Perovskite solar cells and their fabrication methods

Abstract

This application provides a perovskite solar cell and its fabrication method, belonging to the field of perovskite solar cell technology. The perovskite solar cell comprises a conductive substrate, a hole transport layer, an interface modification layer, and a perovskite layer stacked sequentially; the conductive substrate comprises a metal oxide; the hole transport layer comprises self-assembled monomolecules; the perovskite layer comprises a perovskite material; and the perovskite material comprises Pb. 2+ The interface modification layer includes an interface modifier having the structure shown in Formula I. This application, by employing an interface modifier having the structure shown in Formula I, can significantly improve the interface defects between the hole transport layer and the perovskite layer, thereby enhancing the performance of perovskite solar cells.

Description

Technical Field

[0001] This application relates to the field of perovskite battery technology, and in particular to perovskite solar cells and their fabrication methods. Background Technology

[0002] Perovskite solar cells have become a research hotspot in next-generation photovoltaic technology due to their high photoelectric conversion efficiency, low raw material costs, and simple solution-based fabrication process. However, the interface problem between the perovskite active layer and the charge transport layer, especially the interface problem between the hole transport layer (HTL) and the perovskite layer, remains a key bottleneck restricting further performance improvement and industrialization in perovskite solar cells.

[0003] Currently, compared with traditional polymer hole transport materials (such as Spiro-OMeTAD), self-assembled monolayers (SAMs) have advantages such as low material consumption, tunable energy levels, and simple preparation, and can be used to improve the interface between hole transport layers and perovskite layers. However, the density and uniformity of the hole transport layer formed by SAM molecules still need to be further improved. At the same time, problems such as interfacial energy level mismatch and charge recombination still exist between the hole transport layer and the perovskite layer. Summary of the Invention

[0004] Based on this, the main objective of this application is to provide a perovskite solar cell and a method for its fabrication, so as to improve the interface defects between the hole transport layer and the perovskite layer and enhance the performance of the perovskite solar cell.

[0005] In a first aspect, this application provides a perovskite solar cell comprising a conductive substrate, a hole transport layer, an interface modification layer, and a perovskite layer stacked sequentially.

[0006] The conductive substrate includes a metal oxide;

[0007] The hole transport layer comprises self-assembled monomolecules;

[0008] The perovskite layer comprises a perovskite material; the perovskite material comprises Pb. 2+ ;

[0009] The interface modification layer includes an interface modifier, which has the structure shown in Formula I:

[0010] Formula I;

[0011] Wherein, A includes an isothiocyanate group or an isocyanate group;

[0012] n represents the number of CF3s, and n can be 1-2.

[0013] In some embodiments, the interface modifier comprises at least one of the structures shown in the following formula:

[0014] .

[0015] In some embodiments, the self-assembled monomolecule includes at least one of silane-based self-assembled monomolecules, phosphate-based self-assembled monomolecules, and thiol-based self-assembled monomolecules.

[0016] In some embodiments, the phosphate self-assembled monomolecules include [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphate, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphate, [3-(3,6-dimethoxy-9H-carbazole-9-yl)propyl]phosphate, [6-(3,6-dimethoxy-9H-carbazole-9-yl)hexyl]phosphate, [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphate, [3-(3,6-dimethyl-9H-carbazole-9-yl)propyl]phosphate, [6-(3,6-dimethyl-9H-carbazole-9-yl)hexyl]phosphate, [1-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphate, [4-(3,6-dimethoxy-9H-carbazole-9-yl)propyl]phosphate, [6-(3,6-dimethyl-9H-carbazole-9-yl)hexyl]phosphate, [6-(3,6-dimethyl-9H-carbazole-9-yl)ethyl ... [9-yl)methyl]phosphoric acid, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphoric acid, [8-(3,6-dimethyl-9H-carbazole-9-yl)octyl]phosphoric acid, [1-(9H-carbazole-9-yl)methyl]phosphoric acid, [2-(9H-carbazole-9-yl)ethyl]phosphoric acid, [3-(9H-carbazole-9-yl)propyl]phosphoric acid, [4-(9H-carbazole-9-yl)butyl]phosphoric acid, [6-(9H-carbazole-9-yl)hexyl]phosphoric acid, [8-(9H-carbazole-9-yl)octyl]phosphoric acid, [4-(N,N-di(4-methoxyphenylamino)phenyl)propyl]phosphoric acid, 2,3,4,5,6-pentafluorobenzylphosphoric acid, [2-(9H-9-yl)methyl ...4-(N,N-di(4-methoxyphenylamino)phenyl)propyl]phosphoric acid, 2,3,4,5,6-pentafluorobenzylphosphoric acid, [4-(N,N-di ， -Phenyl-3,3 ， -Dicarbazole-9-yl)ethyl]phosphoric acid, [4-(9H-9] ， -Phenyl-3,3 ，[-di-carbazole-9-yl)butyl]phosphate, [4-(diphenylamino)phenethyl]phosphate, [(4-(diphenylamino)phenyl)propyl]phosphate, [4-(10H-phenthiazin-10-yl)butyl]phosphate, [2-(7H-dibenzocarbazole-7-yl)ethyl]phosphate, [4-(7H-dibenzocarbazole-7-yl)butyl]phosphate, [3-(3,6-dibromo-9H-carbazole-9-yl)propyl]phosphate, [4-(3,6-di-di-carbazole-9-yl)propyl]phosphate, [4-(3,6-di-di-carbazole-9-yl)ethyl ... [bromo-9H-carbazole-9-yl)butyl]phosphoric acid, [6-(3,6-dibromo-9H-carbazole-9-yl)hexyl]phosphoric acid, [1-(3,6-di-tert-butyl-9H-carbazole-9-yl)methyl]phosphoric acid, [2-(3,6-di-tert-butyl-9H-carbazole-9-yl)ethyl]phosphoric acid, [3-(3,6-di-tert-butyl-9H-carbazole-9-yl)propyl]phosphoric acid, [4-(3,6-di-tert-butyl-9H-carbazole-9-yl)butyl]phosphoric acid Acid, [6-(3,6-di-tert-butyl-9H-carbazole-9-yl)hexyl]phosphoric acid, [8-(3,6-di-tert-butyl-9H-carbazole-9-yl)octyl]phosphoric acid, [1-(3,6-diphenyl-9H-carbazole-9-yl)methyl]phosphoric acid, [2-(3,6-diphenyl-9H-carbazole-9-yl)ethyl]phosphoric acid, [3-(3,6-diphenyl-9H-carbazole-9-yl)propyl]phosphoric acid, [4-(3,6-diphenyl-9H-carbazole-9-yl)... At least one of the following: [-carbazole-9-yl)butyl]phosphoric acid, [6-(3,6-diphenyl-9H-carbazole-9-yl)hexyl]phosphoric acid, [8-(3,6-diphenyl-9H-carbazole-9-yl)octyl]phosphoric acid, [2-(10H-phenoxazine-10-yl)ethyl]phosphoric acid, [4-(3,7-dibromo-10H-phenthiazine-10-yl)butyl]phosphoric acid, and [4-(3,7-dibromo-10H-phenoxazine-10-yl)butyl]phosphoric acid.

[0017] In some embodiments, the perovskite material comprises ABX3; wherein A comprises FA. + Cs + and MA + At least one of them; B includes Pb 2+ Or, Pb 2+ and Sn 2+ ;X includes I - ,Br - and Cl - At least one of them.

[0018] In some embodiments, the perovskite material includes FAPbI3.

[0019] In some embodiments, the thickness of the interface modification layer is 1 nm to 5 nm.

[0020] In some embodiments, the perovskite solar cell further includes an electron transport layer, a buffer layer, and an electrode layer stacked sequentially; the electron transport layer is disposed between the perovskite layer and the buffer layer.

[0021] A second aspect of this application provides a method for fabricating the perovskite solar cell described in the first aspect, comprising the following steps:

[0022] A hole transport layer, an interface modification layer, and a perovskite layer are sequentially prepared on a conductive substrate.

[0023] In some embodiments, the step of sequentially fabricating a hole transport layer, an interface modification layer, and a perovskite layer on a conductive substrate includes:

[0024] A hole transport layer, an interface modification layer, and a perovskite layer were sequentially prepared on a conductive substrate using a wet deposition process.

[0025] Compared with traditional technologies, this application has at least the following beneficial effects:

[0026] The interface modification layer used in this application can improve the open-circuit voltage and fill factor of perovskite solar cells, reduce energy loss, and improve the overall photoelectric conversion efficiency and stability of the device. Specifically, an interface modifier with the structure shown in Formula I is employed. Highly reactive isothiocyanate groups or isocyanate groups can coordinate with regions not covered by self-assembled monomolecules on the conductive substrate, effectively passivating vacancies and defects on the metal oxide surface, reducing non-radiative recombination paths at the interface, and achieving interface passivation by combining with unsaturated lead ions in the perovskite. Simultaneously, the strongly electron-withdrawing trifluoromethyl group can construct a dipole field at the interface, enabling the regulation of the work function of the hole transport layer, improving its matching degree with the perovskite valence band energy level. Furthermore, the hydrophobic properties of trifluoromethyl can inhibit ion migration and water / oxygen intrusion in the perovskite layer, improving the long-term stability of the device under conditions such as light and humidity. Attached Figure Description

[0027] To better describe and illustrate the embodiments or examples provided in this application, reference may be made to one or more accompanying drawings. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed applications, the currently described embodiments or examples, or the best mode of conduct of these applications as currently understood. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0028] Figure 1 This is a schematic diagram of the structure of a perovskite solar cell;

[0029] Figure 2 This is a schematic diagram showing the stability test results of the perovskite solar cells prepared in Comparative Example 2 and Example 1. Detailed Implementation

[0030] The present application will be further described in detail below with reference to the embodiments and examples. These embodiments and examples are only for illustrating the present application and are not intended to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the disclosure of the present application more thorough and comprehensive. It should also be understood that the present application can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various modifications or alterations without departing from the spirit of the present application, and the equivalent forms obtained also fall within the protection scope of the present application. In addition, numerous specific details are set forth in the following description to provide a fuller understanding of the present application. It should be understood that the present application can be implemented without one or more of these details.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] To address the interface problem between the perovskite active layer and the charge transport layer, this application introduces an interface modifier with the structure shown in Formula I between the perovskite layer and the hole transport layer. The highly reactive isothiocyanate group or isocyanate group can coordinate with regions not covered by self-assembled monomolecules on the conductive substrate, effectively passivating vacancies and defects on the metal oxide surface, reducing non-radiative recombination paths at the interface, and achieving interface passivation by combining with unsaturated lead ions in the perovskite. Simultaneously, the strongly electron-withdrawing trifluoromethyl group can construct a dipole field at the interface, enabling the regulation of the work function of the hole transport layer, improving its matching degree with the perovskite valence band energy level. Furthermore, the hydrophobic properties of trifluoromethyl can suppress ion migration and water / oxygen intrusion in the perovskite layer, improving the long-term stability of the device under conditions such as light and humidity.

[0033] In a first aspect, this application provides a perovskite solar cell comprising a conductive substrate, a hole transport layer, an interface modification layer, and a perovskite layer stacked sequentially.

[0034] The conductive substrate includes a metal oxide;

[0035] The hole transport layer comprises self-assembled monomolecules;

[0036] The perovskite layer comprises a perovskite material; the perovskite material comprises Pb. 2+ ;

[0037] The interface modification layer includes an interface modifier, which has the structure shown in Formula I:

[0038] Formula I;

[0039] Wherein, A includes an isothiocyanate group or an isocyanate group;

[0040] n represents the number of CF3s, and n can be 1-2.

[0041] In this application, the interface modifier has highly reactive isothiocyanate groups or isocyanate groups, which can coordinate with the regions not covered by self-assembled monomolecules on the conductive substrate, effectively passivating vacancies and defects on the surface of metal oxides, reducing non-radiative recombination pathways at the interface, and achieving interface passivation by combining with unsaturated lead ions in the perovskite. At the same time, the strong electron-withdrawing trifluoromethyl group can construct a dipole field at the interface, thereby controlling the work function of the hole transport layer and improving its matching degree with the valence band energy level of the perovskite. Furthermore, the hydrophobic properties of trifluoromethyl can inhibit ion migration and water and oxygen intrusion in the perovskite layer, improving the long-term stability of the device under conditions such as light and humidity, and enhancing the performance of perovskite solar cells.

[0042] In some embodiments, the interface modifier comprises at least one of the structures shown in the following formula:

[0043] .

[0044] In some embodiments, the interface modifier is 3,5-bis(trifluoromethyl)phenyl isothiocyanate, 3,5-bis(trifluoromethyl)phenyl isocyanate, or 4-(trifluoromethyl)phenyl isothiocyanate.

[0045] In some embodiments, the interface modifier is 3,5-bis(trifluoromethyl)phenyl isothiocyanate or 3,5-bis(trifluoromethyl)phenyl isocyanate.

[0046] The interface modifier 3,5-bis(trifluoromethyl)phenyl isothiocyanate or 3,5-bis(trifluoromethyl)phenyl isocyanate utilizes the symmetrical structure of the two strongly electron-withdrawing trifluoromethyl groups in the molecule to form a uniformly oriented molecular dipole layer at the interface. This dipole layer can significantly optimize the interface energy level arrangement, effectively reduce the work function of the hole transport layer, and reduce the hole extraction barrier. At the same time, it constructs a highly efficient electron blocking layer, which greatly suppresses electron leakage, thereby significantly improving the open-circuit voltage and fill factor of the device, and thus improving the device efficiency.

[0047] In some embodiments, the interface modifier is 3,5-bis(trifluoromethyl)phenyl isothiocyanate. Using 3,5-bis(trifluoromethyl)phenyl isothiocyanate as an interface modifier can simultaneously achieve robust interfacial chemical bonding, precise interfacial energy level modulation, and deep perovskite surface defect passivation, which is of crucial significance for overcoming the performance bottlenecks of perovskite solar cells.

[0048] In some embodiments, the self-assembled monomolecule includes at least one of silane-based self-assembled monomolecules, phosphate-based self-assembled monomolecules, and thiol-based self-assembled monomolecules.

[0049] In some embodiments, the phosphate self-assembled monomolecules include [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphate, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphate, [3-(3,6-dimethoxy-9H-carbazole-9-yl)propyl]phosphate, [6-(3,6-dimethoxy-9H-carbazole-9-yl)hexyl]phosphate, [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphate, [3-(3,6-dimethyl-9H-carbazole-9-yl)propyl]phosphate, [6-(3,6-dimethyl-9H-carbazole-9-yl)hexyl]phosphate, [1-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphate, [4-(3,6-dimethoxy-9H-carbazole-9-yl)propyl]phosphate, [6-(3,6-dimethyl-9H-carbazole-9-yl)hexyl]phosphate, [6-(3,6-dimethyl-9H-carbazole-9-yl)ethyl ... [9-yl)methyl]phosphoric acid, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphoric acid, [8-(3,6-dimethyl-9H-carbazole-9-yl)octyl]phosphoric acid, [1-(9H-carbazole-9-yl)methyl]phosphoric acid, [2-(9H-carbazole-9-yl)ethyl]phosphoric acid, [3-(9H-carbazole-9-yl)propyl]phosphoric acid, [4-(9H-carbazole-9-yl)butyl]phosphoric acid, [6-(9H-carbazole-9-yl)hexyl]phosphoric acid, [8-(9H-carbazole-9-yl)octyl]phosphoric acid, [4-(N,N-di(4-methoxyphenylamino)phenyl)propyl]phosphoric acid, 2,3,4,5,6-pentafluorobenzylphosphoric acid, [2-(9H-9-yl)methyl ...4-(N,N-di(4-methoxyphenylamino)phenyl)propyl]phosphoric acid, 2,3,4,5,6-pentafluorobenzylphosphoric acid, [4-(N,N-di ， -Phenyl-3,3 ， -Dicarbazole-9-yl)ethyl]phosphoric acid, [4-(9H-9] ， -Phenyl-3,3 ，[-di-carbazole-9-yl)butyl]phosphate, [4-(diphenylamino)phenethyl]phosphate, [(4-(diphenylamino)phenyl)propyl]phosphate, [4-(10H-phenthiazin-10-yl)butyl]phosphate, [2-(7H-dibenzocarbazole-7-yl)ethyl]phosphate, [4-(7H-dibenzocarbazole-7-yl)butyl]phosphate, [3-(3,6-dibromo-9H-carbazole-9-yl)propyl]phosphate, [4-(3,6-di-di-carbazole-9-yl)propyl]phosphate, [4-(3,6-di-di-carbazole-9-yl)ethyl ... [bromo-9H-carbazole-9-yl)butyl]phosphoric acid, [6-(3,6-dibromo-9H-carbazole-9-yl)hexyl]phosphoric acid, [1-(3,6-di-tert-butyl-9H-carbazole-9-yl)methyl]phosphoric acid, [2-(3,6-di-tert-butyl-9H-carbazole-9-yl)ethyl]phosphoric acid, [3-(3,6-di-tert-butyl-9H-carbazole-9-yl)propyl]phosphoric acid, [4-(3,6-di-tert-butyl-9H-carbazole-9-yl)butyl]phosphoric acid Acid, [6-(3,6-di-tert-butyl-9H-carbazole-9-yl)hexyl]phosphoric acid, [8-(3,6-di-tert-butyl-9H-carbazole-9-yl)octyl]phosphoric acid, [1-(3,6-diphenyl-9H-carbazole-9-yl)methyl]phosphoric acid, [2-(3,6-diphenyl-9H-carbazole-9-yl)ethyl]phosphoric acid, [3-(3,6-diphenyl-9H-carbazole-9-yl)propyl]phosphoric acid, [4-(3,6-diphenyl-9H-carbazole-9-yl)... At least one of the following: [-carbazole-9-yl)butyl]phosphoric acid, [6-(3,6-diphenyl-9H-carbazole-9-yl)hexyl]phosphoric acid, [8-(3,6-diphenyl-9H-carbazole-9-yl)octyl]phosphoric acid, [2-(10H-phenoxazine-10-yl)ethyl]phosphoric acid, [4-(3,7-dibromo-10H-phenthiazine-10-yl)butyl]phosphoric acid, and [4-(3,7-dibromo-10H-phenoxazine-10-yl)butyl]phosphoric acid.

[0050] In some embodiments, the perovskite material comprises ABX3; wherein M comprises FA. + Cs + and MA + At least one of them; B includes Pb 2+ Or, Pb 2+ and Sn 2+ X includes I - ,Br - and Cl - At least one of them.

[0051] In some embodiments, the perovskite material comprises ABX3, wherein M comprises FA. + Cs + and MA + At least one of them, B includes Pb 2+ X includes I - ,Br- and Cl - At least one of them.

[0052] In some embodiments, the perovskite material includes FAPbI3.

[0053] In some embodiments, the thickness of the interface modification layer is 1nm-5nm, which can be 1nm, 2nm, 3nm, 4nm or 5nm.

[0054] In some embodiments, the conductive substrate includes one of fluorine tin oxide transparent conductive glass (FTO), indium tin oxide transparent conductive glass (ITO), indium tin oxide / polyethylene terephthalate (ITO / PET) film and indium tin oxide / polyethylene naphthalate (ITO / PEN) film.

[0055] In some embodiments, the perovskite solar cell further includes an electron transport layer, a buffer layer, and an electrode layer stacked sequentially; the electron transport layer is disposed between the perovskite layer and the buffer layer.

[0056] In some embodiments, the perovskite solar cell includes a conductive substrate, a hole transport layer, an interface modification layer, a perovskite layer, an electron transport layer, a buffer layer, and an electrode layer stacked sequentially.

[0057] The conductive substrate includes one of the following: fluorine tin oxide transparent conductive glass (FTO), indium tin oxide transparent conductive glass (ITO), indium tin oxide / polyethylene terephthalate (ITO / PET) film, and indium tin oxide / polyethylene naphthalate (ITO / PEN) film;

[0058] The electron transport layer comprises one of C60, methyl [6,6]-phenylC61 butyrate, and zinc oxide;

[0059] The buffer layer comprises 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline and / or tin dioxide (SnO2).

[0060] The electrode layer may be made of silver, copper, gold or carbon.

[0061] A second aspect of this application provides a method for fabricating the perovskite solar cell described in the first aspect, comprising the following steps:

[0062] A hole transport layer, an interface modification layer, and a perovskite layer are sequentially prepared on a conductive substrate.

[0063] In some embodiments, the step of sequentially fabricating a hole transport layer, an interface modification layer, and a perovskite layer on a conductive substrate includes:

[0064] A hole transport layer, an interface modification layer, and a perovskite layer were sequentially prepared on a conductive substrate using a wet deposition process.

[0065] In some embodiments, fabricating a hole transport layer on a conductive substrate specifically includes:

[0066] The hole transport layer was prepared by spin coating to deposit a self-assembled monomolecule solution onto a conductive substrate and then annealing.

[0067] The annealing conditions include: a temperature of 90℃-110℃, which can be 90℃, 95℃, 100℃, 105℃ or 110℃; and a time of 8-15min, which can be 8min, 9min, 10min, 11min, 12min, 13min, 14min or 15min.

[0068] The solvent for the self-assembled monomolecule solution includes anhydrous ethanol;

[0069] The conditions for spin coating include: a rotation speed of 2000rpm-4000rpm, which can be 2000rpm, 2500rpm, 3000rpm, 3500rpm or 4000rpm; and a time of 20s-40s, which can be 20s, 25s, 30s, 35s or 40s.

[0070] In some embodiments, before fabricating the hole transport layer on the conductive substrate, a pretreatment step is included, which may include: deionized water cleaning, ethanol cleaning, acetone cleaning, isopropanol cleaning, and UV-zone (ultraviolet ozone) treatment.

[0071] In some embodiments, the step of preparing the interface modification layer includes:

[0072] The interface modifier layer was prepared by spin coating, depositing an interface modifier solution onto a hole transport layer, followed by annealing.

[0073] The annealing conditions include: a temperature of 60℃-80℃, which can be 60℃, 65℃, 70℃, 75℃ or 80℃; and a time of 2-10min, which can be 2min, 3min, 4min, 5min, 6min, 7min, 8min, 9min or 10min.

[0074] The solvent for the interface modifier solution includes anhydrous ethanol;

[0075] The conditions for spin coating include: a rotation speed of 2000rpm-4000rpm, which can be 2000rpm, 2500rpm, 3000rpm, 3500rpm or 4000rpm; and a time of 20s-40s, which can be 20s, 25s, 30s, 35s or 40s.

[0076] The modifier solution described in this application is simple to prepare. The interface modification layer is prepared by spin coating and annealing processes, which is fully compatible with the existing perovskite solar cell preparation process. It does not require complex and expensive equipment and is easy to industrialize and promote.

[0077] In some embodiments, the step of preparing the perovskite layer includes:

[0078] The perovskite layer was prepared by spin coating, depositing a solution of perovskite material onto an interface modification layer, followed by annealing.

[0079] The annealing conditions include: a temperature of 140℃-160℃, which can be 140℃, 145℃, 150℃, 155℃ or 160℃; and a time of 10-20min, which can be 10min, 12min, 15min, 16min, 18min, 19min or 20min.

[0080] The solvents in the solution of the perovskite material include N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO).

[0081] The conditions for spin coating include: a rotation speed of 4000rpm-6000rpm, which can be 4000rpm, 4500rpm, 5000rpm, 5500rpm or 6000rpm; and a time of 20s-40s, which can be 20s, 25s, 30s, 35s or 40s.

[0082] The step of depositing a solution of perovskite material onto the interface modification layer also includes:

[0083] The step of adding chlorobenzene during the deposition process.

[0084] In some embodiments, after preparing the perovskite layer, the step of preparing an electron transport layer on the perovskite layer is further included. Specifically, preparing the electron transport layer on the perovskite layer includes:

[0085] The electron transport layer was prepared by vacuum evaporation, in which C60 was deposited onto the perovskite layer.

[0086] The conditions for vacuum evaporation include a velocity of 0.2-0.8 Å / s, which can be 0.2 Å / s, 0.3 Å / s, 0.4 Å / s, 0.5 Å / s, 0.6 Å / s, 0.7 Å / s, or 0.8 Å / s.

[0087] In some embodiments, after the step of fabricating the electron transport layer on the perovskite layer, a step of fabricating a buffer layer on the electron transport layer is further included. Fabricating the buffer layer on the electron transport layer specifically includes:

[0088] The buffer layer was prepared by vacuum evaporation of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline onto the electron transport layer.

[0089] The conditions for vacuum evaporation include a velocity of 0.2-0.8 Å / s, which can be 0.2 Å / s, 0.3 Å / s, 0.4 Å / s, 0.5 Å / s, 0.6 Å / s, 0.7 Å / s, or 0.8 Å / s.

[0090] In some embodiments, after the step of fabricating a buffer layer on the electron transport layer, the step of fabricating an electrode layer on the buffer layer is further included. Specifically, fabricating the electrode layer on the buffer layer includes:

[0091] The electrode layer is prepared by depositing Ag onto the buffer layer using a thermal evaporation deposition method.

[0092] The embodiments of this application will be described in detail below with reference to examples. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of this application. For experimental methods in the following embodiments where specific conditions are not specified, please refer to the guidelines given in this application, or follow experimental manuals or conventional conditions in the art, or follow the conditions recommended by the manufacturer, or refer to experimental methods known in the art.

[0093] Example 1

[0094] Perovskite solar cells (structural schematic diagram as shown) Figure 1 The preparation method of (shown) is as follows:

[0095] 1) Conductive substrate pretreatment:

[0096] Using FTO glass (fluorine-doped tin oxide glass) as the conductive substrate, the FTO was pretreated. The specific steps of the pretreatment were as follows: the FTO was placed in an ultrasonic cleaner and ultrasonically cleaned with deionized water, ethanol, acetone and isopropanol for 10 min each, then dried with a nitrogen gun and treated with UV-zone (ultraviolet ozone) for 20 min to prepare the pretreated conductive substrate.

[0097] 2) Fabrication of the hole transport layer:

[0098] Me-4PACZ ([4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphate) was dissolved in anhydrous ethanol to prepare a Me-4PACZ solution with a concentration of 0.5 mg / mL. The Me-4PACZ solution was deposited on the pretreated conductive substrate by spin coating under the following conditions: 3000 rpm for 30 s. The substrate was then annealed at 100 °C for 10 min to prepare a hole transport layer with a thickness of 1 nm.

[0099] 3) Preparation of the interface modification layer:

[0100] Using 3,5-bis(trifluoromethyl)phenyl isothiocyanate as an interface modifier, the interface modifier was dissolved in anhydrous ethanol to prepare an interface modifier solution with a concentration of 1 mM. The interface modifier solution was deposited on the hole transport layer by spin coating under the following conditions: spin speed of 3000 rpm and time of 30 s. Then, it was annealed at 70 °C for 5 min to prepare an interface modification layer with a thickness of 1 nm.

[0101] 4) Preparation of the perovskite layer:

[0102] 1.6 mol of FAPbI3 perovskite material was dissolved in 1 mL of a mixed solvent of DMF and DMSO with a volume ratio of 4:1, and stirred at 4000 rpm for 2 h to obtain a perovskite precursor solution.

[0103] The perovskite precursor solution was deposited onto the interface modification layer using a spin-coating method. The deposition conditions were: a spin speed of 5000 rpm and a deposition time of 30 s. 15 s before the end of deposition, 300 μL of chlorobenzene was rapidly dropped onto the surface of the perovskite layer to prepare a perovskite wet film. The film was then annealed at 150 °C for 15 min to prepare a perovskite light-absorbing layer with a thickness of 500 nm.

[0104] 5) Fabrication of the electron transport layer:

[0105] An electron transport layer with a thickness of 30 nm was prepared by vacuum evaporation of C60 (fullerene) on the perovskite layer at a rate of 0.5 Å / s.

[0106] 6) Prepare the buffer layer:

[0107] A buffer layer with a thickness of 6 nm was prepared by vacuum evaporation of BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) on the electron transport layer at a rate of 0.5 Å / s.

[0108] 7) Fabrication of metal electrodes:

[0109] The perovskite solar cell is prepared by vacuum evaporation of silver (Ag) onto the hole blocking layer 6 using a thermal evaporation coating method, resulting in a metal electrode (electrode layer) with a thickness of 110 nm.

[0110] Example 2

[0111] The preparation methods of the perovskite solar cells in Example 2 and Example 1 are basically the same, except that 3,5-bis(trifluoromethyl)phenyl isocyanate is used as an interface modifier; the perovskite solar cells are prepared according to the method of Example 1.

[0112] Example 3

[0113] The preparation methods of the perovskite solar cells in Example 3 and Example 1 are basically the same, except that 4-(trifluoromethyl)phenyl isothiocyanate is used as an interface modifier; the perovskite solar cells are prepared according to the method of Example 1.

[0114] Comparative Example 1

[0115] The preparation methods of the perovskite solar cells in Comparative Example 1 and Example 1 are basically the same, except that 1,3-bis(trifluoromethyl)benzene is used as an interface modifier; and the perovskite solar cells are prepared according to the method of Example 1.

[0116] Comparative Example 2

[0117] The preparation method of the perovskite solar cell in Comparative Example 2 is basically the same as that in Example 1, except that: no interface modification layer was prepared; and the perovskite solar cell was prepared according to the method in Example 1.

[0118] Comparative Example 3

[0119] The preparation methods of the perovskite solar cells in Comparative Example 3 and Example 1 are basically the same, except that phenyl isothiocyanate is used as an interface modifier; and the perovskite solar cells are prepared according to the method of Example 1.

[0120] Comparative Example 4

[0121] The preparation methods of the perovskite solar cells in Comparative Example 4 and Example 2 are basically the same, except that phenyl isocyanate is used as an interface modifier; and the perovskite solar cells are prepared according to the method of Example 2.

[0122] Experimental Example 1

[0123] (1) JV tests were conducted using an AM1.5G standard solar simulator, with a starting voltage of 12V, a cutoff voltage of -0.1V, and a scan rate of 100mV / s. Under these test conditions, the short-circuit current density (Jsc), open-circuit voltage (Voc), photoelectric conversion efficiency (Eff), and fill factor (FF) of the perovskite solar cells prepared in Examples 1-3 and Comparative Examples 1-4 were measured. The results are shown in Table 1.

[0124] Table 1 Performance of perovskite solar cells

[0125]

[0126] " / " indicates that it was not added.

[0127] Table 1 shows that, compared with Comparative Examples 1-2, Examples 1-3, using interface modifiers with the structure shown in Formula I—3,5-bis(trifluoromethyl)phenyl isothiocyanate, 3,5-bis(trifluoromethyl)phenyl isothiocyanate, or 4-(trifluoromethyl)phenyl isothiocyanate—increased the Voc of their perovskite solar cells from 1.12V to 1.14V-1.19V, the Eff from 21.80%-21.90% to 22.42%-24.60%, and the FF from 78.5% to 79.3%-82.5%. The significant increase in Voc indicates that interfacial recombination was greatly suppressed, resulting in a better electron blocking effect; the significant increase in FF demonstrates better interfacial contact; and the reduction in interfacial defects and suppression of ion migration greatly alleviated the hysteresis phenomenon in JV scanning.

[0128] Compared with Comparative Example 1, the interface modifiers of Examples 1-2 also have isothiocyanate groups or isocyanate groups, and the Voc of their perovskite solar cells increased from 1.12V to 1.14V-1.19V, the Eff increased from 21.90% to 22.79%-24.60%, an increase of 4%-12%, and the FF increased from 78.5% to 80.3%-82.5%, an increase of 2%-5%.

[0129] Compared with Comparative Example 2, Examples 1-3 used interface modifiers, and their perovskite solar cells increased Voc from 1.12V to 1.14V-1.19V, Eff from 21.80% to 22.42%-24.60%, an increase of 5%-13%, and FF from 78.5% to 79.3%-82.5%.

[0130] Comparing Comparative Examples 1-3 and Example 1, it can be seen that, compared with the use of interface modifiers with only two trifluoromethyl groups or isothiocyanate groups, the interface modifier 3,5-bis(trifluoromethyl)phenyl isothiocyanate used in Example 1 has two trifluoromethyl groups and isothiocyanate groups, which can significantly improve the Eff and FF of perovskite solar cells.

[0131] Comparing Comparative Examples 1-2, Comparative Example 4, and Example 2, it can be seen that compared with the use of interface modifiers with only two trifluoromethyl groups or isocyanate groups, the interface modifier 3,5-bis(trifluoromethyl)phenyl isothiocyanate used in Example 2 has two trifluoromethyl groups and isocyanate groups, which can significantly improve the Eff and FF of perovskite solar cells.

[0132] Comparing Examples 1 and 2, it can be seen that, compared with Example 2 which uses an interface modifier containing isocyanate groups, Example 1 uses an interface modifier containing isothiocyanate groups. As a result, the Voc of the perovskite solar cell increased from 1.14V to 1.19V, the Eff increased from 22.79% to 24.60%, an increase of 8%, and the FF increased from 80.3% to 82.5%.

[0133] Comparing Examples 1 and 3, it can be seen that, compared to Example 3 which only used an interface modifier containing one trifluoromethyl group, Example 1 used an interface modifier containing two trifluoromethyl groups and having a symmetrical structure. The Voc of its perovskite solar cell increased from 1.14V to 1.19V, the Eff increased from 22.42% to 24.60%, an increase of 10%, and the FF increased from 79.3% to 82.5%. This indicates that 3,5-bis(trifluoromethyl)phenyl isothiocyanate can effectively optimize the interface energy levels, suppress non-radiative recombination, and promote perovskite film formation, thereby improving the Voc and FF of the device and significantly enhancing the PCE.

[0134] (2) The perovskite solar cells prepared in Comparative Example 2 and Example 1 were stored in a constant temperature and humidity chamber at 30°C and 75% RH for 14 days to conduct a storage stability experiment. The photoelectric conversion efficiency (Eff) of the perovskite solar cells was measured at 0, 2, 4, 7 and 14 days of storage. The results are as follows: Figure 2 As shown.

[0135] Figure 2 The results show that, compared with Comparative Example 2, the perovskite solar cell in Example 1, which incorporates an interface modification layer, can significantly improve the stability of the perovskite solar cell.

[0136] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0137] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A perovskite solar cell, characterized by, The perovskite solar cell comprises a conductive substrate, a hole transport layer, an interface modification layer and a perovskite layer which are sequentially stacked. The conductive substrate comprises a metal oxide. The hole transport layer comprises a self-assembled monomer. The perovskite layer comprises a perovskite material; the perovskite material comprises Pb 2+ ; The interface modification layer comprises an interface modifier, and the interface modifier has a structure shown in formula I: Formula I; A comprises an isothiocyanate group or an isocyanate group. n represents the number of CF3, and n is 1-2.

2. The perovskite solar cell according to claim 1, characterized in that, The interface modifier comprises at least one of the structures shown in the following formulae: 。 3. The perovskite solar cell according to claim 1 or 2, characterized in that, The self-assembled monomer comprises at least one of a silane-based self-assembled monomer, a phosphoric acid-based self-assembled monomer and a thiol-based self-assembled monomer.

4. The perovskite solar cell according to claim 3, characterized in that, The phosphoric acid-based self-assembling monolayer includes [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid, [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid, [3-(3,6-dimethoxy-9H-carbazol-9-yl)propyl]phosphonic acid, [6-(3,6-dimethoxy-9H-carbazol-9-yl)hexyl]phosphonic acid, [2-(3,6-dimethyl-9H-carbazol-9-yl)ethyl]phosphonic acid, [3-(3,6-dimethyl-9H-carbazol-9-yl)propyl]phosphonic acid, [6-(3,6-dimethyl-9H-carbazol-9-yl)hexyl]phosphonic acid, [1-(3,6-dimethyl-9H-carbazol-9-yl)methyl]phosphonic acid, [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid, [8-(3,6-dimethyl-9H-carbazol-9-yl)octyl]phosphonic acid, [1-(9H-carbazol-9-yl)methyl]phosphonic acid, [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, [3-(9H-carbazol-9-yl)propyl]phosphonic acid, [4-(9H-carbazol-9-yl)butyl]phosphonic acid, [6-(9H-carbazol-9-yl)hexyl]phosphonic acid, [8-(9H-carbazol-9-yl)octyl]phosphonic acid, [(4-(N,N-di(4-methoxyphenylamino)phenyl)propyl]phosphonic acid, 2,3,4,5,6-pentafluorobenzylphosphonic acid, [2-(9H-9 ， -phenyl-3,3 ， -dicumylcarbazol-9-yl)ethyl]phosphonic acid, [4-(9H-9 ， -phenyl-3,3 ， - at least one of [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino)phenyl]phosphonic acid, [4-(diphenylamino)phenyl]phosphinic acid, [4-(diphenylamino 5.The perovskite solar cell of claim 1 or 2, characterized in that, The perovskite material includes ABX3; wherein A includes at least one of FA + , Cs + , and MA + ; B includes Pb 2+ , or Pb 2+ and Sn 2+ ; and X includes at least one of I - , Br - , and Cl - .

6. The perovskite solar cell according to claim 5, characterized in that, The perovskite material comprises FAPbI3.

7. The perovskite solar cell according to claim 1 or 2, characterized in that, The thickness of the interface modification layer is 1-5 nm. 8.The perovskite solar cell of claim 1 or 2, characterized in that, The perovskite solar cell further comprises an electron transport layer, a buffer layer and an electrode layer which are sequentially stacked; and the electron transport layer is arranged between the perovskite layer and the buffer layer.

9. The method of producing a perovskite solar cell according to any one of claims 1 to 8, wherein The method comprises the following steps: The hole transport layer, the interface modification layer and the perovskite layer are sequentially prepared on the conductive substrate. 10.The method of claim 9, wherein the perovskite solar cell is prepared by the steps of: The step of sequentially preparing the hole transport layer, the interface modification layer and the perovskite layer on the conductive substrate comprises: The hole transport layer, the interface modification layer and the perovskite layer are sequentially prepared on the conductive substrate by using a wet deposition method.

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