surface of the first cathode buffer layer 14 away from the first electron transport layer 13, and a portion of the first metal electrodes 15 are disposed on the conductive surface of the first transparent conductive substrate 11; the functional layer is a first perovskite active layer 16 doped with 1,4-disubstituted fullerene.

[0041] Traditional pin-type perovskite solar cells do not contain the functional layer described in this application. Compared to traditional pin-type perovskite solar cells, doping the first perovskite active layer 16 with the 1,4-disubstituted fullerene is beneficial for improving electron extraction efficiency, passivating defects in the first perovskite active layer 16 itself, and suppressing phase separation, thereby improving the photoelectric conversion efficiency and stability of the pin-type perovskite solar cell.

[0042] In a preferred embodiment, the layers on the surface of the ITO conductive glass (including the first transparent conductive substrate 11, the first hole transport layer 12, the functional layer, the first electron transport layer 13 and the first cathode buffer layer 14 stacked sequentially) are removed by etching or scraping, so that the area on the conductive plane of the ITO conductive glass where the first metal electrode is to be disposed is exposed, thereby forming the first metal electrode.

[0043] To further improve electron extraction efficiency and suppress phase separation, thereby further improving the photoelectric conversion efficiency and stability of pin-type perovskite solar cells, preferably, the doping amount of 1,4-disubstituted fullerene is 0.01 to 0.5 wt%, based on the weight percentage of the first perovskite active layer 16.

[0044] To further improve electron extraction efficiency and suppress phase separation, thereby further improving the photoelectric conversion efficiency and stability of pin-type perovskite solar cells, the doping amount of 1,4-disubstituted fullerene is preferably 0.04 to 0.06 wt% based on the weight percentage of the first perovskite active layer 16.

[0045] This application does not particularly limit the type of the first transparent conductive substrate 11, as long as it has high light transmittance, good conductivity, and is easy to coat or deposit, it can be conductive glass with a conductive film commonly used in the art. In a preferred embodiment, the first transparent conductive substrate 11 includes, but is not limited to, ITO conductive glass, FTO conductive glass, or AZO conductive glass.

[0046] The hole transport material should possess high hole mobility, energy levels matching the perovskite absorber layer, and good solution processability and molding properties. In a preferred embodiment, the material of the first hole transport layer 12 includes, but is not limited to, one or more of nickel oxide, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), and [2-(9H-carbazole-9-yl)ethyl]phosphoric acid (2-PACz). Among these, nickel oxide (NiO) is preferred. x It has a high hole mobility (approximately 0.141 cm). 2 V -1 s -1This material, with its wide band gap, is advantageous for suppressing charge recombination and improving hole extraction efficiency when used as the first hole transport layer 12. Compared to other types, the material used for the first hole transport layer 12 of the above type is beneficial for suppressing charge recombination and improving hole extraction efficiency, thereby improving the photoelectric conversion efficiency of perovskite solar cells.

[0047] In a preferred embodiment, the material of the first perovskite active layer 16 includes, but is not limited to, ABX3, wherein A is CH3NH3. + NH=CHNH3 + Cs + 、or Rb + B is Pb 2+ Sn 2+ Or Ge 2+ X is Cl, Br, I, or SCN. - or COO - The aforementioned materials have low exciton binding energy, making it easy to generate free electron-hole pairs when excited by external light. Moreover, these materials have narrow band gaps and wide absorption spectra, making them suitable as the material for the first perovskite active layer 16 to improve the absorption and utilization efficiency of solar energy, thereby enhancing the solar energy absorption and utilization efficiency of perovskite solar cells.

[0048] The electron transport material should be able to both effectively transport electrons and block holes. In a preferred embodiment, the material of the first electron transport layer 13 includes, but is not limited to, SnO2, ZnO, and C. 60 One or more of PCBMs are used. Compared to other types, using the above materials is beneficial to improving electron transport efficiency, which in turn is beneficial to improving the photocurrent and photoelectric conversion efficiency of perovskite solar cells.

[0049] In a preferred embodiment, the material of the first cathode buffer layer 14 is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP). Using the above-mentioned material for the first cathode buffer layer 14 helps to reduce the contact barrier between the first electron transport layer 13 and the first metal electrode layer 15, which helps to improve the transport efficiency at the interface, thereby helping to improve the photoelectric conversion efficiency of the perovskite solar cell.

[0050] The material of the first metal electrode layer 15 can be a metal material commonly used in the art. In a preferred embodiment, the material of the first metal electrode layer 15 includes, but is not limited to, one or more of Au, Ag, Cu, and Al.

[0051] In a preferred embodiment, such as Figure 2As shown, the perovskite solar cell includes a second transparent conductive substrate 17, a second hole transport layer 18, a second perovskite active layer 19, a functional layer, a second electron transport layer 20, and a second cathode buffer layer 21, which are stacked sequentially. The perovskite solar cell also includes a second metal electrode layer, which includes a plurality of second metal electrodes 22. Some of the second metal electrodes 22 are disposed on the surface of the second cathode buffer layer 21 away from the second electron transport layer 20, and some of the second metal electrodes 22 are disposed on the conductive surface of the first transparent conductive substrate 11. The functional layer is a passivation layer 23 composed of 1,4-disubstituted fullerene. The material of the second perovskite active layer 19 is a second perovskite active material or a mixture of 1,4-disubstituted fullerene and the second perovskite active material.

[0052] Traditional pin-type perovskite solar cells do not contain the functional layer described in this application. Compared to traditional pin-type perovskite solar cells, placing the passivation layer 23 composed of the aforementioned 1,4-disubstituted fullerene between the second perovskite active layer 19 and the second electron transport layer 20 is beneficial for improving electron extraction efficiency, reducing non-radiative recombination losses, passivating defects inherent in the second perovskite active layer 19 itself, and suppressing phase separation, thereby improving the photoelectric conversion efficiency and stability of the pin-type perovskite solar cell.

[0053] In a preferred embodiment, the layers on the surface of the ITO conductive glass (including the second transparent conductive substrate 17, the second hole transport layer 18, the second perovskite active layer 19, the functional layer, the second electron transport layer 20, and the second cathode buffer layer 21 stacked sequentially) are removed by etching or scraping, so that the area on the conductive plane of the ITO conductive glass where the second metal electrode is to be disposed is exposed, thereby forming the second metal electrode.

[0054] To further reduce non-radiative recombination losses and thus further improve the photoelectric conversion efficiency and stability of pin-type perovskite solar cells, preferably, when the material of the second perovskite active layer 19 is a mixture of 1,4-disubstituted fullerene and the second perovskite active material, the doping amount of 1,4-disubstituted fullerene is 0.04 to 0.06 wt% based on the weight percentage of the second perovskite active layer 19.

[0055] To further reduce non-radiative recombination losses and thus further improve the photoelectric conversion efficiency and stability of pin-type perovskite solar cells, the passivation layer 23 is preferably 10–20 nm thick.

[0056] This application does not specifically limit the second transparent conductive substrate 17, as long as it has high light transmittance, good conductivity, and is easy to coat or deposit, it can be conductive glass with a conductive film commonly used in the art. In a preferred embodiment, the second transparent conductive substrate 17 includes, but is not limited to, ITO conductive glass, FTO conductive glass, or AZO conductive glass.

[0057] The hole transport material should possess high hole mobility, energy levels matching the perovskite absorber layer, and good solution processability and molding properties. In a preferred embodiment, the material of the second hole transport layer 18 includes, but is not limited to, one or more of nickel oxide, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), and [2-(9H-carbazole-9-yl)ethyl]phosphoric acid (2-PACz). Among these, nickel oxide (NiO) is preferred. x It has a high hole mobility (approximately 0.141 cm). 2 V -1 s -1 This material, with its wide band gap, is advantageous for suppressing charge recombination and improving hole extraction efficiency when used as the second hole transport layer 18. Compared to other types, the material used for the second hole transport layer 18 described above is beneficial for suppressing charge recombination and improving hole extraction efficiency, thereby improving the photoelectric conversion efficiency of perovskite solar cells.

[0058] In a preferred embodiment, the material of the second perovskite active layer 19 includes, but is not limited to, ABX3, wherein A is CH3NH3. + NH=CHNH3 + Cs + 、or Rb + B is Pb 2+ Sn 2+ Or Ge 2+ X is Cl, Br, I, or SCN. - or COO - The material of the second perovskite active layer 19 has a small exciton binding energy, and it can easily generate free electron-hole pairs when excited by external light. Moreover, the material has a narrow band gap and a wide absorption spectrum, which is beneficial to improving the absorption and utilization efficiency of solar energy, thereby improving the absorption and utilization efficiency of solar energy in perovskite solar cells.

[0059] Electron transport materials should be able to both effectively transport electrons and block holes. In a preferred embodiment, the material of the second electron transport layer 20 is, independently including but not limited to, SnO2, ZnO, and C. 60One or more of PCBMs. Compared to other types, using the material of the second electron transport layer 20 described above is beneficial to improving electron transport efficiency, thereby improving the photocurrent and photoelectric conversion efficiency of perovskite solar cells.

[0060] In a preferred embodiment, the material of the second cathode buffer layer 21 is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline. Using the above-mentioned material for the second cathode buffer layer 21 helps to reduce the contact barrier between the second electron transport layer 20 and the second metal electrode layer 22, which helps to improve the transport efficiency at the interface, thereby improving the photoelectric conversion efficiency of the perovskite solar cell.

[0061] The material of the second metal electrode layer 22 can be a metal material commonly used in the art. In a preferred embodiment, the material of the second metal electrode layer 22 includes, but is not limited to, one or more of Au, Ag, Cu, and Al.

[0062] In a preferred embodiment, the perovskite solar cell is a nip-type perovskite solar cell. The perovskite solar cell has a positive (nip) structure.

[0063] In a preferred embodiment, such as Figure 3 As shown, the perovskite solar cell includes a third transparent conductive substrate 24, a third electron transport layer 25, a functional layer, a third perovskite active layer 26, and a third hole transport layer 27, which are stacked sequentially. The perovskite solar cell also includes a third metal electrode layer, which includes a plurality of third metal electrodes 28. Some of the third metal electrodes 28 are disposed on the surface of the third hole transport layer 27 away from the third perovskite active layer 26, and some of the third metal electrodes 28 are disposed on the conductive surface of the first transparent conductive substrate 11. The functional layer is an interface modification layer 29, which is made of 1,4-disubstituted fullerene. The material of the third perovskite active layer 26 is a third perovskite active material or a mixture of 1,4-disubstituted fullerene and the third perovskite active material.

[0064] The working principle of this perovskite solar cell is as follows: Under sunlight, the third perovskite active layer 26 absorbs photons to generate electron-hole pairs, which then break free to form free charge carriers. Electrons pass through the third electron transport layer 25 and are finally collected by the third transparent conductive substrate 24; holes pass through the third hole transport layer 27 and are finally collected by the third metal electrode layer 28; connecting the third transparent conductive substrate 24 and the third metal electrode layer 28 to form a closed circuit will generate a photocurrent.

[0065] In a preferred embodiment, the layers on the surface of the ITO conductive glass (including the third transparent conductive substrate 24, the third electron transport layer 25, the functional layer, the third perovskite active layer 26, and the third hole transport layer 27 stacked sequentially) are removed by etching or scraping, so that the area on the conductive plane of the ITO conductive glass where the third metal electrode is to be disposed is exposed, thereby forming the third metal electrode.

[0066] The two chlorine atoms in the 1,4-disubstituted fullerene provided in this application can react with Pb in the third perovskite active material. 2+ The coordination of chlorine atoms in the third perovskite active layer 26, thereby achieving a dual-site passivation effect, promotes crystal growth, facilitates charge extraction and transport in the third perovskite active layer 26, and reduces non-radiative recombination losses. Furthermore, the third electron transport layer 25 is typically made of a metal oxide, and chlorine atoms can coordinate with this metal oxide to reduce oxygen vacancies, thus suppressing interface defects caused by oxygen vacancies and enhancing the interface modification function of the functional layer. These two aspects combined contribute to improving the photoelectric conversion efficiency and device stability of perovskite solar cells.

[0067] To further improve the passivation effect of the functional layer and further reduce the oxygen vacancies on the third electron transport layer 25, thereby further improving the photoelectric conversion efficiency and device stability of the perovskite solar cell, preferably, when the material of the third perovskite active layer 26 is a mixture of 1,4-disubstituted fullerene and the third perovskite active material, the doping amount of 1,4-disubstituted fullerene is 0.04 to 0.06 wt% based on the weight percentage of the third perovskite active layer 26.

[0068] To further improve the passivation effect of the functional layer and further reduce oxygen vacancies on the third electron transport layer 25, thereby further improving the photoelectric conversion efficiency and device stability of the perovskite solar cell, the thickness of the interface modification layer 29 is preferably 1-5 nm.

[0069] This application does not specifically limit the third transparent conductive substrate 24, as long as it has high light transmittance and good conductivity, it can be conductive glass coated with a metal oxide conductive film commonly used in the art. In a preferred embodiment, the third transparent conductive substrate 24 includes, but is not limited to, ITO conductive glass, FTO conductive glass, or AZO conductive glass.

[0070] The material of the third electron transport layer 25 can be a metal oxide commonly used in the art. In a preferred embodiment, the material of the third electron transport layer 25 includes, but is not limited to, one or more of SnO2, ZnO, and TiO2. Compared with other types, the conduction band values ​​of the materials of the third electron transport layer 25 of the above types are lower than those of the materials of the third perovskite active layer 26 (where the band gap of SnO2 is typically 3.0 to 4.5 eV, the band gap of ZnO is typically 3.2 eV, and the band gap of TiO2 is typically 3.0 to 3.2 eV), which is beneficial for the electrons generated by the absorption of photons by the third perovskite active layer 26 under sunlight to be injected into the third electron transport layer 25 through the functional layer, thereby improving the electron transport efficiency and thus improving the photocurrent and photoelectric conversion efficiency.

[0071] The third perovskite active material can be of types commonly used in the art. In a preferred embodiment, the material of the third perovskite active layer 26 includes, but is not limited to, ABX3, where A is CH3NH3. + NH=CHNH3 + Cs + 、or Rb + B is Pb 2+ Sn 2+ Or Ge 2+ X is Cl, Br, I, or SCN. - or COO - .

[0072] The material of the third hole transport layer 27 can be of commonly used types in the art. In a preferred embodiment, the material of the third hole transport layer 27 includes, but is not limited to, one or more of nickel oxide, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), and 2,2',7,7'-tetratetra(N,N-di(4-methoxyphenyl)amino)-9,9'-spirodifluorene (Spiro-OMeTAD). Among these, nickel oxide NiO... x It has a high hole mobility (approximately 0.141 cm). 2 V -1 s -1 PTAA, with its wide bandgap, is beneficial as a material for the third hole transport layer 27, helping to suppress charge recombination and improve hole extraction efficiency, thereby enhancing the photoelectric conversion efficiency of perovskite solar cells. The hole mobility of PTAA is approximately 1 × 10⁻⁶. -2 cm 2 ·V -1 ·s -1 The hole mobility of Spiro-OMeTAD is approximately 1×10⁻⁶. -4 cm 2 ·V -1 ·s -1Materials that can be matched with the different types of third electron transport layer 25 mentioned above.

[0073] The material of the third metal electrode layer 28 can be a metal material commonly used in the art. In a preferred embodiment, the material of the third metal electrode layer 28 includes, but is not limited to, one or more of Au, Ag, Cu, and Al.

[0074] A third aspect of this application also provides a tandem solar cell, which consists of a perovskite solar top cell and a crystalline silicon solar bottom cell stacked together. The perovskite solar top cell is the perovskite solar cell described above in this application, and the crystalline silicon solar bottom cell is an HJT (intrinsic thin-film heterojunction cell), TOPCon (oxide-passivated contact cell), PERC (emitter and back passivated cell), IBC (interdigitated back contact cell), or HBC (ultra-high efficiency heterojunction back contact cell). The perovskite solar cell described above in this application has excellent photoelectric conversion efficiency and stability. Stacking it with a crystalline silicon solar cell to obtain a tandem solar cell can improve the photoelectric conversion efficiency and stability of the tandem solar cell.

[0075] A fourth aspect of this application also provides a method for preparing 1,4-disubstituted fullerenes, the method comprising:

[0076] Step S1, make C 60 An aluminum chloride-induced hydrogen aromatization reaction is carried out with the first solvent to obtain an intermediate having the structure shown in formula (II);

[0077]

[0078] Its synthetic route is as follows:

[0079] The first solvent includes chlorobenzene;

[0080] Step S2 involves the intermediate undergoing an oxidative arylation reaction with a second solvent and an oxidant under the catalysis of a catalyst to yield 1,4-disubstituted fullerenes; the synthetic route is as follows:

[0081] The second solvent includes chlorobenzene.

[0082] In a preferred embodiment, in step S2, the molar ratio of the intermediate to chlorobenzene in the second solvent is 1:10; preferably, the molar ratio of the intermediate to the catalyst is 1:0.1; preferably, the molar ratio of the intermediate to the oxidant is 1:2.5; preferably, the catalyst is trifluoromethanesulfonic acid; preferably, the oxidant is tetrachloro-o-benzoquinone. Using the above process parameters is beneficial for improving raw material utilization and for increasing the purity and yield of 1,4-disubstituted fullerenes.

[0083] In a preferred embodiment, the oxidative arylation reaction is carried out at a temperature of 100°C for 24 hours. The temperature and time of the oxidative arylation reaction include, but are not limited to, the ranges described above. Limiting them to these ranges is beneficial for further improving the yield of the subsequently obtained 1,4-disubstituted fullerenes.

[0084] In a preferred embodiment, in step S1, C 60 The molar ratio of aluminum chloride to chlorobenzene in the first solvent is 1:1; preferably, aluminum chloride and C 60 The molar ratio is 5:1; preferably, the first solvent is a mixture of chlorobenzene and water with a molar ratio of 1:1. Using the above process parameters is beneficial for increasing the formation rate of the intermediate, thereby improving the yield of the subsequently obtained 1,4-disubstituted fullerene.

[0085] In a preferred embodiment, the hydrogenation reaction is carried out at a temperature of 25°C for 2 hours. The temperature and time of the hydrogenation reaction include, but are not limited to, the ranges described above. Limiting the temperature and time to these ranges is beneficial for increasing the formation rate of the intermediate, thereby increasing the yield of the subsequently obtained 1,4-disubstituted fullerene.

[0086] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0087] Example 1

[0088] A method for fabricating a pin-type perovskite solar cell includes the following steps:

[0089] (1) Prepare clean ITO conductive glass (purchased from Advanced Election Technology Co., Ltd., sheet resistance is 7Ω / sq);

[0090] (2) Preparation of solution:

[0091] Preparation of the first hole transport material dispersion: NiO x The nanoparticles were dissolved in deionized water to form a dispersion with a mass concentration of 10 mg / mL, and then sonicated for 5 min.

[0092] Preparation of the first perovskite active material precursor solution: 507 mg of PbI2 and 159 mg of MAI were dissolved in DMF:DMSO (volume ratio 7:3) and stirred at 60°C for 4 h; then 0.05 wt% of chlorobenzene solution of 1-chlorophenyl-4-(4-chlorophenyl)

[60] fullerene was added, and the solution was shaken to dissolve, thus obtaining the first perovskite active material precursor solution;

[0093] Preparation of the first electron transport material dispersion: 20 mg PCBM was dispersed in chlorobenzene to form a dispersion with a mass concentration of 20 mg / mL, and stirred at 25 °C for 4 h.

[0094] The dispersion of the first cathode buffer material is an isopropanol solution of copper oxychloride (BCP) (BCP, 0.5 mg / mL);

[0095] (3) Fabrication of perovskite solar cell devices:

[0096] The first hole transport material dispersion was spin-coated onto the conductive surface of ITO conductive glass at a speed of 4000 rpm for 30 s, and then heated at 250 °C for 60 min to obtain NiO. x Hole transport layer;

[0097] Inside the glove box, a mixture of 20 μL of PbI2 and MAI was spin-coated onto NiO at 4000 rpm. x On the surface of the hole transport layer, spin coating time is 30s, 100μL of chlorobenzene solution is added dropwise at 20s for extraction, and heated at 100℃ for 10min to obtain MAPbI3 active layer doped with 1-chlorophenyl-4-(4-chlorophenyl)

[60] fullerene.

[0098] The PCBM dispersion was spin-coated at 2000 rpm onto the surface of the MAPbI3 active layer doped with 1-chlorophenyl-4-(4-chlorophenyl)

[60] fullerene for 30 s to obtain the PCBM electron transport layer.

[0099] BCP was spin-coated onto the electron transport layer surface of the PCBM at a speed of 4000 rpm for 30 s to obtain the BCP cathode buffer layer, thus obtaining the first stacked structure (ITO / NiO). x Hole transport layer / MAPbI3 active layer of 1-chlorophenyl-4-(4-chlorophenyl)

[60] fullerene / PCBM electron transport layer / BCP cathode buffer layer);

[0100] The layers of the ITO conductive glass surface in the above-mentioned stacked structure are removed by scraping, so that the area on the conductive plane of the ITO conductive glass where the silver metal electrode is to be placed is exposed, so as to form the silver metal electrode and obtain the second stacked structure.

[0101] The second layer structure described above is placed inside a photomask and transferred to a coating machine to... Ag was deposited at a high rate to obtain an 80 nm thick Ag metal electrode layer, thus completing the fabrication of a pin-type perovskite solar cell, the structure of which is as follows. Figure 1 As shown.

[0102] Example 2

[0103] A method for fabricating a pin-type perovskite solar cell includes the following steps:

[0104] (1) Same as step (1) in Example 1;

[0105] (2) Preparation of solution:

[0106] Preparation of the second hole transport material dispersion: NiO x The nanoparticles were dissolved in deionized water to form a dispersion with a mass concentration of 10 mg / mL, and then sonicated for 5 min.

[0107] Preparation of the second perovskite active material precursor solution: 507 mg of PbI2 and 159 mg of MAI were dissolved in DMF:DMSO (volume ratio 7:3) and stirred at 60°C for 4 h; then 0.05 wt% of chlorobenzene solution of 1-chlorophenyl-4-(4-chlorophenyl)

[60] fullerene was added, and the solution was shaken to dissolve, thus obtaining the second perovskite active material precursor solution;

[0108] Preparation of 1,4-disubstituted fullerene dispersion: 1-chlorophenyl-4-(4-chlorophenyl)

[60] fullerene was dispersed in o-dichlorobenzene to obtain a 1,4-disubstituted fullerene dispersion with a mass concentration of 5 mg / mL.

[0109] Preparation of the second electron transport material dispersion: 20 mg PCBM was dispersed in chlorobenzene to form a dispersion with a mass concentration of 20 mg / mL, and stirred at 25 °C for 4 h.

[0110] The dispersion of the second cathode buffer material is an isopropanol solution of copper oxychloride (BCP) (BCP, 0.5 mg / mL);

[0111] (3) Fabrication of perovskite solar cell devices:

[0112] The first hole transport material dispersion was spin-coated onto the conductive surface of ITO conductive glass at a speed of 4000 rpm for 30 s, and then heated at 250 °C for 60 min to obtain NiO. x Hole transport layer;

[0113] Inside the glove box, a mixture of 20 μL of PbI2 and MAI was spin-coated onto NiO at 4000 rpm. x On the surface of the hole transport layer, a MAPbI3 active layer was obtained by rotating the layer and heating it at 100°C for 10 min.

[0114] 20 μL of 1,4-disubstituted fullerene dispersion was spin-coated onto the surface of the MAPbI3 active layer at a speed of 4000 rpm for 30 s. After annealing at 100 °C for 1 min, a passivation layer 23 with a thickness of 8 nm was obtained.

[0115] The PCBM dispersion was spin-coated onto the surface of the passivation layer 23 at a speed of 2000 rpm for 30 s to obtain the PCBM electron transport layer.

[0116] BCP was spin-coated onto the electron transport layer surface of the PCBM at a speed of 4000 rpm for 30 s to obtain the BCP cathode buffer layer, thus obtaining the third stacked structure (ITO / NiO). x Hole transport layer / MAPbI3 active layer / passivation layer 23 / PCBM electron transport layer / BCP cathode buffer layer);

[0117] The layers of the ITO conductive glass surface in the third stacked structure are removed by scraping, so that the area on the conductive plane of the ITO conductive glass where the silver metal electrode is to be placed is exposed, so as to form the silver metal electrode and obtain the fourth stacked structure.

[0118] The aforementioned fourth-layer structure is placed inside a photomask and transferred to a coating machine to... Ag was deposited at a high rate to obtain an 80 nm thick Ag metal electrode layer, thus completing the fabrication of a pin-type perovskite solar cell, the structure of which is as follows. Figure 2 As shown.

[0119] Example 3

[0120] A method for fabricating a nip-type perovskite solar cell includes the following steps:

[0121] (1) Same as step (1) in Example 1;

[0122] (2) Preparation of solution:

[0123] Preparation of 1,4-disubstituted fullerene dispersion: 1-chlorophenyl-4-(4-chlorophenyl)

[60] fullerene was dispersed in chlorobenzene to obtain a 1,4-disubstituted fullerene dispersion with a mass concentration of 0.5 mg / mL.

[0124] Preparation of the precursor solution of the third perovskite active material: 507 mg of PbI2 and 159 mg of MAI were dissolved in DMF:DMSO (volume ratio of 7:3) and stirred at 60°C for 4 h; then 0.05 wt% of chlorobenzene solution of 1-chlorophenyl-4-(4-chlorophenyl)

[60] fullerene was added, and the solution was shaken to dissolve, thus obtaining the precursor solution of the third perovskite active material.

[0125] The third hole transport material dispersion was a Spiro-OMeTAD solution (solvent: CB), wherein the mass concentration of Spiro-OMeTAD was 73.2 mg·mL⁻¹. -1 The mass concentration of tetra-tert-butylpyridine is 28.8 μL·mL. -1 18.8 μL·mL -1 Lithium salt Li-TFSI;

[0126] (3) Fabrication of perovskite solar cell devices:

[0127] A 2.67% SnO2 aqueous solution was spin-coated onto the conductive surface of ITO conductive glass at a speed of 4000 rpm for 30 s. The solution was then annealed at 170℃ for 30 min to obtain a SnO2 electron transport layer.

[0128] Inside a glove box, 20 μL of 1,4-disubstituted fullerene dispersion was spin-coated onto the surface of the SnO2 electron transport layer at a speed of 4000 rpm for 30 s to obtain interface modification layer 29; the thickness of the interface modification layer 29 was 3 nm.

[0129] A mixture of 20 μL of PbI2 and MAI was spin-coated onto the surface of the interface modification layer 29 at a speed of 4000 rpm and heated at 100 °C for 10 min to obtain the MAPbI3 active layer.

[0130] Spiro-OMeTAD solution was spin-coated onto a perovskite film at a speed of 3000 rpm. After spin-coating for 20 s, a Spiro-OMeTAD hole transport layer was obtained, resulting in the fifth layer stack structure (ITO / SnO2 electron transport layer / interface modification layer 29 / MAPbI3 active layer / Spiro-OMeTAD hole transport layer).

[0131] The layers of the ITO conductive glass surface in the fifth stacked structure are removed by scraping, so that the area on the conductive plane of the ITO conductive glass where the silver metal electrode is to be placed is exposed, so as to form the silver metal electrode and obtain the sixth stacked structure.

[0132] The aforementioned sixth-layer stacked structure is placed inside a photomask and transferred to a coating machine to... Ag was deposited at a high rate to obtain an Ag metal electrode layer with a thickness of 80 nm, thus completing the fabrication of a nip-type perovskite solar cell, the structure of which is as follows. Figure 3 As shown.

[0133] Example 4

[0134] The difference from Example 1 is that the first perovskite active material precursor solution contains 0.01 wt% of 1-chlorophenyl-4-(4-chlorophenyl)

[60] fullerene; the remaining steps are the same as in Example 1.

[0135] Example 5

[0136] The difference from Example 1 is that the first perovskite active material precursor solution contains 0.5 wt% of 1-chlorophenyl-4-(4-chlorophenyl)

[60] fullerene; the remaining steps are the same as in Example 1.

[0137] Example 6

[0138] The difference from Example 1 is that the first perovskite active material precursor solution contains 1.0 wt% of 1-chlorophenyl-4-(4-chlorophenyl)

[60] fullerene; the remaining steps are the same as in Example 1.

[0139] Example 7

[0140] A perovskite / HJT tandem solar cell is disclosed, comprising a perovskite solar top cell and a crystalline silicon solar bottom cell stacked together. The perovskite solar top cell is the perovskite solar cell prepared in Example 3, and the crystalline silicon solar bottom cell is an HJT (refer to the literature Monolithic perovskite / silicon tandem solar cell with >29% efficiency by enhanced hole extraction. Science, 370(6522), 1300-1309).

[0141] Example 8

[0142] A perovskite / TOPCon tandem solar cell is disclosed, comprising a perovskite solar top cell and a crystalline silicon solar bottom cell stacked together. The perovskite solar top cell is the perovskite solar cell prepared in Example 3, and the crystalline silicon solar bottom cell is TOPCon (refer to the literature Balancing charge-carrier transport and recombination for perovskite / TOPCon tandem solar cells with double-textured structures. Advanced Energy Materials, 2002, 2203006).

[0143] Comparative Example 1

[0144] The difference from Example 1 is that no fullerene derivative was introduced into the first perovskite active material precursor solution; the remaining steps are the same as in Example 1.

[0145] Comparative Example 2

[0146] The difference from Example 1 is that the 1-chlorophenyl-4-(4-chlorophenyl)

[60] fullerene in Example 1 is replaced with a fullerene derivative with the following structure: The remaining steps are the same as in Example 1.

[0147] The solar cells prepared in Examples 1 to 8 and Comparative Examples 1 and 2 of this application were placed at 100mW / cm². 2 Under illumination, their photovoltaic performance was tested, and Table 1 lists the photovoltaic parameters of the solar cells prepared in the corresponding embodiments or comparative examples.

[0148] Table 1

[0149]

[0150]

[0151] The solar cells prepared in Examples 1 to 8 and Comparative Examples 1 and 2 of this application were placed in a nitrogen atmosphere and 60% humidity environment for 500 hours to test their device stability. The solar cells were all in a dark environment during the test. The normalized test results are shown in Table 2.

[0152] Table 2

[0153] Example 1 0.97 0.82 Example 2 0.99 0.85 Example 3 0.95 0.78 Example 4 0.92 0.80 Example 5 0.94 0.77 Example 6 0.88 0.69 Example 7 0.95 0.78 Example 8 0.94 0.76 Comparative Example 1 0.84 0.65 Comparative Example 2 0.96 0.80

[0154] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0155] Comparing Examples 1 to 3 and Comparative Example 1, it can be seen that 1-chlorophenyl-4-(4-chlorophenyl)

[60] fullerene, as a fullerene derivative, can be introduced into perovskite solar cells as an additive. On the one hand, it can improve the electron extraction efficiency and make the transmission of electrons and holes more balanced. On the other hand, when the above fullerene derivative is applied to perovskite solar cells, it can effectively passivate the defects in the perovskite active layer itself, effectively regulate the crystallization of perovskite active materials, suppress phase separation, and thus improve the photoelectric conversion efficiency and stability of perovskite solar cells.

[0156] Comparing Example 1 and Comparative Example 2, it can be seen that, compared to one chlorine atom, the C in the chemical structure of 1-chlorophenyl-4-(4-chlorophenyl)

[60] fullerene is significantly different. 60Each of the two substituents contains a chlorine atom, thus its application in perovskite solar cells can achieve multi-site chlorine passivation, reducing uncoordinated Pb. 2+ Ion defects and oxygen vacancies create interfacial defects, thereby improving the photoelectric conversion efficiency and stability of perovskite solar cells while exerting their passivation effect.

[0157] Comparing Examples 1, 4 to 6, it can be seen that, compared with other ranges, limiting the doping amount of 1-chlorophenyl-4-(4-chlorophenyl)

[60] fullerene to the preferred range of this application is beneficial to further improve the electron extraction efficiency and further suppress the phase separation phenomenon, thereby further improving the photoelectric conversion efficiency and stability of pin-type perovskite solar cells.

[0158] It should be noted that the terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in a sequence other than those described herein.

[0159] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An application of a 1,4-disubstituted fullerene in perovskite solar cells, characterized in that, The 1,4-disubstituted fullerene is 1-chlorophenyl-4-(4-chlorophenyl)[60]fullerene, which has the structure shown in formula (I): （I）。 2. A perovskite solar cell, characterized in that, The perovskite solar cell includes a functional layer containing a fullerene derivative, wherein the fullerene derivative is a 1,4-disubstituted fullerene, and the 1,4-disubstituted fullerene is a 1-chlorophenyl-4-(4-chlorophenyl)[60] fullerene having the structure shown in formula (I): （I）。 3. The perovskite solar cell according to claim 2, characterized in that, The perovskite solar cell is a pin-type perovskite solar cell.

4. The perovskite solar cell according to claim 3, characterized in that, The perovskite solar cell includes a first transparent conductive substrate (11), a first hole transport layer (12), the functional layer, a first electron transport layer (13), and a first cathode buffer layer (14) stacked sequentially. The perovskite solar cell also includes a first metal electrode layer, which includes a plurality of first metal electrodes (15). A portion of the first metal electrodes (15) are disposed on the side surface of the first cathode buffer layer (14) away from the first electron transport layer (13), and a portion of the first metal electrodes (15) are disposed on the conductive surface of the first transparent conductive substrate (11). The functional layer is the first perovskite active layer (16) doped with 1,4-disubstituted fullerene.

5. The perovskite solar cell according to claim 4, characterized in that, The amount of 1,4-disubstituted fullerene doped is 0.01 to 0.5 wt% based on the weight percentage of the first perovskite active layer (16).

6. The perovskite solar cell according to claim 5, characterized in that, The amount of 1,4-disubstituted fullerene doped is 0.04 to 0.06 wt% based on the weight percentage of the first perovskite active layer (16).

7. The perovskite solar cell according to claim 4, characterized in that, The first transparent conductive substrate (11) is selected from ITO conductive glass, FTO conductive glass, or AZO conductive glass; and / or, the material of the first hole transport layer (12) is selected from one or more of nickel oxide, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], and [2-(9H-carbazole-9-yl)ethyl]phosphoric acid; and / or, the material of the first perovskite active layer (16) is selected from ABX3, wherein A is CH3NH3. + NH=CHNH3 + Cs + 、or Rb + B is Pb 2+ Sn 2+ Or Ge 2+ X is Cl, Br, I, or SCN. - or COO - ; and / or, the material of the first electron transport layer (13) is selected from SnO2, ZnO, C 60 One or more of PCBM; and / or, the material of the first cathode buffer layer (14) is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline; and / or, the material of the first metal electrode layer (15) is selected from one or more of Au, Ag, Cu, and Al.

8. The perovskite solar cell according to claim 3, characterized in that, The perovskite solar cell comprises a second transparent conductive substrate (17), a second hole transport layer (18), a second perovskite active layer (19), the functional layer, a second electron transport layer (20), and a second cathode buffer layer (21) stacked sequentially. The perovskite solar cell also includes a second metal electrode layer, which comprises a plurality of second metal electrodes (22). A portion of the second metal electrodes (22) are disposed on the side surface of the second cathode buffer layer (21) away from the second electron transport layer (20), and a portion of the second metal electrodes (22) are disposed on the conductive surface of the second transparent conductive substrate (17). The functional layer is a passivation layer (23) composed of the 1,4-disubstituted fullerene. The material of the second perovskite active layer (19) is a second perovskite active material or a mixture of the 1,4-disubstituted fullerene and the second perovskite active material.

9. The perovskite solar cell according to claim 8, characterized in that, The passivation layer (23) has a thickness of 10-20 nm.

10. The perovskite solar cell according to claim 8, characterized in that, The material of the second perovskite active layer (19) is a mixture of the 1,4-disubstituted fullerene and the second perovskite active material. The doping amount of the 1,4-disubstituted fullerene is 0.04 to 0.06 wt% based on the weight percentage of the second perovskite active layer (19).

11. The perovskite solar cell according to claim 8, characterized in that, The second transparent conductive substrate (17) is selected from ITO conductive glass, FTO conductive glass, or AZO conductive glass; and / or, the material of the second hole transport layer (18) is selected from one or more of nickel oxide, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], and [2-(9H-carbazole-9-yl)ethyl]phosphoric acid; and / or, the material of the second perovskite active layer (19) is selected from ABX3, wherein A is CH3NH3. + NH=CHNH3 + Cs + 、or Rb + B is Pb 2+ Sn 2+ Or Ge 2+ X is Cl, Br, I, or SCN. - or COO - ; and / or, the material of the second electron transport layer (20) is independently selected from SnO2, ZnO, C 60 One or more of PCBM; and / or, the material of the second cathode buffer layer (21) is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline; and / or, the material of the second metal electrode layer (22) is selected from one or more of Au, Ag, Cu, and Al.

12. The perovskite solar cell according to claim 2, characterized in that, The perovskite solar cell is a nip-type perovskite solar cell.

13. The perovskite solar cell according to claim 12, characterized in that, The perovskite solar cell comprises a third transparent conductive substrate (24), a third electron transport layer (25), the functional layer, a third perovskite active layer (26), and a third hole transport layer (27) stacked sequentially. The perovskite solar cell also includes a third metal electrode layer, which comprises a plurality of third metal electrodes (28). A portion of the third metal electrodes (28) are disposed on the surface of the third hole transport layer (27) away from the third perovskite active layer (26), and a portion of the third metal electrodes (28) are disposed on the conductive surface of the third transparent conductive substrate (24). The functional layer is an interface modification layer (29), the material of which is the 1,4-disubstituted fullerene. The material of the third perovskite active layer (26) is a third perovskite active material or a mixture of the 1,4-disubstituted fullerene and the third perovskite active material.

14. The perovskite solar cell according to claim 13, characterized in that, The thickness of the interface modification layer (29) is 1-5 nm.

15. The perovskite solar cell according to claim 13, characterized in that, The third transparent conductive substrate (24) is selected from ITO conductive glass, FTO conductive glass or AZO conductive glass; the material of the third electron transport layer (25) is selected from one or more of SnO2, ZnO, TiO2; and / or, the material of the third perovskite active layer (26) is selected from ABX3, where A is CH3NH3. + NH=CHNH3 + Cs + 、or Rb + B is Pb 2+ Sn 2+ Or Ge 2+ X is Cl, Br, I, or SCN. - or COO - ; and / or, the material of the third hole transport layer (27) is selected from one or more of nickel oxide, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], and 2,2',7,7'-tetratetra(N,N-di(4-methoxyphenyl)amino)-9,9'-spirodifluorene; and / or, the material of the third metal electrode layer (28) is selected from one or more of Au, Ag, Cu, and Al.

16. The perovskite solar cell according to claim 13, characterized in that, The material of the third perovskite active layer (26) is a mixture of the 1,4-disubstituted fullerene and the third perovskite active material. The doping amount of the 1,4-disubstituted fullerene is 0.04 to 0.06 wt% based on the weight percentage of the third perovskite active layer (26).

17. A tandem solar cell, characterized in that, The tandem solar cell is a perovskite solar top cell and a crystalline silicon solar bottom cell stacked together. The perovskite solar top cell is a perovskite solar cell according to any one of claims 2 to 16, and the crystalline silicon solar bottom cell is HJT, TOPCon, PERC, IBC or HBC.

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