CN118019419A - Perovskite solar cell and preparation method thereof and photovoltaic device - Google Patents

Abstract

The present invention discloses a perovskite solar cell and a preparation method thereof and a photovoltaic device. The method comprises the following steps: preparing a perovskite film layer; and introducing a passivator into the bulk phase or the surface interface of the perovskite film layer by an antisolvent method, a bulk phase doping method or a surface passivation method to form a passivation layer, wherein the perovskite film layer is subjected to an annealing treatment once when the passivation layer is prepared by the antisolvent method or the bulk phase doping method, and the perovskite film layer is subjected to an annealing treatment twice when the passivation layer is prepared by the surface passivation method, and the passivator comprises one or more of p-fluorobenzonitrile, p-chlorobenzonitrile, p-iodobenzonitrile and p-bromobenzonitrile. The present invention introduces a passivator into the bulk phase or the interface of the perovskite film through different preparation processes, effectively improves the crystallization quality of the perovskite film, reduces the recombination of carriers at the grain boundary, and passivates the defects of the bulk phase or the interface of the perovskite film, thereby effectively improving the efficiency and stability of the photovoltaic device.

Description

Perovskite solar cell and preparation method thereof and photovoltaic device

Technical Field

The present application relates to the field of photovoltaic technology, and in particular to a perovskite solar cell and a preparation method thereof, as well as a photovoltaic device.

Background technique

In the photovoltaic field, perovskite solar cells (PSCs) have attracted much attention among the third-generation solar cells due to their excellent photoelectric performance, high photoelectric conversion efficiency, low cost and simple preparation process. In recent years, organic-inorganic hybrid perovskite solar cells have developed rapidly, and their photoelectric conversion efficiency (PCE) has increased from 3.8% to 26.1%. However, there is still a certain gap between the actual use scenario and its theoretical limit efficiency. At the same time, the perovskite light-absorbing layer has poor stability under the long-term effects of moisture, oxygen, light and heat, which leads to a reduction in the service life of perovskite solar cells and seriously affects the commercial application of batteries. An important reason affecting the efficiency and stability of the battery is that the perovskite film prepared by the solution method is polycrystalline, and there are a large number of defects on its surface, grain boundaries and bulk phase. These defects can cause serious recombination of photogenerated carriers and cause ion migration and water oxygen infiltration. The passivation strategy for perovskite defects mainly focuses on eliminating deep energy level defects caused by uncoordinated metal cations or halogen anions, as well as shallow energy level defects formed by iodine ion vacancies/interstices by introducing passivator molecules to form coordination bonds with ions in perovskites.

There are many kinds of passivators currently used for defect passivation of perovskite films, mainly including alkaline halides, organic molecules, organic halide salts, polymers, metal halides and low-dimensional perovskites. Among them, multifunctional organic small molecules are more likely to combine with and interact with perovskites due to their small size, high solubility and good permeability. The current passivators for defect passivation of perovskite films still have many problems in the perovskite defect passivation strategy.

Summary of the invention

Based on this, it is necessary to provide a method for preparing a perovskite solar cell. The method for preparing a perovskite solar cell of the present invention modifies the perovskite film by a solution method, introduces a passivator into the perovskite film, effectively passivates the defects of the perovskite film, reduces the defect density of the perovskite light absorption layer, and reduces the non-radiative recombination of the perovskite film, thereby improving the stability of the device while improving the battery efficiency.

An embodiment of the present application provides a method for preparing a perovskite solar cell.

A method for preparing a perovskite solar cell comprises the following steps:

preparing a perovskite thin film layer;

And a passivation layer is formed by introducing a passivating agent into the bulk phase or the surface interface of the perovskite film layer by adopting an antisolvent method, a bulk doping method or a surface passivation method, wherein when the passivation layer is prepared by the antisolvent method or the bulk doping method, the perovskite film layer is subjected to an annealing treatment once, and when the passivation layer is prepared by the surface passivation method, the perovskite film layer is subjected to an annealing treatment twice, and the passivating agent includes one or more of p-fluorobenzonitrile, p-chlorobenzonitrile, p-iodobenzonitrile and p-bromobenzonitrile.

In some embodiments, the structural formula of the perovskite thin film layer is ABX ₃ , wherein A is one or more of methylamine, formamidine, acetamidine, cesium or rubidium, B is one or more of lead, tin, copper and germanium, and X is one or more of F ^- , I ^- , Br ^- , Cl ^- , BF ₄ ^- , PF ₆ ^- and SCN ^- .

In some embodiments, when the passivating agent is introduced into the bulk phase or the surface interface of the perovskite thin film layer by the anti-solvent method, the following steps are specifically included:

The passivator is dissolved in an anti-solvent, and the anti-solvent containing the passivator is directly introduced into the perovskite film layer during spin coating of the perovskite precursor solution. After a single annealing treatment, a perovskite film layer containing the passivator is formed. The concentration range of the passivator is 0.1 mg/mL to 20 mg/mL, the temperature range of the single annealing treatment is 60°C to 180°C, and the time is 1 min to 80 min.

In some embodiments, when the passivating agent is introduced into the bulk phase or the surface interface of the perovskite thin film layer by the bulk doping method, the steps are specifically as follows:

The passivator is dissolved in a perovskite precursor solvent, wherein the concentration range of the passivator is 0.1 mg/mL to 20 mg/mL, the perovskite precursor solvent is spin-coated and subjected to an annealing treatment to form the perovskite film layer and the passivation layer, wherein the temperature range of the annealing treatment is 60° C. to 180° C., and the time is 1 min to 80 min.

In some embodiments, when the passivation agent is introduced into the bulk or surface interface of the perovskite thin film layer by a surface passivation method, the following steps are specifically included:

Spin coating a perovskite precursor solvent and performing a primary annealing treatment to form the perovskite thin film layer, wherein the temperature range of the primary annealing treatment is 60° C. to 180° C., and the time is 1 min to 80 min;

A passivator is dissolved in an anti-solvent, wherein the concentration range of the passivator is 0.1 mg/mL to 20 mg/mL, and the anti-solvent is coated on the upper surface of the crystallized perovskite film. After a secondary annealing treatment, the passivator is introduced into the bulk phase or the surface interface of the perovskite film to form the passivation layer. The temperature range of the secondary annealing treatment is 50° C. to 180° C., and the time is 1 min to 30 min.

In some embodiments, the anti-solvent includes one or more of chlorobenzene, ethyl acetate, anisole, ethyl ether, ethanol and isopropanol.

An embodiment of the present application also provides a perovskite solar cell.

A perovskite solar cell is prepared by the above-mentioned preparation method.

In some of the embodiments, the perovskite solar cell includes a transparent conductive substrate, a first functional layer, a perovskite thin film layer, a passivation layer, a second functional layer, a barrier layer and a metal electrode which are stacked in sequence.

In some embodiments, the first functional layer and the second functional layer are a hole transport layer and an electron transport layer, respectively.

In some embodiments, the transparent conductive substrate is a flexible substrate or a rigid substrate, wherein the rigid substrate comprises ITO transparent conductive glass or FTO transparent conductive glass;

And/or, a modification layer and/or a buffer layer is provided between the barrier layer and the metal electrode.

An embodiment of the present application also provides a photovoltaic device.

A photovoltaic device comprises a packaging structure and the perovskite solar cell prepared by the above-mentioned preparation method, wherein the packaging structure is used to encapsulate the perovskite solar cell.

The preparation method of the above-mentioned perovskite solar cell adopts any one of the anti-solvent method, bulk doping method or surface passivation method to introduce the passivator into the bulk phase or surface interface of the perovskite film, and after one or two annealing treatments, the crystallization quality of the perovskite film can be effectively improved, the uncoordinated Pb ²⁺ and iodine vacancy defects in the perovskite film can be passivated, and the non-radiative recombination of photogenerated carriers can be reduced. The passivator used in the present application can exhibit the characteristics of Lewis base, and the nitrile group (-CN) therein can effectively passivate the uncoordinated Pb ²⁺ and iodine vacancy defects in the perovskite film. At the same time, the halogen ions in the passivator, such as F- ^/ CL- ^{/ I-} / ^Br-, can also improve the crystallization quality of the film and compensate for the halogen ion deficiency caused by the perovskite during the annealing process, so that its voltage, current, fill factor and efficiency are all improved.

The present application introduces a passivator into the bulk phase or interface of the perovskite film through different preparation processes, effectively improves the crystallization quality of the perovskite film, reduces the recombination of carriers at the grain boundary, and passivates the defects in the bulk phase or interface of the perovskite film, thereby effectively improving the efficiency and stability of the photovoltaic device. The specific method is: the passivator is dissolved in a solvent, and the passivator is applied to the upper surface of the perovskite film by a solution method, thereby effectively passivating the defects in the bulk phase/interface of the perovskite film, and inducing secondary growth of small-sized grains during the secondary annealing process, reducing the grain boundaries of the perovskite film, improving the crystallization quality of the perovskite film, and effectively improving the photoelectric performance of the photovoltaic device. The passivator material is dissolved in the antisolvent by the antisolvent method, and the passivating material is introduced into the perovskite film during the dripping of the antisolvent, thereby effectively passivating the defects in the bulk phase/interface of the perovskite film, and effectively improving the efficiency of the device. The passivator material is dissolved in the perovskite precursor solution, and the perovskite film is prepared by a solution method, thereby effectively passivating the defects in the bulk/interface of the perovskite film and effectively improving the efficiency of the photovoltaic device.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings. In the following description, the same reference numerals represent the same parts.

FIG1 is a schematic diagram of a perovskite solar cell according to an embodiment of the present invention.

Description of Reference Numerals

10. Perovskite solar cell; 100. Transparent conductive substrate; 200. Hole transport layer; 300. Perovskite thin film layer; 400. Passivation layer; 500. Electron transport layer; 600. Hole blocking layer; 700. Metal electrode.

Detailed ways

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

In the description of the present invention, "several" means more than one, "many" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

In this article, unless otherwise stated, each reaction step may be carried out in the order described herein or may not be carried out in the order described herein. For example, other steps may be included between each reaction step, and the order of the reaction steps may also be appropriately swapped. This can be determined by the technician based on common knowledge and experience. Preferably, the reaction method herein is carried out sequentially.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and/or" used herein includes any and all combinations of one or more of the related listed items.

The present application provides a perovskite solar cell 10 and a method for preparing the same, so as to solve the problem of low efficiency and short service life of the perovskite solar cell caused by defects in the perovskite film during the preparation process of the perovskite solar cell in the conventional technology. The preparation method of the perovskite solar cell 10 will be described below in conjunction with the accompanying drawings.

The method for preparing the perovskite solar cell 10 provided in the embodiment of the present application is illustrative, please refer to FIG1, which is a schematic diagram of the structure of the perovskite solar cell 10 provided in the embodiment of the present application. The method for preparing the perovskite solar cell 10 of the present application can reduce the defects of the perovskite bulk phase and the surface interface, further reduce the non-radiative recombination of carriers in the perovskite cell, and improve the photoelectric performance and stability of the solar cell.

In order to more clearly illustrate the structure of the perovskite solar cell 10 , the perovskite solar cell 10 will be introduced below with reference to the accompanying drawings.

For example, please refer to FIG. 1 , which is a schematic diagram of the structure of a perovskite solar cell 10 provided in an embodiment of the present application.

A method for preparing a perovskite solar cell 10 comprises the following steps:

Prepare a perovskite film layer; and introduce a passivating agent into the bulk phase or the surface interface of the perovskite film layer by an anti-solvent method, a bulk doping method or a surface passivation method to form a passivation layer, wherein when the passivation layer is prepared by the anti-solvent method or the bulk doping method, the perovskite film layer is subjected to an annealing treatment once, and when the passivation layer is prepared by the surface passivation method, the perovskite film layer is subjected to an annealing treatment twice, and the passivating agent includes one or more of p-fluorobenzonitrile, p-chlorobenzonitrile, p-iodobenzonitrile and p-bromobenzonitrile.

The preparation method of the above-mentioned perovskite solar cell 10 adopts any one of the anti-solvent method, bulk doping method or surface passivation method to introduce the passivator into the bulk phase or surface interface of the perovskite film. After one or two annealing treatments, the crystallization quality of the perovskite film can be effectively improved, the uncoordinated Pb ²⁺ and iodine vacancy defects in the perovskite film can be passivated, and the non-radiative recombination of photogenerated carriers can be reduced. The passivator used in the present application can exhibit the characteristics of Lewis base, and the nitrile group (-CN) therein can effectively passivate the uncoordinated Pb ²⁺ and iodine vacancy defects in the perovskite film. At the same time, the halogen ions in the passivator, such as F- ^{/ CL-} / ^I- / ^Br-, can also improve the crystallization quality of the film and compensate for the halogen ion deficiency caused by the perovskite during the annealing process, so that its voltage, current, fill factor and efficiency are all improved.

In some embodiments, the structural formula of the perovskite thin film layer is ABX ₃ , wherein A is one or more of methylamine, formamidine, acetamidine, cesium or rubidium, B is one or more of lead, tin, copper and germanium, and X is one or more of F ^- , I ^- , Br ^- , Cl ^- , BF ₄ ^- , PF ₆ ^- and SCN ^- .

In some embodiments, when the passivating agent is introduced into the bulk phase or the surface interface of the perovskite thin film layer by the anti-solvent method, the following steps are specifically included:

The passivator is dissolved in an anti-solvent, and the anti-solvent containing the passivator is directly introduced into the perovskite film layer during the spin coating process of the perovskite precursor solution, and a perovskite film layer containing the passivator is formed after a single annealing treatment, wherein the concentration range of the passivator is 0.1 mg/mL to 20 mg/mL, the temperature range of the single annealing treatment is 60° C. to 180° C., and the time is 1 min to 80 min. The passivator forms a passivation layer.

In some embodiments, when the passivating agent is introduced into the bulk phase or the surface interface of the perovskite thin film layer by the bulk doping method, the steps are specifically as follows:

The passivator is dissolved in a perovskite precursor solvent, wherein the concentration range of the passivator is 0.1 mg/mL to 20 mg/mL, the perovskite precursor solvent is spin-coated and subjected to an annealing treatment to form a perovskite film layer and a passivation layer, wherein the temperature range of the annealing treatment is 60° C. to 180° C., and the time is 1 min to 80 min.

In some embodiments, when the passivation agent is introduced into the bulk or surface interface of the perovskite thin film layer by a surface passivation method, the following steps are specifically included:

Spin coating a perovskite precursor solvent and performing a primary annealing treatment to form a perovskite thin film layer, wherein the temperature range of the primary annealing treatment is 60° C. to 180° C., and the time is 1 min to 80 min;

The passivator is dissolved in an anti-solvent, the concentration range of the passivator is 0.1 mg/mL to 20 mg/mL, the anti-solvent is coated on the surface of the crystallized perovskite film, and the passivator is introduced into the bulk phase or surface interface of the perovskite film after a secondary annealing treatment to form a passivation layer. The temperature range of the secondary annealing treatment is 50°C to 180°C, and the time is 1min to 30min.

In some embodiments, the anti-solvent includes one or more of chlorobenzene, ethyl acetate, anisole, ethyl ether, ethanol and isopropanol.

An embodiment of the present application further provides a perovskite solar cell 10 .

A perovskite solar cell 10 is prepared by the above-mentioned preparation method.

In some of the embodiments, the perovskite solar cell 10 includes a transparent conductive substrate 100, a first functional layer, a perovskite thin film layer 300, a passivation layer 400, a second functional layer, a barrier layer and a metal electrode 700 which are stacked in sequence.

In some embodiments, the first functional layer and the second functional layer are the hole transport layer 200 and the electron transport layer 500, respectively.

In some embodiments, the metal electrode 700 is a transparent counter electrode.

In some embodiments, the first functional layer is the electron transport layer 500 or the hole transport layer 200 , and correspondingly, the second functional layer is the hole transport layer 200 or the electron transport layer 500 .

For example, in one embodiment, the perovskite solar cell 10 includes a transparent conductive substrate 100, a hole transport layer 200, a perovskite thin film layer 300, a passivation layer 400, an electron transport layer 500, a hole blocking layer 600 and a metal electrode 700 which are stacked in sequence.

In some embodiments, the transparent conductive substrate 100 is a flexible substrate or a rigid substrate, wherein the rigid substrate includes ITO (indium tin oxide) transparent conductive glass or FTO (fluoride-doped tin oxide) transparent conductive glass.

In some of the embodiments, a modification layer and/or a buffer layer is further provided between the barrier layer and the metal electrode 700 .

In some embodiments, the material of the electron transport layer 500 (ETL) includes one or more of PCBM ([6,6]-phenyl-C71-butyric acid isomethyl ester), SnO ₂ , ZnO ₂ , Al ₂ O ₃ , C ₆₀ , and ICBA (indene-C60 bis-adduct).

In some of the embodiments, the preparation material of the hole transport layer 200 (HTL) includes one or more of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid and its derivatives, [2-(9H-carbazole-9-yl)butyl]phosphonic acid and its derivatives, 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene, polyethylene terephthalate, 3-hexylthiophene polymer, PEDOT:PSS (poly 3,4-ethylenedioxythiophene:polystyrene sulfonate), NiO _x and CuSCN.

In some embodiments, the perovskite solar cell 10 may be a regular perovskite solar cell or an inverted perovskite solar cell.

An embodiment of the present application also provides a photovoltaic device.

A photovoltaic device comprises a packaging structure and a perovskite solar cell 10 prepared by the above-mentioned preparation method, wherein the packaging structure is used to package the perovskite solar cell 10.

Example 1

This embodiment provides a perovskite solar cell 10 .

The perovskite solar cell 10 of this embodiment is prepared by the following preparation method.

A method for preparing a perovskite solar cell 10 comprises the following steps:

(1) FAI, _PbI2 , MACl, MAI, and CsI powders were mixed in a molar ratio of 140:173:15:40:8, and 1 mL of DMF (N,N-dimethylformamide) and DMSO (wherein the volume ratio of DMF to DMSO was 4:1) was added to dissolve them to obtain FA _0.85 MA _0.1 Cs _0.05 PbI ₃ perovskite precursor solution; the hole transport layer 200 material 2PACZ ([2-(9H-carbazole-9-yl)ethyl]phosphonic acid) was dissolved in IPA (isopropanol) solution; the passivator material p-fluorobenzonitrile was added to the anti-solvent solution (CB) at a concentration of 5 mg/mL.

(2) The ITO transparent conductive glass is cleaned and blown dry with nitrogen to form the transparent conductive substrate 100 .

(3) The hole transport layer 200 material 2PACZ is prepared on the ITO transparent conductive glass by a spin coating method to obtain the hole transport layer 200, and an annealing treatment is performed to remove the solvent. The temperature of the annealing treatment is 100°C and the time is 10 minutes.

(4) The perovskite precursor solution is prepared on the hole transport layer 200 by a spin coating method to obtain a perovskite thin film layer. An anti-solvent is added during the spin coating process. During the spin coating and annealing treatment (150°C, 30 min), the passivator molecules in the anti-solvent enter the bulk phase and surface interface of the perovskite thin film layer to form a perovskite thin film layer 300 containing a passivator and a passivation layer 400 formed by the passivator, thereby effectively passivating various defects in the perovskite thin film.

(5) On the perovskite thin film layer prepared in the above step (4), a 30 nm thick C ₆₀ is sequentially evaporated as an electron transport layer 500, a 6 nm thick BCP (2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline) is evaporated as a hole blocking layer 600, and a 150 nm thick Au electrode is evaporated as a metal electrode 700 by vacuum evaporation.

Example 2

This embodiment provides a perovskite solar cell 10 .

The perovskite solar cell 10 of this embodiment is prepared by the following preparation method.

A method for preparing a perovskite solar cell 10 comprises the following steps:

(1) FAI, _PbI2 , MACl, MAI, and CsI powders were mixed in a molar ratio of 140:173:15:40:8, and 1.3 mL of DMF and NMP (dimethylpyrrolidone) were added for dissolution (wherein the volume ratio of DMF and NMP was 1000:300) to obtain a FA _0.85 MA _0.1 Cs _0.05 PbI ₃ perovskite precursor solution; the hole transport layer 200 material 2PACZ was dissolved in the IPA solution.

(2) Add the passivating agent p-bromobenzonitrile to the perovskite precursor solution, and the concentration of p-bromobenzonitrile is 4 mg/mL.

(3) Clean the ITO transparent conductive glass and blow dry it with nitrogen.

(4) The hole transport layer 200 material 2PACZ is prepared on the ITO transparent conductive glass by a slit coating method to obtain the hole transport layer 200, and an annealing treatment is performed to remove the solvent. The temperature of the annealing treatment is 100° C. and the time is 10 min.

(5) The perovskite precursor solution is prepared on the hole transport layer 200 by a slit coating method to obtain a perovskite thin film layer. During the annealing treatment (150°C, 30 min), the passivator molecules enter the bulk and surface interface of the perovskite thin film layer to form a perovskite thin film layer 300 containing the passivator, thereby effectively passivating various defects in the perovskite thin film.

(6) On the perovskite thin film layer prepared in the above step (5), a 30 nm thick C ₆₀ is sequentially evaporated as an electron transport layer 500, a 6 nm thick BCP (2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline) is evaporated as a hole blocking layer 600, and a 150 nm thick Au electrode is evaporated as a metal electrode 700 by vacuum evaporation.

Example 3

This embodiment provides a perovskite solar cell 10 .

The perovskite solar cell 10 of this embodiment is prepared by the following preparation method.

A method for preparing a perovskite solar cell 10 comprises the following steps:

FAI, _PbI2 , MACl, MAI, and CsI powders were mixed in a molar ratio of 140:173:15:40:8, and 1.3 mL of DMF and NMP (dimethylpyrrolidone) were added for dissolution (wherein the volume ratio of DMF and NMP was 1000:300) to obtain FA _0.85 MA _0.1 Cs _0.05 PbI ₃ perovskite precursor solution; the hole transport layer 200 material 2PACZ was dissolved in the IPA solution; the passivator material p-bromobenzonitrile was added to the anti-solvent solution (CB), and the p-bromobenzonitrile concentration was 6 mg/mL.

(2) Clean the ITO transparent conductive glass and blow dry it with nitrogen.

(3) The hole transport layer 200 material 2PACZ is prepared on the ITO transparent conductive glass by a doctor blade method to obtain the hole transport layer 200, and then annealed to remove the solvent.

(4) The perovskite precursor solution is applied on the hole transport layer 200 by a scraping method, and a crystallized perovskite film layer is obtained after a first annealing treatment. The temperature of the first annealing treatment is 100°C and the time is 40 minutes. Then the passivator solution is spin-coated on the surface of the crystallized perovskite film layer again, and then a second annealing treatment is performed to allow the passivator molecules to enter the bulk and surface interface of the perovskite film, forming a perovskite film layer 300 containing a passivator and a passivation layer 400 formed by the passivator, thereby effectively passivating various defects in the perovskite film. The temperature of the second annealing treatment is 100°C and the time is 15 minutes.

(5) On the passivation layer prepared in the above (4), PCBM ([6,6]-phenyl-C71-butyric acid isomethyl ester) material is successively coated by a scraping method as an electron transport layer 500, and BCP material is scraped to form a hole blocking layer 600, and finally a 150 nm thick Au electrode is evaporated as a metal electrode 700.

Example 4

This embodiment provides a perovskite solar cell 10 .

The preparation method of the perovskite solar cell 10 of this embodiment is basically the same as that of embodiment 1, except that the temperature of the first annealing treatment in step (4) of this embodiment is 120° C. and the time is 40 min.

Example 5

This embodiment provides a perovskite solar cell 10 .

The preparation method of the perovskite solar cell 10 of this embodiment is basically the same as that of embodiment 2, except that: the temperature of the first annealing treatment in step (5) of this embodiment is 120° C. and the time is 50 min.

Example 6

This embodiment provides a perovskite solar cell 10 .

The preparation method of the perovskite solar cell 10 of this embodiment is basically the same as that of embodiment 3, except that: in step (4) of this embodiment, the temperature of the first annealing treatment is 150° C. and the time is 20 min, and the temperature of the second annealing treatment is 80° C. and the time is 30 min.

Comparative Example 1

This comparative example provides a perovskite solar cell.

The preparation method of the perovskite solar cell in this comparative example is basically the same as that in Example 1, except that: the anti-solvent solution (CB) does not contain p-fluorobenzonitrile.

Comparative Example 2

This comparative example provides a perovskite solar cell.

The preparation method of the perovskite solar cell in this comparative example is basically the same as that in Example 2, except that: the perovskite precursor solution does not contain p-bromobenzonitrile.

Comparative Example 3

This comparative example provides a perovskite solar cell.

The preparation method of the perovskite solar cell in this comparative example is basically the same as that in Example 3, except that p-bromobenzonitrile is not used to passivate the surface of the perovskite film.

Comparative Example 4

This comparative example provides a perovskite solar cell.

The preparation method of the perovskite solar cell in this comparative example is basically the same as that in Example 2, except that the temperature of the first annealing treatment in step (4) of this example is 60° C. and the time is 30 min.

Comparative Example 5

This comparative example provides a perovskite solar cell.

The preparation method of the perovskite solar cell in this comparative example is basically the same as that in Example 3, except that: in step (4) of this example, the temperature of the first annealing treatment is 180° C. and the time is 20 min, and the temperature of the second annealing treatment is 150° C. and the time is 10 min.

Comparative Example 6

This comparative example provides a perovskite solar cell.

The preparation method of the perovskite solar cell in this comparative example is basically the same as that in Example 3, except that: in step (4) of this example, the temperature of the first annealing treatment is 80° C. and the time is 60 min, and the temperature of the second annealing treatment is 60° C. and the time is 30 min.

The performance of the perovskite solar cells 10 prepared in Examples 1 to 6 and Comparative Examples 1 to 6 was tested, and the test results are shown in Table 1.

Table 1

In summary, the present application introduces a passivator into the bulk phase or interface of the perovskite film through different preparation processes, effectively improves the crystallization quality of the perovskite film, reduces the recombination of carriers at the grain boundaries, and passivates the defects of the bulk phase or interface of the perovskite film, thereby effectively improving the efficiency and stability of the photovoltaic device. The specific method is: the passivator is dissolved in an anti-solvent, and the passivator is applied to the upper surface of the perovskite film by a surface passivation method, thereby effectively passivating the defects of the bulk phase/interface of the perovskite film, and inducing secondary growth of small-sized grains during the secondary annealing process, reducing the grain boundaries of the perovskite film, improving the crystallization quality of the perovskite film, and effectively improving the photoelectric performance of the photovoltaic device. The passivator material is dissolved in the anti-solvent by the anti-solvent method, and the passivating material is introduced into the perovskite film during the dripping of the anti-solvent, thereby effectively passivating the defects of the bulk phase/interface of the perovskite film, and effectively improving the efficiency of the device. The passivator material is dissolved in the perovskite precursor solution, and the perovskite film is prepared by a solution method, thereby effectively passivating the defects in the bulk/interface of the perovskite film and effectively improving the efficiency of the photovoltaic device.

In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims (10)

1. The preparation method of the perovskite solar cell is characterized by comprising the following steps of:

preparing a perovskite thin film layer;

And introducing a passivating agent into the bulk phase or surface interface of the perovskite film layer by adopting an anti-solvent method, a bulk phase doping method or a surface passivation method to form a passivation layer, wherein the perovskite film layer is subjected to primary annealing treatment when the passivation layer is prepared by adopting the anti-solvent method and the bulk phase doping method, and the perovskite film layer is subjected to secondary annealing treatment when the passivation layer is prepared by adopting the surface passivation method, and the passivating agent comprises one or more of p-fluorobenzonitrile, p-chlorobenzonitrile, p-iodobenzonitrile and p-bromobenzonitrile.

2. The method for preparing a perovskite solar cell according to claim 1, wherein the structural formula of the perovskite thin film layer is ABX ₃, wherein a is one or more of methylamine, formamidine, acetamidine, cesium or rubidium, B is one or more of lead, tin, copper and germanium, and X is one or more of F ^-、I^-、Br^-、Cl^-、BF₄ ^-、PF₆ ^- and SCN ^-.

3. The method for preparing the perovskite solar cell according to claim 1, wherein when the passivating agent is introduced into the perovskite thin film layer at the bulk phase or the surface interface by adopting an anti-solvent method, the method specifically comprises the following steps:

Dissolving a passivating agent in an antisolvent, directly introducing the antisolvent containing the passivating agent into a perovskite film layer in the process of spin coating of a perovskite precursor solution, and performing primary annealing treatment to form the perovskite film layer containing the passivating agent, wherein the concentration range of the passivating agent is 0.1 mg/mL-20 mg/mL, and the temperature range during primary annealing treatment is 60-180 ℃ and the time is 1-80 min.

4. The method for manufacturing a perovskite solar cell according to claim 1, wherein when a passivating agent is introduced into a perovskite thin film layer at a bulk phase or a surface interface by a bulk phase doping method, the method specifically comprises the following steps:

dissolving a passivating agent in a perovskite precursor solvent, wherein the concentration range of the passivating agent is 0.1 mg/mL-20 mg/mL, spin-coating the perovskite precursor solvent, and forming the perovskite film layer and the passivating layer through primary annealing treatment, wherein the temperature range during primary annealing treatment is 60-180 ℃ and the time is 1-80 min.

5. The method for preparing the perovskite solar cell according to claim 1, wherein when a surface passivation method is adopted to introduce a passivating agent into a bulk phase or a surface interface of the perovskite thin film layer, the method specifically comprises the following steps:

Spin-coating perovskite precursor solvent and forming the perovskite film layer through primary annealing treatment, wherein the temperature range of the primary annealing treatment is 60-180 ℃ and the time is 1-80 min;

Dissolving a passivating agent in an antisolvent, wherein the concentration range of the passivating agent is 0.1 mg/mL-20 mg/mL, coating the antisolvent on the upper surface of the crystallized perovskite film, introducing the passivating agent into the bulk phase or surface interface of the perovskite film after secondary annealing treatment to form the passivation layer, and the temperature range of the secondary annealing treatment is 50-180 ℃ for 1-30 min.

6. The method for producing a perovskite solar cell according to claim 3 or 5, wherein the antisolvent comprises one or more of chlorobenzene, ethyl acetate, anisole, diethyl ether, ethanol, and isopropanol.

7. A perovskite solar cell, characterized in that it is prepared by the preparation method according to any one of claims 1 to 6.

8. The perovskite solar cell of claim 7, wherein the perovskite solar cell comprises a transparent conductive substrate, a first functional layer, a perovskite thin film layer, a passivation layer, a second functional layer, a barrier layer, and a metal electrode that are sequentially stacked.

9. The perovskite solar cell of claim 8, wherein the first functional layer and the second functional layer are a hole transport layer and an electron transport layer, respectively;

And/or the transparent conductive substrate is a flexible substrate or a rigid substrate, wherein the rigid substrate comprises ITO transparent conductive glass or FTO transparent conductive glass;

And/or a decorative layer and/or a buffer layer are/is arranged between the barrier layer and the metal electrode.

10. A photovoltaic device comprising a packaging structure and the perovskite solar cell prepared by the preparation method of any one of claims 1 to 6 or the perovskite solar cell of any one of claims 7 to 9, wherein the packaging structure is used for packaging the perovskite solar cell.