Perovskite solar cell and preparation method thereof, solar cell module and power utilization device

Abstract

The invention relates to the field of solar cells, and particularly discloses a perovskite solar cell, a preparation method thereof and a power utilization device. The perovskite solar cell comprises a hole transport layer, a perovskite layer, an electron transport layer and a modification layer, wherein the modification layer comprises at least one of a first modification layer and a second modification layer; the hole transport layer, the perovskite layer and the electron transport layer are sequentially stacked; the first modification layer is located between the perovskite layer and the hole transport layer, and the second modification layer is located between the perovskite layer and the electron transport layer; the first modification layer and the second modification layer comprise alkylamine salt. The battery has better stability and energy conversion efficiency.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to perovskite solar cells and preparation methods thereof, solar cell modules and electrical devices. Background Art

[0002] Perovskite solar cells have developed rapidly in the past 10 years. Although perovskite materials have excellent optoelectronic properties, their surface and internal defects will affect the efficiency and stability of the device. These defects will lead to a decrease in charge transfer efficiency, thereby affecting the conversion efficiency of solar cells. At present, passivators are often used to passivate perovskites to improve the efficiency and stability of perovskite solar cells, but the passivation effect of perovskite solar cells is still not ideal and still needs further improvement. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the present invention provides a perovskite solar cell with greatly improved perovskite passivation effect and quality, a preparation method thereof, a solar cell module and an electric device.

[0004] In the first aspect of the present application, a perovskite solar cell is provided. According to an embodiment of the present application, the perovskite solar cell includes a hole transport layer, a perovskite layer, an electron transport layer and a modification layer, wherein the modification layer includes at least one of a first modification layer and a second modification layer; the hole transport layer, the perovskite layer, and the electron transport layer are stacked in sequence; the first modification layer is located between the perovskite layer and the hole transport layer, and the second modification layer is located between the perovskite layer and the electron transport layer; the first modification layer and the second modification layer include alkylamine salts. The cations and anions in the alkylamine salt can be anchored at the grain boundaries of the perovskite, and at the same time, some cations will form a 2D passivation layer on the surface of the perovskite, which enhances the stability of the interface, thereby reducing the non-radiative recombination in the device (i.e., the perovskite solar cell), and the functional layers of the device are more stable, thereby enhancing the stability of the device, achieving the purpose of increasing Voc (i.e., open circuit voltage, which refers to the output voltage of the solar cell when it is open circuit (i.e., no load) under illumination conditions), and improving the device efficiency.

[0005] According to an embodiment of the present application, the alkylamine salt includes at least one of octylamine chloride, phenethylammonium chloride, and octylamine iodide.

[0006] According to an embodiment of the present application, the second modification layer further includes guanidinium halogenate.

[0007] According to an embodiment of the present application, the guanidinium halide salt includes guanidinium chloride.

[0008] According to an embodiment of the present application, in the second modified layer, the mass ratio of the alkylamine salt to the guanidinium halide salt is 1-3:0.5-1.5.

[0009] According to an embodiment of the present application, the modification layer includes the first modification layer and the second modification layer, the first modification layer includes the alkylamine salt, and the second modification layer includes the alkylamine salt and a guanidinium halide salt.

[0010] According to an embodiment of the present application, the thickness of the first modification layer is 1 nm to 20 nm. According to an embodiment of the present application, the thickness of the second modification layer is 1 nm to 20 nm.

[0011] According to an embodiment of the present application, the solar cell further includes a transparent conductive substrate, and the transparent conductive substrate is located on a side of the hole transport layer away from the perovskite layer or a side of the electron transport layer away from the perovskite layer.

[0012] In the second aspect of the present application, a method for preparing the aforementioned perovskite solar cell is provided. According to an embodiment of the present application, the method comprises the following steps: forming a hole transport layer; forming a perovskite layer on one side of the hole transport layer; forming an electron transport layer on the side of the perovskite layer away from the hole transport layer; the method further comprises at least one of the following steps: forming a first modification layer on the surface of the hole transport layer close to the perovskite layer; forming a second modification layer on the surface of the perovskite layer away from the hole transport layer.

[0013] According to an embodiment of the present application, the hole transport layer, the first modified layer, the perovskite layer, the second modified layer and the electron transport layer are formed by a spin coating method.

[0014] According to an embodiment of the present application, the first modification layer is formed by the following steps: preparing a first alkylamine salt solution with a concentration of 0.2 mg / ml to 0.4 mg / ml, and spin coating the solution on the hole transport layer at a rotation speed of 3000 rpm to 5000 rpm for 20s to 40s.

[0015] According to an embodiment of the present application, the second modification layer is formed by any of the following steps: preparing a second alkylamine salt solution with a concentration of 1 mg / ml to 3 mg / ml, spin coating it on the perovskite layer at a rotation speed of 4000 rpm to 6000 rpm for 20s to 30s, and annealing it at 80°C to 120°C for 1min to 5min; preparing a mixed solution with an alkylamine salt concentration of 1 mg / ml to 3 mg / ml and a guanidinium halide concentration of 0.5 mg / ml to 1.5 mg / ml, spin coating it on the perovskite layer at a rotation speed of 4000 rpm to 6000 rpm for 20s to 30s, and annealing it at 80°C to 120°C for 1min to 5min.

[0016] In a third aspect of the present application, a solar cell assembly is provided. According to an embodiment of the present application, the solar cell and assembly include the solar cell described above or the solar cell prepared by the method described above. The solar cell assembly has better stability and higher energy conversion efficiency.

[0017] In a fourth aspect of the present application, an electrical device is provided. According to an embodiment of the present application, the electrical device includes the aforementioned perovskite solar cell, the perovskite solar cell prepared by the aforementioned method, or the aforementioned solar cell module. The electrical device has all the features and advantages of the aforementioned perovskite solar cell, which will not be described one by one here. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of a perovskite solar cell according to an embodiment of the present application.

[0019] Figure 2 It is a schematic structural diagram of a perovskite solar cell according to another embodiment of the present application.

[0020] Figure 3 It is a schematic structural diagram of a perovskite solar cell according to another embodiment of the present application.

[0021] Figure 4 It is a schematic structural diagram of a perovskite solar cell according to another embodiment of the present application.

[0022] Figure 5 It is a schematic structural diagram of a perovskite solar cell according to another embodiment of the present application.

[0023] Figure 6 It is a schematic structural diagram of a perovskite solar cell according to another embodiment of the present application.

[0024] Figure 7 It is a schematic structural diagram of a perovskite solar cell according to another embodiment of the present application.

[0025] Figure 8 It is a schematic structural diagram of a perovskite solar cell according to another embodiment of the present application.

[0026] Fig. 9 It is a JV curve diagram of the perovskite solar cell of Example 3 and Comparative Example 1 of the present application.

[0027] Reference numerals:

[0028] 1: Transparent conductive substrate 2: Hole transport layer 3: Perovskite layer 4: Electron transport layer 5: Metal electrode 61: First modified layer 62: Second modified layer DETAILED DESCRIPTION

[0029] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0030] In a first aspect of the present application, a perovskite solar cell is provided. According to an embodiment of the present application, referring to Figure 1 to Figure 3 The perovskite solar cell comprises a hole transport layer 2, a perovskite layer 3, an electron transport layer 4 and a modification layer, wherein the modification layer comprises at least one of a first modification layer 61 and a second modification layer 62; the hole transport layer 2, the perovskite layer 3 and the electron transport layer 4 are stacked in sequence; the first modification layer 61 is located between the perovskite layer 3 and the hole transport layer 2, and the second modification layer 62 is located between the perovskite layer 3 and the electron transport layer 4; the first modification layer 61 and the second modification layer 62 comprise alkylamine salts. The cations and anions in the alkylamine salts can be anchored at the grain boundaries of the perovskite, and at the same time, some cations will form a 2D passivation layer on the surface of the perovskite, thereby enhancing the stability of the interface, thereby reducing the non-radiative recombination in the device (i.e., the perovskite solar cell), making the functional layers of the device more stable, thereby enhancing the stability of the device, achieving the purpose of increasing Voc (i.e., open circuit voltage, which refers to the output voltage of the solar cell when it is open circuit (i.e., no load) under illumination conditions), and improving the device efficiency.

[0031] It can be understood that in the perovskite solar cell of the embodiment of the present application, only the first modified layer (see Figure 1 ), only a second modification layer is provided (refer to Figure 2 ), or a first modification layer and a second modification layer are provided at the same time (refer to Figure 3 ).

[0032] According to the embodiments of the present application, the specific type of alkylamine salt that can be used can be selected according to actual needs. In some specific embodiments, the alkylamine salt includes at least one of octylamine chloride (OACl), phenethylammonium chloride (PEACl), and octylamine iodide (OAI).

[0033] According to an embodiment of the present application, the second modified layer also includes guanidinium halides. In other words, the second modified layer contains both alkylamine salts and guanidinium halides. In the second modified layer, alkylamine salts and guanidinium halides of double-interaction salts are used, and the controllable ion interaction and diffusion make the passivation effect greatly improve the quality of the perovskite layer.

[0034] Specifically, on the one hand, the cations and anions in the alkylamine salt can be anchored at the perovskite grain boundary, interacting with PbI2 at the interface to form a non-perovskite complex that aggregates on the grain surface; on the other hand, through the hydrogen bond interaction between the cations in the alkylamine salt and the cations in the guanidinium halide, the alkylamine salt passivates the grain boundary while slowing down the diffusion of the cations in the alkylamine salt, and obtains a sheet structure of n=2 (n represents the dimension of the perovskite, and n=2 represents a two-dimensional perovskite) on the surface of the perovskite layer, forming a quasi-2D passivation layer, in which the cations in the guanidinium halide can form hydrogen bonds with the cations in the alkylamine salt to produce a supramolecular structure with a larger molecular skeleton, so that the cations in the alkylamine salt exhibit slower diffusion, thereby causing the size of the two-dimensional phase on the upper surface to become wider. In addition, the cations in the guanidino halide diffuse to passivate the main body of the perovskite crystal and suppress the overall defect density of the perovskite layer, while the smaller anions also diffuse into the bulk phase of the 3D perovskite. The diffused anions can thermodynamically stabilize the perovskite structure, passivate the i-vacancies of the perovskite, and enhance the FA + (formamidinium cation) and I - The interaction between the two improves the stability of the FAPbI3 structure and plays a role in passivating the perovskite bulk phase. In summary, these ion diffusions reduce the defect density of the perovskite layer, increase the perovskite particle size, reduce interface defects, and further increase the open circuit voltage (Voc), and the corresponding perovskite solar cells (PSCs) show a significant improvement in performance.

[0035] According to the embodiments of the present application, the guanidinium halides that can be used can be flexibly selected according to actual needs. In some specific embodiments, the guanidinium halides include guanidinium chloride (GACl). As a specific example, the second modified layer contains both octylamine chloride (OACl) and guanidinium chloride (GACl). As a result, the synergistic effect of the two is better, and the surface and bulk of the perovskite can be passivated at the same time. The controllable ion interaction and diffusion make the passivation effect greatly improve the film quality, thereby reducing the non-radiative recombination of the device and improving the device energy conversion efficiency (PCE).

[0036] According to an embodiment of the present application, in order to achieve a better synergistic effect, in the second modified layer, the mass ratio of the alkylamine salt to the guanidinium halide is 1-3:0.5-1.5, specifically 1:0.5, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, etc. By controlling and optimizing the alkylamine salt and the guanidinium halide, a perovskite film with fewer defects and larger grains can be formed, further improving the energy conversion efficiency of the device.

[0037] According to some specific embodiments of the present application, the modified layer includes the first modified layer and the second modified layer, the first modified layer includes the alkylamine salt, and the second modified layer includes the alkylamine salt and the guanidinium halide. Thus, the cations and anions in the alkylamine salt in the first modified layer can be anchored at the grain boundary of the perovskite, and at the same time, some cations will form a 2D passivation layer on the surface, thereby enhancing the stability of the interface, and the synergistic effect of the alkylamine salt and the guanidinium halide in the second modified layer can simultaneously passivate the surface and bulk of the perovskite, greatly improving the quality of the perovskite layer, thereby greatly improving the stability and energy conversion efficiency of the perovskite solar cell.

[0038] According to an embodiment of the present application, the thickness of the first modification layer may be 1 nm to 20 nm, specifically 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, etc. Within this thickness range, it is possible to ensure a better passivation effect on the perovskite phase while stabilizing the interface.

[0039] According to an embodiment of the present application, the thickness of the second modification layer may be 1 nm to 20 nm, specifically 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, etc. Within this thickness range, it is possible to ensure a better passivation effect on the perovskite phase while stabilizing the interface.

[0040] According to an embodiment of the present application, the specific material of the hole transport layer includes but is not limited to a polymer material, an inorganic oxide material, a metal organic framework material, and the like. As an example, the material of the hole transport layer includes at least one of [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACz), 2-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-2PACz), poly-4-carbazolephosphonic acid (Poly-4PACz), 4-(3,6-diphenyl-9H-carbazole-9-yl)butylphosphonic acid (Ph-4PACz), [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz), and [2-(7H-dibenzocarbazole-7-yl)ethyl]phosphonic acid (Ph-2PACz).

[0041] According to an embodiment of the present application, the perovskite layer is mainly composed of an organic metal halide semiconductor, and its chemical formula is ABX3. Wherein, A represents a monovalent organic or inorganic cation, such as methylamine ion CH3NH3 +, Cesium ion Cs + etc.; B represents divalent metal cations, such as lead ion Pb 2+ 、Sn 2+ etc.; X represents a monovalent halogen anion, such as bromide ion Br-, iodide ion I-, etc. Specifically, the perovskite layer has excellent light absorption performance and charge separation ability, can absorb sunlight and generate excitons (electron-hole pairs), thereby realizing photoelectric conversion. As an example, the perovskite layer includes at least one of formamidinium lead iodide perovskite (FAPbI3), methylamine lead iodine (CH3NH3PbI3), cesium lead iodine (CsPbI3), methylamine lead bromide (MAPbBr3), and cesium lead bromide (CsPbBr3).

[0042] According to the embodiments of the present application, the main function of the electron transport layer is to effectively transfer photogenerated electrons from the perovskite active layer to the external circuit, thereby improving the photoelectric conversion efficiency of the battery. The materials of the electron transport layer include, but are not limited to, metal oxides, organic compounds, and composite materials. Specifically, metal oxide electron transport materials include TiO2, ZnO, SnO2, etc.; organic compound electron transport materials include fullerene derivatives (PCBM), C60, etc.; composite materials are materials composed of two or more materials of different properties through physical or chemical methods, such as metal oxide and organic compound composite materials.

[0043] It can be understood that the solar cell according to the embodiment of the present application can have a regular solar cell structure or an inverted solar cell structure. Specifically, the solar cell can also include a transparent conductive substrate, which is located on a side of the hole transport layer away from the perovskite layer (refer to Figure 4 ) or the side of the electron transport layer away from the perovskite layer (refer to Figure 5 ).

[0044] According to an embodiment of the present application, the transparent conductive substrate may be conductive glass. Specifically, the conductive glass may be used as an electrode of a battery to improve the light absorption efficiency and conversion efficiency of the battery; at the same time, it may also provide a protective layer to protect the perovskite layer from environmental factors such as oxidation, water, light, and low temperature, thereby improving the stability and life of the battery. As an example, conductive glass includes but is not limited to transparent conductive oxide glass and glass ceramic materials; wherein transparent conductive oxide glass mainly includes indium tin oxide (ITO) glass and zinc oxide (ZnO) glass; glass ceramic materials include high-temperature ceramic materials composed of materials such as aluminum oxide, silicates, and borates.

[0045] According to the embodiments of the present application, referring to Figure 6 and Figure 7The solar cell may further include a metal electrode 5, which is located on a side of the hole transport layer away from the perovskite layer (refer to Figure 6 ) or the side of the electron transport layer away from the perovskite layer (refer to Figure 7 ). The metal electrode plays the role of collecting and transmitting current in the battery and is an important part of completing the photoelectric conversion process. Specifically, the materials of the metal electrode include but are not limited to silver, copper, gold, etc.

[0046] According to the embodiments of the present application, referring to Figure 8 The perovskite solar cell may further include a buffer layer 7, which is located between the metal electrode 5 and the electron transport layer 4. Thus, the problems of band mismatch, carrier recombination and chemical reaction between interfaces can be improved, thereby improving the charge separation and collection efficiency, and achieving effective improvement of interface and stability problems. Specifically, the specific materials of the buffer layer include but are not limited to bicyclo[1.1.1]pentane, ytterbium oxide, CdS, ZnS and TiO2.

[0047] In the second aspect of the present application, a method for preparing the aforementioned perovskite solar cell is provided. The method comprises the following steps: forming a hole transport layer; forming a perovskite layer on one side of the hole transport layer; forming an electron transport layer on the side of the perovskite layer away from the hole transport layer; the method further comprises at least one of the following steps: forming a first modification layer on the surface of the hole transport layer close to the perovskite layer; forming a second modification layer on the surface of the perovskite layer away from the hole transport layer. The method is simple and convenient to operate, easy to achieve large-scale production, and the prepared perovskite solar cell has good stability and energy conversion efficiency.

[0048] As mentioned above, the perovskite solar cell may be provided with only the first modification layer, only the second modification layer, or both the first modification layer and the second modification layer. Accordingly, the steps for preparing the perovskite solar cell are also different.

[0049] In some embodiments, only a first modified layer is provided in the perovskite solar cell, which can be prepared by the following steps: forming a hole transport layer; forming a first modified layer on the surface of the hole transport layer; forming a perovskite layer on a side of the first modified layer away from the hole transport layer; and forming an electron transport layer on a side of the perovskite layer away from the transparent conductive substrate.

[0050] In some embodiments, only a second modified layer is provided in the perovskite solar cell, which can be prepared by the following steps: forming a hole transport layer; forming a perovskite layer on one side of the hole transport layer; forming a second modified layer on a surface of the perovskite layer away from the hole transport layer; and forming an electron transport layer on a side of the second modified layer away from the hole transport layer.

[0051] In some embodiments, a first modified layer and a second modified layer are simultaneously provided in a perovskite solar cell, which can be prepared by the following steps: forming a hole transport layer; forming a first modified layer on the surface of the hole transport layer; forming a perovskite layer on a side of the first modified layer away from the hole transport layer; forming a second modified layer on a surface of the perovskite layer away from the hole transport layer; and forming an electron transport layer on a side of the second modified layer away from the hole transport layer.

[0052] According to an embodiment of the present application, the hole transport layer can be prepared by a spin coating method. Specifically, the raw material for forming the hole transport layer can be dissolved in a solvent, and then the obtained solution can be spin coated on a transparent conductive substrate and annealed to obtain the hole transport layer. The raw material for forming the hole transport layer is as described above, and will not be described in detail here. The solvent used includes but is not limited to sewage ethanol, etc.

[0053] As an example, the hole transport layer can be prepared by the following steps: dissolving Me-4PACz in anhydrous ethanol to obtain a hole transport layer solution with a concentration of 0.1 mg / ml to 1 mg / ml, and then spin coating the hole transport layer solution on a transparent conductive substrate, wherein the spin coating speed can be 2000 rpm to 4000 rpm, and the spin coating time can be 20s to 40s; then static annealing is performed to obtain the hole transport layer, wherein the annealing temperature can be 80°C to 120°C and the annealing time can be 5min to 15min.

[0054] According to an embodiment of the present application, the first modification layer can be formed by a spin coating method. Specifically, the alkylamine salt can be dissolved in a solvent, and then the obtained first modification layer solution can be spin coated on the hole transport layer to obtain the first modification layer.

[0055] According to some specific embodiments of the present application, the first modification layer is formed by the following steps: spin coating a first alkylamine salt solution with a concentration of 0.2 mg / ml to 0.4 mg / ml on the hole transport layer to obtain a first modification layer, wherein the spin coating speed can be 3000 rpm to 5000 rpm, and the spin coating time can be 20s to 40s.

[0056] It can be understood that the alkylamine salt forming the first modification layer can be consistent with the above description, which will not be repeated here; the solvent used to prepare the first modification layer solution includes but is not limited to N,N-dimethylformamide (DMF).

[0057] According to an embodiment of the present application, the perovskite layer can be prepared by a two-step spin coating and interdiffusion method. Specifically, the first step is the deposition of the PbI2 layer, which can specifically include spin coating the PbI2 solution on the HTL layer, the spin coating speed can be 1000rpm~2000rpm, and the spin coating time can be 20s~40s; then annealing at 50℃~100℃ for 30s~90s to form a yellow transparent layer. The second step can include: spin coating the amine salt solution on the PbI2 layer, the spin coating speed can be 1000rpm~2000rpm, and the spin coating time can be 20s~40s. In this step, a layer of PbI2 film is first spin coated, and then the FAI solution is spin coated on the PbI2 film. The FAI solution penetrates downward into the interior of the PbI2 film, and FAI reacts with PbI2 to form FAPbI3 perovskite, and the residual solvent is removed by annealing.

[0058] According to an embodiment of the present application, the solvent used to prepare the PbI2 solution includes but is not limited to at least one of DMF and dimethyl sulfoxide (DMSO). As an example, it can be a mixed solvent of DMF and DMSO.

[0059] As an example, the perovskite layer can be formed as follows: PbI2 solution (691.55 mg / ml dissolved in a mixed solvent of DMF & DMSO (volume ratio 9:1), and 4 mg of RbCl was added per 1 ml) at 20 μL / cm 2 The HTL layer was fully coated with an amount of 1700 rpm spin coating for 30 s, and then annealed at 70 ° C for 1 min to form a yellow transparent layer; then an ammonium amine salt solution (FAI (90 mg), MACl (10 mg) dissolved in 1 mL isopropanol (IPA)) was coated at 20 μL / cm 2 An amount of is dropped on the PbI2 layer and spin-coated at a speed of 1800 rpm for 40 s to obtain a perovskite layer.

[0060] According to an embodiment of the present application, the second modification layer can also be formed by a spin coating method. Specifically, an alkylamine salt, or an alkylamine salt and a guanidinium halide salt can be dissolved in a solvent to obtain a second modification layer solution, and then the modification layer solution is spin coated on the perovskite layer, and annealed at 80°C to 120°C for 1min to 5min to obtain the second modification layer, wherein the spin coating speed can be 4000rpm to 6000rpm, and the spin coating time can be 20s to 30s.

[0061] In some specific embodiments, the second modification layer is formed by the following steps: preparing a second alkylamine salt solution with a concentration of 1 mg / ml to 3 mg / ml, spin coating it on the perovskite layer at a rotation speed of 4000 rpm to 6000 rpm for 20s to 30s, and annealing at 80°C to 120°C for 1min to 5min.

[0062] In some other specific embodiments, the second modification layer is formed by the following steps: preparing a mixed solution with an alkylamine salt concentration of 1 mg / ml to 3 mg / ml and a guanidinium halide concentration of 0.5 mg / ml to 1.5 mg / ml, spin coating the solution on the perovskite layer at a rotation speed of 4000 rpm to 6000 rpm for 20s to 30s, and annealing at 80°C to 120°C for 1min to 5min.

[0063] According to an embodiment of the present application, the electron transport layer can be formed by a vacuum evaporation method. Specifically, a vacuum evaporation device can be used to control the vacuum degree to 3×10 -4 Pa is heated to 500℃~650℃, and a C layer with a thickness of 10nm~50nm is deposited. 60 .

[0064] According to an embodiment of the present application, the solar cell further comprises a transparent conductive substrate, and the transparent conductive substrate is located on a side of the hole transport layer away from the perovskite layer or a side of the electron transport layer away from the perovskite layer. Specifically, the transparent conductive substrate can be purchased directly or prepared by itself, and the specific preparation steps and parameters can be carried out with reference to conventional techniques, and this application does not impose any special restrictions.

[0065] In some embodiments, the hole transport layer can be formed on one side of the transparent conductive substrate. Before preparing the hole transport layer, the transparent conductive substrate can be cleaned in advance. As an example, it can be wiped with detergent first, and then ultrasonically treated in detergent water, ultrapure water, anhydrous ethanol, and acetone for 5 minutes to 15 minutes, wherein the ultrapure water can be washed twice, and the transparent conductive substrate after the cleaning treatment can be stored in alcohol.

[0066] According to an embodiment of the present application, the solar cell may further include a metal electrode, which may be formed by evaporation. Specifically, evaporation may be performed in steps to form a metal electrode that meets the requirements. Specifically, a thin layer of metal may be formed by evaporation at a slower speed, and then the evaporation speed may be gradually increased until a metal electrode of a predetermined thickness is obtained. Thus, a metal layer with a higher density may be formed in advance, which forms an ohmic contact with the electron transport layer and has better interface stability, and subsequent evaporation at a faster speed may effectively improve efficiency.

[0067] As an example, a metal electrode can be prepared by the following steps: 3 silver particles are placed in an evaporation boat, the product prepared in the previous step is placed on a mask plate, and fixed to a substrate plate; The first metal layer with a thickness of 10nm to 30nm is evaporated at a rate of The second metal layer with a thickness of 30nm to 50nm is evaporated at a rate of The third metal layer with a thickness of 50nm to 70nm is evaporated at a rate. The first metal layer, the second metal layer and the third metal layer together constitute a metal electrode, and the total thickness can be 90nm to 150nm.

[0068] As mentioned above, the perovskite solar cell may further include a buffer layer, the buffer layer being located between the metal electrode and the electron transport layer. Accordingly, the method for preparing a perovskite solar cell may include: forming a buffer layer on one side of the electron transport layer and the transparent conductive substrate.

[0069] Specifically, the buffer layer can be formed by spin coating. Specifically, the raw materials for forming the buffer layer can be dissolved in a solvent to prepare a buffer layer solution, and then the buffer layer solution is spin coated on the electron transport layer and annealed at 50°C to 100°C for 1 min to 10 min to obtain the buffer layer.

[0070] As an example, the buffer layer can be prepared by the following steps: dissolve 0.1 mg to 1 mg of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) in 0.5 ml to 1.5 ml of IPA to obtain a buffer layer solution, take 50 μl to 70 μl of the buffer layer solution and dynamically spin coat it at a rotation speed of 2000 rpm to 6000 rpm for 20 s to 40 s, and then anneal at 50°C to 100°C for 1 min to 10 min.

[0071] In a third aspect of the present application, a solar cell assembly is provided. According to an embodiment of the present application, the solar cell and assembly include the solar cell described above or the solar cell prepared by the method described above. The solar cell assembly has better stability and higher energy conversion efficiency.

[0072] In a fourth aspect of the present application, an electrical device is provided. According to an embodiment of the present application, the electrical device includes the aforementioned perovskite solar cell or the perovskite solar cell prepared by the aforementioned method. The electrical device has all the features and advantages of the aforementioned perovskite solar cell, which will not be described one by one here.

[0073] The embodiments of the present application are described in detail below.

[0074] Example 1

[0075] Glass cleaning: FTO glass was first wiped with detergent, then ultrasonically treated with detergent water, ultrapure water, anhydrous ethanol, and acetone solution for 10 min, washed twice with ultrapure water, and stored in alcohol.

[0076] Preparation of HTL layer: Me-4PACz solution (0.5 mg / ml dissolved in anhydrous ethanol) was used as the HTL layer solution, spin-coated at 3000 rpm for 30 s, and annealed at 100 °C for 10 min;

[0077] First modification layer: 0.3 mg OACl was dissolved in 1 ml DMF and then spin-coated on the HTL at 4000 rpm for 30 s;

[0078] Preparation of perovskite layer: 80 μL of PbI2 solution (691.55 mg / ml dissolved in a mixed solution of DMF & DMSO (9:1), and 4 mg of RbCl was added per 1 ml) was spread on the HTL layer, spin-coated at 1700 rpm for 30 s, and annealed at 70 ° C for 1 min to form a yellow transparent layer. Then 80 μL of amine salt solution (FAI (90 mg), MACl (10 mg) dissolved in 1 mL of isopropanol (IPA)) was dropped on the PbI2 layer and spin-coated at 1800 rpm for 40 s;

[0079] Second modification layer: 1 mg of guanidine chloride (GACl) and 3 mg of OACl were dissolved in 1 ml of IPA, 20 μl of the mixed solution was spin-coated on the perovskite film at 5000 rpm for 25 seconds, and then annealed at 100 °C for 3 minutes;

[0080] Buffer layer: 0.5 mg BCP was dissolved in 1 ml IPA, 70 μl of the solution was dynamically spin-coated at 4000 rpm for 30 s, and then annealed at 70 °C for 3 min;

[0081] Metal electrode: Place three silver particles into the evaporation boat, place the sample prepared in the above steps on the mask, fix it on the substrate plate, and heat it at a rate of Evaporate a 20nm thick silver layer and then Evaporate a 40nm thick silver layer, and then A silver layer with a thickness of 60 nm was evaporated to obtain a silver electrode with a total thickness of 120 nm.

[0082] Example 2

[0083] The same as Example 1, except that when preparing the second modification layer, 1 mg of guanidine chloride (GACl) and 1 mg of OACl were dissolved in 1 ml of IPA.

[0084] Example 3

[0085] The same as Example 1, except that when preparing the second modification layer, 1 mg of guanidine chloride (GACl) and 1 mg of OACl were dissolved in 2 ml of IPA.

[0086] Example 4

[0087] The same as Example 1, except that: when preparing the second modification layer, 0.5 mg of guanidine chloride (GACl) and 2 mg of OACl were dissolved in 2 ml of IPA.

[0088] Example 5

[0089] The same as Example 1, except that when preparing the second modification layer, 1.5 mg of guanidine chloride (GACl) and 2 mg of OACl were dissolved in 2 ml of IPA.

[0090] Example 6

[0091] The same as Example 3, except that when preparing the first modification layer, 0.1 mg of PEACl was dissolved in 1 ml of DMF.

[0092] Example 7

[0093] The same as Example 3, except that when preparing the first modification layer, 0.2 mg of PEACl was dissolved in 1 ml of DMF.

[0094] Example 8

[0095] The same as Example 3, except that when preparing the first modification layer, 0.3 mg of PEACl was dissolved in 1 ml of DMF.

[0096] Example 9

[0097] The same as Example 3, except that when preparing the first modification layer, 0.4 mg of PEACl was dissolved in 1 ml of DMF.

[0098] Example 10

[0099] The same as Example 3, except that when preparing the first modification layer, 0.2 mg OACl was dissolved in 1 ml DMF.

[0100] Embodiment 11

[0101] The same as Example 3, except that when preparing the first modification layer, 0.4 mg OACl was dissolved in 1 ml DMF.

[0102] Example 12

[0103] Same as Example 1, except that there is no second modification layer.

[0104] Example 13

[0105] Same as Example 3, except that there is no first modification layer.

[0106] Embodiment 14

[0107] Same as Example 8, except that there is no second modification layer.

[0108] Embodiment 15

[0109] The same as Example 1, except that when preparing the second modification layer, 3 mg of OACl was dissolved in 2 ml of IPA.

[0110] Example 16

[0111] Same as Example 13, except that guanidine chloride (GACl) was not added when preparing the second modification layer.

[0112] Comparative Example 1

[0113] Same as Example 1, except that there is no first modification layer and second modification layer.

[0114] Comparative Example 2

[0115] Same as Comparative Example 1, except that 2 mg / ml OACl was added to the PbI2 solution.

[0116] Comparative Example 3

[0117] Same as Comparative Example 1, except that 2 mg / ml GACl was added to the PbI2 solution.

[0118] Performance Testing:

[0119] Volt-ampere-voltage characteristic curve (IV) test

[0120] In a standard atmospheric pressure, air environment (T = 20 ℃ ~ 30 ℃, RH% = 40% ± 10%), AM1.5G one sun JV performance test, the test results are shown in Table 1, the test results of Example 3 and Comparative Example 1 are shown in the figure Fig. 9 .

[0121] Table 1

[0122]

[0123]

[0124] Note: In Example 1, the column “GACl / OACl” in the substance type and the column “1+3” in the concentration of the second modification layer indicate that the concentration of GACl is 1 mg / ml and the concentration of OACl is 3 mg / ml. Similar descriptions in other examples have similar meanings.

[0125] From the data in Table 1, it can be seen that the formation of a modification layer by alkylamine salts can better passivate perovskite, improve the stability and energy conversion efficiency of perovskite solar cells, and further through the synergistic effect of alkylamine salts and guanidinium halides, the passivation effect can be further enhanced, and the stability and energy conversion efficiency of perovskite solar cells are further improved.

[0126] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0127] 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.

[0128] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0129] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A perovskite solar cell, characterized in that: It includes a hole transport layer, a perovskite layer, an electron transport layer and a modification layer, wherein the modification layer includes at least one of a first modification layer and a second modification layer; The hole transport layer, the perovskite layer, and the electron transport layer are stacked in sequence; The first modified layer is located between the perovskite layer and the hole transport layer, and the second modified layer is located between the perovskite layer and the electron transport layer; The first modified layer and the second modified layer include an alkylamine salt.

2. The perovskite solar cell according to claim 1, characterized in that The alkylamine salt includes at least one of octylamine chloride, phenethylammonium chloride and octylamine iodide.

3. The perovskite solar cell according to claim 1, characterized in that The second modification layer also includes guanidinium halogenate.

4. The perovskite solar cell according to claim 3, characterized in that: The guanidinium halide salt includes guanidinium chloride.

5. The perovskite solar cell according to claim 4, characterized in that: In the second modified layer, the mass ratio of the alkylamine salt to the guanidinium halogen acid salt is 1-3:0.5-1.

5.

6. The perovskite solar cell according to any one of claims 1 to 5, characterized in that The modified layer includes the first modified layer and the second modified layer, the first modified layer includes the alkylamine salt, and the second modified layer includes the alkylamine salt and a guanidinium halide salt.

7. The perovskite solar cell according to any one of claims 1 to 6, characterized in that The thickness of the first modified layer is 1 nm to 20 nm; and / or The thickness of the second modified layer is 1 nm to 20 nm.

8. The perovskite solar cell according to claim 1, characterized in that: The invention also includes a transparent conductive substrate, wherein the transparent conductive substrate is located on a side of the hole transport layer away from the perovskite layer or a side of the electron transport layer away from the perovskite layer.

9. A method for preparing a perovskite solar cell according to any one of claims 1 to 8, characterized in that: include: forming a hole transport layer; forming a perovskite layer on one side of the hole transport layer; forming an electron transport layer on a side of the perovskite layer away from the hole transport layer; The method further comprises at least one of the following steps: forming a first modified layer on a surface of the hole transport layer close to the perovskite layer; A second modification layer is formed on a surface of the perovskite layer away from the hole transport layer.

10. The method according to claim 9, characterized in that The hole transport layer, the first modified layer, the perovskite layer, the second modified layer and the electron transport layer are formed by a spin coating method.

11. The method according to claim 9, characterized in that The first modified layer is formed by the following steps: A first alkylamine salt solution with a concentration of 0.2 mg / ml to 0.4 mg / ml is prepared and spin-coated on the hole transport layer at a rotation speed of 3000 rpm to 5000 rpm for 20 s to 40 s.

12. The method according to claim 9, characterized in that The second modified layer is formed by any of the following steps: Prepare a second alkylamine salt solution with a concentration of 1 mg / ml to 3 mg / ml, spin-coat it on the perovskite layer at a speed of 4000 rpm to 6000 rpm for 20 s to 30 s, and anneal at 80° C. to 120° C. for 1 min to 5 min; or, A mixed solution with an alkylamine salt concentration of 1 mg / ml to 3 mg / ml and a guanidinium halide salt concentration of 0.5 mg / ml to 1.5 mg / ml is prepared, spin-coated on the perovskite layer at a rotation speed of 4000 rpm to 6000 rpm for 20 s to 30 s, and annealed at 80° C. to 120° C. for 1 min to 5 min.

13. A solar cell module, characterized in that: A perovskite solar cell comprising the perovskite solar cell according to any one of claims 1 to 8.

14. An electrical device, characterized in that: The invention comprises the perovskite solar cell according to any one of claims 1 to 8, the perovskite solar cell prepared by the method according to any one of claims 9 to 12, or the solar cell module according to claim 13.

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