Perovskite cell, preparation method thereof and laminated cell

Abstract

The embodiment of the invention provides a perovskite cell, a preparation method thereof and a laminated cell. The perovskite cell comprises a conductive substrate, an inorganic hole transport layer, an organic hole transport layer, a perovskite absorption layer, an electron transport layer and an electrode which are sequentially arranged in a preset direction. Wherein the organic hole transport layer comprises a first hole transport material and a second hole transport material; the first hole transport material comprises a carbazole hole material with a phosphate group; the second hole transport material includes (2-(pyrene-1-yl) ethyl) phosphonic acid. The perovskite cell provided by the embodiment of the invention has a good buried bottom passivation effect, so that energy levels between the hole transport layer and the perovskite absorption layer can be better matched, the carrier extraction rate is improved, the overall cell parameters are improved, and the problem of poor performance of the perovskite cell is solved. The embodiment of the invention also provides a preparation method of the perovskite cell and a laminated cell applying the perovskite cell.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the technical field of perovskite solar cells, and in particular to a perovskite cell, a preparation method thereof, and a stacked cell. Background Art

[0002] Perovskite materials have attracted widespread attention from researchers due to their excellent optoelectronic properties, such as ideal and tunable bandgap width, high absorption coefficient, low electron-hole pair binding energy, high free carrier mobility and bipolar carrier transport characteristics.

[0003] As the photoelectric conversion efficiency of perovskite solar cells continues to improve, researchers have also tried different combinations to improve the theoretical efficiency of perovskite solar cells. However, there are still some problems with the current perovskite cell process, resulting in the need for further improvement in the photoelectric conversion efficiency of perovskite cells.

[0004] At present, how to improve the photoelectric conversion efficiency of perovskite cells has become an important research topic. Summary of the Invention

[0005] The embodiments of the present application provide a perovskite cell, a preparation method thereof, and a stacked cell, which are at least beneficial to improving the photoelectric conversion efficiency of the perovskite cell.

[0006] An embodiment of the present application provides a perovskite cell, comprising: a conductive substrate, an inorganic hole transport layer, an organic hole transport layer, a perovskite absorption layer, an electron transport layer and an electrode arranged in sequence in a preset direction, wherein the organic hole transport layer comprises a first hole transport material and a second hole transport material; the first hole transport material comprises a carbazole-type hole material having a phosphate group; and the second hole transport material comprises (2-(pyrene-1-yl)ethyl)phosphonic acid.

[0007] Optionally, the mass ratio of the first hole transport material to the second hole transport material is (1:1) to (1:5).

[0008] Optionally, the first hole transport material includes at least one of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, methoxy-modified [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, [4-(9H-carbazol-9-yl)phenyl]phosphonic acid, and methyl-modified [4-(9H-carbazol-9-yl)phenyl]phosphonic acid.

[0009] Optionally, the thickness of the organic hole transport layer is 1 nm to 2 nm.

[0010] Optionally, the thickness of the perovskite absorption layer is 500 nm to 650 nm.

[0011] According to some embodiments of the present disclosure, on the other hand, the embodiments of the present disclosure further provide a method for preparing a perovskite battery, comprising: providing a conductive substrate, and sequentially forming an inorganic hole transport layer, an organic hole transport layer, a perovskite absorption layer, an electron transport layer and an electrode on the conductive substrate in a preset direction; wherein the preparation step of the organic hole transport layer comprises: preparing a mixed solution comprising a first hole transport material and a second hole transport material, wherein the first hole transport material is a carbazole-type hole material having a phosphate group, and the second hole transport material is (2-(pyrene-1-yl)ethyl)phosphonic acid; coating the mixed solution on the surface of the inorganic hole transport layer, and forming the organic hole transport layer after a first annealing treatment; coating a perovskite precursor solution on the surface of the organic hole transport layer, and forming the perovskite absorption layer after a second annealing treatment.

[0012] Optionally, the step of configuring the mixed solution includes: mixing the first hole transport material and a first solvent to prepare a first solution, wherein the first hole transport material in the first solution has a first concentration, and the first concentration is 0.6 g / L-1.5 g / L, wherein the first hole transport material includes the [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, methoxy-modified [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(9H-carbazole-9-yl)phenyl]phosphine The method comprises the following steps: mixing the second hole transport material and the second solvent to prepare a second solution, wherein the second hole transport material includes (2-(pyrene-1-yl)ethyl)phosphonic acid, and the second hole transport material has a second concentration in the second solution, and the second concentration is 0.6 g / L-1.5 g / L; mixing the first solution and the second solution in a volume ratio of (1:1) to (1:5) to obtain the mixed solution.

[0013] Optionally, the first concentration is the same as the second concentration.

[0014] Optionally, the first solvent and the second solvent are each independently selected from at least one of ethanol and isopropanol.

[0015] Optionally, the process parameters of the first annealing treatment include: an annealing temperature of 100° C. to 140° C., and an annealing time of 8 min to 15 min.

[0016] Optionally, coating the mixed solution on the surface of the inorganic hole transport layer includes: coating the mixed solution by a spin coating method, wherein the rotation speed of the spin coating method is 4000 rpm to 5000 rpm and the duration is 20 seconds to 30 seconds.

[0017] Optionally, a perovskite precursor solution is coated on the surface of the organic hole transport layer, including: coating the perovskite precursor solution by a spin coating method, and the rotation speed of the spin coating method is 3000rpm~5000rpm, and the duration is 20 seconds~30 seconds; the process parameters of the second annealing treatment include: an annealing temperature of 90℃~100℃, and an annealing time of 8min~15min.

[0018] According to some embodiments of the present disclosure, on the other hand, the embodiments of the present disclosure further provide a stacked cell, comprising: a top cell, wherein the top cell is the perovskite cell described in any one of the above items; and a crystalline silicon bottom cell, wherein the crystalline silicon bottom cell is located on a side of the transparent conductive substrate of the perovskite cell away from the electrode.

[0019] According to some embodiments of the present disclosure, on the other hand, the embodiments of the present disclosure further provide a photovoltaic assembly, comprising: a plurality of the above-mentioned stacked cells; a connecting component, the connecting component being used to connect adjacent stacked cells; an adhesive film, the adhesive film covering the surface of the stacked cells; and a cover plate, the cover plate being located on the surface of the adhesive film away from the stacked cells.

[0020] The embodiment of the present application provides a perovskite cell, which includes a conductive substrate, an inorganic hole transport layer, an organic hole transport layer, a perovskite absorption layer, an electron transport layer and an electrode arranged in sequence in a preset direction. The organic hole transport layer includes a first hole transport material and a second hole transport material; the first hole transport material includes a carbazole hole material having a phosphate group; and the second hole transport material includes (2-(pyrene-1-yl)ethyl)phosphonic acid. The mixed SAM (Self-Assembled Monolayers) perovskite cell has a good bottom passivation effect, which can make the energy levels between the hole transport layer (HTL, Hole Transport Layer) and the perovskite absorption layer (PVK, Perovskite) more matched, thereby increasing the carrier extraction rate, thereby reducing non-radiative recombination, improving the overall cell parameters, and helping to improve the photoelectric conversion efficiency of the perovskite cell. The embodiment of the present application also provides a method for preparing the above-mentioned perovskite cell, and a stacked cell using the above-mentioned perovskite cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplified descriptions do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the drawings do not constitute a scale limitation. In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the traditional technology, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 Schematic diagram of the cross-sectional structure of a perovskite battery;

[0023] Figure 2 Flowchart of the perovskite battery preparation method.

[0024] Legend: 1-electrode; 2-conductive substrate; 301-inorganic hole transport layer; 302-organic hole transport layer; 4-perovskite absorption layer; 5-electron transport layer; 6-IZO film layer. DETAILED DESCRIPTION

[0025] As can be seen from the background art, the photoelectric conversion efficiency of perovskite cells in related technologies needs to be improved.

[0026] In the field of perovskite cells, especially in the research and development of perovskite-silicon (Si) stacked cells, despite its high theoretical efficiency and wide spectral response range, the actual performance improvement and stability assurance still face many challenges. Among them, the problem of poor interface contact between the hole transport layer and the perovskite absorption layer is particularly prominent, becoming a key bottleneck restricting the further optimization of perovskite cell performance. Analysis found that, in perovskite cells, there are problems such as uneven contact between the Si substrate and the perovskite contact interface, which will lead to energy loss at the interface between the hole transport layer (HTL) and the perovskite absorption layer in the battery, thereby making the open-circuit voltage (Voc) of the battery low, affecting the photoelectric conversion efficiency of the perovskite battery, and thus affecting the overall performance of the battery.

[0027] From the perspective of interface properties, the surface of the Si substrate inevitably has a certain degree of roughness, surface defects, and chemical inhomogeneity due to factors such as the preparation process and the intrinsic properties of the material. When the perovskite absorber layer is deposited directly on it, this non-ideal interface condition makes it difficult for the perovskite material to form a uniform, tight, and high-quality contact with the Si substrate. Specifically, a large number of charge traps and recombination centers will appear at the interface. These defect states will capture carriers, increase the probability of carrier recombination at the interface, and thus significantly reduce the carrier collection efficiency. In terms of hole transport, the interface interaction between traditional hole transport layer materials and the perovskite absorber layer is weak and cannot effectively passivate interface defects, resulting in a distortion of the energy level structure at the interface. There is an uneven contact between the Si substrate and the perovskite contact interface, which leads to energy loss at the interface between the hole transport layer and the perovskite absorber layer in the perovskite battery, resulting in a low open circuit voltage of the battery. Specifically, this energy level mismatch phenomenon requires holes to overcome additional potential barriers during the transmission process from the perovskite absorption layer to the hole transport layer, increasing energy loss and leading to a lower open circuit voltage (Voc) of the perovskite cell. Voc is one of the key parameters for measuring the performance of solar cells. Its reduction directly limits the improvement of the cell's photoelectric conversion efficiency and significantly reduces the output power of the cell under actual working conditions. Uneven contact also affects the crystallization quality of the perovskite absorption layer. At the non-uniform interface, the nucleation and growth process of the perovskite precursor solution is disturbed, making it difficult to form a uniform and dense perovskite film. The perovskite absorption layer with poor crystallization quality contains a large number of grain boundary defects and impurities, which further aggravates the recombination loss of carriers, reduces the fill factor (FF) and short-circuit current density (Jsc) of the cell, and ultimately affects the overall performance of the cell.

[0028] As the photoelectric conversion efficiency of perovskite solar cells continues to improve, researchers are also trying different combinations to improve the theoretical efficiency of perovskite cells. Among them, perovskite-Si tandem cells are one of the most promising directions, and the power conversion efficiency (PCE) of such tandem cells has reached 34.6%. However, the current perovskite tandem cell process is unstable, resulting in large fluctuations in efficiency. The main reason is that there are problems such as uneven contact between the Si substrate and the perovskite contact interface, which leads to energy loss at the interface between the hole transport layer (HTL) and the perovskite absorber layer in the tandem cell, resulting in a low Voc of the tandem cell. Therefore, adjusting the HTL energy level to match the perovskite valence band is an effective way to improve device performance.

[0029] At least to improve or solve the above technical problems, the embodiment of the present application provides a perovskite cell, in which a conductive base layer, an inorganic hole transport layer, an organic hole transport layer, a perovskite absorption layer, an electron transport layer and an electrode are sequentially arranged in a preset direction. The organic hole transport layer adopts a mixed hole transport material. The use of a mixed hole transport layer perovskite cell and a preparation method can not only effectively improve the interface contact between the hole transport layer and the perovskite absorption layer, passivate the lower interface, and make the buried bottom interface smoother, which is conducive to obtaining a high-quality, uniform perovskite film on the structure, but also improve its energy level, so that the energy level between HTL and PVK is more matched, thereby facilitating the transmission of carriers. This structure can improve the photoelectric conversion efficiency of the perovskite cell.

[0030] In the organic hole transport layer, (2-(pyrene-1-yl)ethyl)phosphonic acid (Py3) material with a phosphate group and a carbazole-type hole material with a phosphate group are mixed in a certain proportion as a hole transport precursor and spin-coated on a Si wafer. This not only makes the perovskite precursor solution easier to spread and obtain a smooth perovskite absorption layer, but also makes the energy levels between HTL and PVK more matched, reduces the interface potential barrier, reduces the open-circuit voltage loss, and improves the stability and overall performance of the device.

[0031] Specifically, the organic hole transport layer uses a mixed hole transport material, which can improve the wettability of the perovskite precursor by regulating the surface energy, promote the nucleation of uniform perovskite films, optimize energy level matching, and reduce interface barriers. The conjugated structure of the pyrene group can enhance the hole mobility, while the phosphate group passivates the interface defects and inhibits non-radiative recombination, thereby improving the overall performance of the stacked battery.

[0032] The following embodiments are described in detail, with examples illustrated in the accompanying drawings. When the following description refers to the drawings, identical numbers in different figures represent identical or similar elements unless otherwise indicated. The embodiments described in the following embodiments are not intended to represent all possible implementations consistent with the present application. They are merely examples of systems and methods consistent with certain aspects of the present application, as detailed in the claims.

[0033] Figure 1 A schematic diagram of the cross-sectional structure of a perovskite battery provided in an embodiment of the present application.

[0034] refer to Figure 1 The perovskite cell includes a conductive substrate 2, an inorganic hole transport layer 301, an organic hole transport layer 302, a perovskite absorption layer 4, an electron transport layer 5, an IZO film layer 6 and an electrode 1 arranged in sequence in a preset direction.

[0035] The organic hole transport layer includes a first hole transport material and a second hole transport material; the first hole transport material includes a carbazole-based hole transport material having a phosphate group; the second hole transport material includes (2-(pyrene-1-yl)ethyl)phosphonic acid. The organic hole transport layer includes a mixed hole transport material, which can provide the perovskite cell with good bottom passivation, better match the energy levels between the HTL and PVK, increase the carrier extraction rate, thereby reducing non-radiative recombination, improving overall cell parameters, and promoting the photoelectric conversion efficiency of the perovskite cell.

[0036] In the perovskite cell structure, the conductive substrate plays a key role in support and conductivity. Conductive substrates include fluorine-doped tin oxide glass, indium-doped tin oxide glass, and flexible conductive substrates.

[0037] In perovskite cells, there are a variety of inorganic hole transport materials to choose from, including nickel oxide, cuprous thiocyanate, cuprous oxide, and cobalt oxide. These materials have excellent hole transport performance and stability. Their primary function is to efficiently transport holes, collecting and transferring holes generated in the perovskite absorber layer to the conductive substrate. Typically, the thickness of the inorganic hole transport layer ranges from 10 to 50 nm. A suitable inorganic hole transport layer thickness ensures efficient hole transport while avoiding the increased resistance and light absorption losses associated with an overly thick inorganic hole transport layer.

[0038] The organic hole transport layer in the embodiment of the present application includes a first hole transport material (a carbazole-type hole material with a phosphate group) and a second hole transport material ((2-(pyrene-1-yl)ethyl)phosphonic acid). On the one hand, these materials can further optimize the transport of holes, increase the carrier extraction rate, and reduce non-radiative recombination; on the other hand, they have a good bottom passivation effect, so that the energy levels between the hole transport layer (HTL) and the perovskite absorption layer (PVK) are more matched, the interface performance is improved, and the energy loss at the interface is reduced, thereby improving the overall performance of the battery. The organic hole transport layer and the inorganic hole transport layer together constitute a hole transport system, and the synergistic effect improves the hole transport efficiency; the organic hole transport layer is in direct contact with the perovskite absorption layer, and its good interface matching and passivation effect help to improve the photoelectric conversion performance of the perovskite absorption layer.

[0039] An inorganic hole transport layer is provided as an intermediate layer between the conductive substrate and the organic hole transport layer. The inorganic hole transport layer acts as a "bridge," enhancing the adhesion and uniformity of the organic hole transport layer on the surface of the conductive substrate. The inorganic hole transport layer can provide metal sites that can anchor the first and second hole transport materials in the organic hole transport layer. This anchoring effect allows the first and second hole transport materials to be tightly bonded to the surface of the conductive substrate, filling the microscopic uneven areas on the surface of the conductive substrate. Furthermore, the organic hole transport layer can be better spread on the substrate surface, forming a continuous, uniform film, reducing gaps and defects at the interface, thereby effectively improving the interface contact quality.

[0040] The first hole-transporting material, a carbazole-based hole-transporting material with phosphate groups, can undergo an anchoring reaction with the conductive substrates Si and NiOx. However, this anchoring ability is insufficient to deposit a uniformly thick PVK film on the conductive substrate. A second hole-transporting material, (2-(pyrene-1-yl)ethyl)phosphonic acid, also with phosphate groups, is mixed with the first hole-transporting material. Both hole-transporting materials contain phosphate groups. When these materials are mixed and placed in contact with a conductive substrate (such as Si and NiOx), the phosphate groups compete for active sites on the substrate surface. Because the phosphate groups of each material differ in their binding mode and affinity with the substrate, this competition forces them to bind to the substrate at different angles and in different ways, increasing the overall number and strength of binding sites. This results in a tighter and more uniform bond to the conductive substrate, resulting in a stronger anchoring effect than when either hole-transporting material is used alone. This synergistic effect helps form a more uniform hole-transporting layer on the conductive substrate, providing a better foundation for the subsequent deposition of a uniformly thick PVK film. At the same time, mixing two hole transport materials can improve the wettability of perovskite precursors by regulating surface energy, promote the nucleation of uniform perovskite films, optimize energy level matching, and reduce interface barriers. The conjugated structure of the pyrene group can enhance hole mobility, while the phosphate group passivates interface defects and inhibits non-radiative recombination, thereby improving the overall performance of perovskite cells.

[0041] The main material of the perovskite absorption layer is a perovskite-type compound, such as methylammonium lead iodide (CH3NH3PbI3). This type of material has excellent light absorption and photoelectric conversion properties. It is in close contact with the organic hole transport layer, and the good interface properties facilitate the effective extraction and transport of holes. It works together with the electron transport layer to achieve effective separation and transport of electrons and holes. Common electron transport layer materials include titanium dioxide (TiO2) and zinc oxide (ZnO), which achieve efficient electron transmission, collecting and transmitting electrons generated by the perovskite absorption layer to the electrode. Electrode materials include gold (Au) and silver (Ag). These metals have good conductivity and stability. The electrode serves as the charge output end of the battery, collecting electrons transmitted from the electron transport layer and exporting them to the external circuit to achieve the battery's power output.

[0042] Common electron transport layer materials include titanium dioxide (TiO2) and zinc oxide (ZnO), which have excellent electron transport performance and stability. The main function of the electron transport layer is to efficiently transport electrons, collect the electrons generated by the perovskite absorption layer, and further transmit them to the electrode. The electron transport layer is in close contact with the perovskite absorption layer, and good interface performance helps electrons to be smoothly transferred from the perovskite absorption layer to the electron transport layer, and at the same time, it works together with the perovskite absorption layer to achieve effective separation and transmission of electrons and holes. In addition, the electron transport layer also works with adjacent layers such as the IZO film layer. The IZO film layer collects electrons transmitted from the electron transport layer and further conducts them to ensure that the electrons can smoothly reach the electrode and complete the charge transfer process inside the battery, thereby ensuring the overall performance of the perovskite battery.

[0043] IZO, or indium zinc oxide, is a transparent conductive oxide material. With its high transparency and conductivity, it can be used as part of an electrode or as a transparent conductive layer to collect and transmit charge while ensuring that sunlight can penetrate into the perovskite absorption layer, typically located at the top of the cell and in contact with the electron transport layer, to collect and transmit charge. Its transparency also helps improve the cell's light absorption efficiency.

[0044] In some embodiments, the mass ratio of the first hole transport material to the second hole transport material is (1:1) to (1:5).

[0045] By rationally selecting the types and ratios of the first and second hole transport materials, the energy levels of the organic hole transport layer can be better matched with those of the perovskite absorber layer, reducing the barrier for hole transport from the perovskite absorber layer to the organic hole transport layer and improving hole extraction efficiency. Furthermore, the passivation of interfacial defects by the phosphate groups further reduces non-radiative recombination centers at the interface, inhibiting the non-radiative recombination process, thereby increasing the open-circuit voltage and fill factor of the battery, ultimately improving the overall photoelectric conversion efficiency of the tandem battery.

[0046] In some embodiments, the mass ratio of the first hole transport material to the second hole transport material is (1:2) to (1:4).

[0047] In some embodiments, the mass ratio of the first hole transport material to the second hole transport material is 1:3.

[0048] In some embodiments, the first hole transport material includes at least one of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, methoxy-modified [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, [4-(9H-carbazol-9-yl)phenyl]phosphonic acid, and methyl-modified [4-(9H-carbazol-9-yl)phenyl]phosphonic acid.

[0049] In some embodiments, the thickness of the organic hole transport layer is 1nm to 2nm. A thinner organic hole transport layer can significantly reduce the hole transport path, lowering the series resistance (Rs), thereby improving the fill factor (FF). If the thickness is too small (<1nm), it will not completely cover the substrate surface, resulting in local leakage. If the thickness is too large (>2nm), it will increase optical absorption loss (especially in the ultraviolet region) and reduce the short-circuit current density (Jsc). A thickness range of 1nm to 2nm can achieve a balance between interface passivation and optical transparency.

[0050] In some embodiments, the thickness of the organic hole transport layer is 1.2 nm to 1.8 nm.

[0051] In some embodiments, the thickness of the organic hole transport layer is 1.3 nm, 1.5 nm, or 1.7 nm.

[0052] In some embodiments, the thickness of the perovskite absorber layer is 500 nm to 650 nm, balancing absorption and carrier collection.

[0053] In some embodiments, the thickness of the perovskite absorber layer is 520 nm to 630 nm.

[0054] In some embodiments, the thickness of the perovskite absorber layer is 530 nm, 600 nm, or 620 nm.

[0055] The perovskite cell provided in the embodiments of the present application comprises a conductive substrate, an inorganic hole transport layer, an organic hole transport layer, a perovskite absorption layer, an electron transport layer, and electrodes arranged in sequence in a preset direction. The organic hole transport layer comprises a first hole transport material and a second hole transport material. The provision of the organic hole transport layer can effectively passivate the interface defects between the hole transport layer and the perovskite absorption layer, thereby better matching the energy levels between the HTL and the PVK, increasing the carrier extraction rate, thereby reducing non-radiative recombination, improving the overall cell parameters, and enhancing the photoelectric conversion efficiency of the perovskite cell.

[0056] Accordingly, the present invention also provides a method for preparing a perovskite battery, which can be used to prepare the perovskite battery provided in the above embodiment. The following describes in detail the method for preparing the perovskite battery provided in the embodiment of the present invention. It should be noted that the description of the perovskite battery in the above embodiment is also applicable to the following embodiment.

[0057] The preparation method of the perovskite battery includes: providing a conductive substrate, and sequentially forming an inorganic hole transport layer, an organic hole transport layer, a perovskite absorption layer, an electron transport layer and an electrode on the conductive substrate in a preset direction.

[0058] Figure 2 Schematic diagram of the preparation process of the organic hole transport layer in the preparation method of the perovskite battery provided in the embodiment of the present application.

[0059] refer to Figure 2 , the steps for preparing the organic hole transport layer include:

[0060] Step 100: Prepare a mixed solution containing a first hole transport material and a second hole transport material, wherein the first hole transport material is a carbazole-based hole transport material having a phosphate group, and the second hole transport material is (2-(pyrene-1-yl)ethyl)phosphonic acid.

[0061] Step 200: coating the mixed solution on the surface of the inorganic hole transport layer, and performing a first annealing treatment to form an organic hole transport layer.

[0062] Step 300: coating a perovskite precursor solution on the surface of the organic hole transport layer, and performing a second annealing treatment to form a perovskite absorption layer.

[0063] Step 400: Use an evaporator to deposit a 15nm C60 thin film on the perovskite absorption layer, and then use an ALD device to deposit SnO2 to prepare an electron transport layer.

[0064] Step 500: Depositing a TCO layer on the electron transport layer by magnetron sputtering to obtain a TCO layer.

[0065] Step 600: Evaporate a metal electrode on the TCO layer to prepare an electrode.

[0066] In some embodiments, step 100 further includes: mixing a first hole transport material and a first solvent to prepare a first solution, wherein the first hole transport material in the first solution has a first concentration, and the first concentration is 0.6 g / L-1.5 g / L, wherein the first hole transport material includes at least one of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, methoxy-modified [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, [4-(9H-carbazol-9-yl)phenyl]phosphonic acid, and methyl-modified [4-(9H-carbazol-9-yl)phenyl]phosphonic acid; mixing a second hole transport material and a second solvent to prepare a second solution, wherein the second hole transport material includes (2-(pyrene-1-yl)ethyl)phosphonic acid, and the second hole transport material in the second solution has a second concentration, and the second concentration is 0.6 g / L-1.5 g / L; mixing the first solution and the second solution in a volume ratio of (1:1) to (1:5) to obtain a mixed solution.

[0067] In some embodiments, the first concentration is the same as the second concentration. When the first concentration is the same as the second concentration and the first solution and the second solution are mixed at a specific volume ratio of (1:1) to (1:5), it helps to achieve a more uniform distribution of the two hole transport materials in the mixed solution. During the film formation process such as spin coating, this uniformly distributed solution can form a more uniform organic hole transport layer, making the anchoring effect more consistent across the entire substrate surface, avoiding local anchoring effect differences caused by uneven material distribution. Uniform anchoring helps reduce interface defects, thereby improving the stability of the overall anchoring performance, enhancing the bonding force between the organic hole transport layer and the conductive substrate, and forming a more stable and uniform organic hole transport layer. Such concentration and ratio settings also take into account the feasibility of the actual preparation process, which is beneficial to the stability and repeatability of the process.

[0068] In some embodiments, the first concentration and the second concentration are both 0.7 g / L-1.4 g / L, and the volume ratio of the first solution to the second solution in the mixed solution is (1:2) to (1:4).

[0069] In some embodiments, the first concentration and the second concentration may both be 0.8 g / L and 1.0 g / L, and the volume ratio of the first solution to the second solution in the mixed solution may be 1:3.

[0070] In some embodiments, the first solvent and the second solvent are each independently selected from at least one of ethanol and isopropyl alcohol, which have good solubility with the first hole transport material and the second hole transport material.

[0071] In some embodiments, the process parameters of the first annealing treatment include: an annealing temperature of 100°C to 140°C, and an annealing time of 8 minutes to 15 minutes, which can completely dry the organic hole transport layer. Within this temperature range, the molecules in the first hole transport material and the second hole transport material obtain sufficient energy to move and interact more fully, and the reaction between the phosphate groups and the metal sites of the conductive substrate is more active, which helps to form stronger chemical bonds, thereby enhancing the anchoring effect. The appropriate annealing temperature can promote a more orderly arrangement of molecules in the organic hole transport layer, forming a denser and more uniform film structure. This structural optimization helps to reduce defects and pores inside the film, making the contact between the organic hole transport layer and the substrate closer, and further improving the anchoring effect.

[0072] In some embodiments, step 200 further includes: coating the mixed solution by a spin coating method, wherein the rotation speed of the spin coating method is 4000 rpm to 5000 rpm and the duration is 20 seconds to 30 seconds, so that the mixed solution can be evenly coated on the inorganic hole transport layer.

[0073] The spread and film formation of the mixed solution on the inorganic hole transport layer can be effectively controlled within a rotational speed range of 4000 to 5000 rpm. The appropriate rotational speed allows the mixed solution to be evenly distributed across the substrate surface, forming a film of uniform thickness. This uniform film thickness helps ensure consistent distribution of the two hole transport materials in the organic hole transport layer across the substrate surface, allowing the phosphate groups to fully contact and react with the active sites on the substrate surface, thereby enhancing the overall anchoring effect.

[0074] In some embodiments, step 200 further includes: an annealing temperature of 110° C. to 130° C., an annealing time of 9 min to 12 min, a spin coating speed of 4200 rpm to 4500 rpm, and a time of 22 seconds to 27 seconds.

[0075] In some embodiments, step 300 also includes: coating the perovskite precursor solution using a spin coating method, and the spin coating method has a rotation speed of 3000rpm to 5000rpm and a duration of 20 seconds to 30 seconds, so that the perovskite precursor solution can be evenly coated on the organic hole transport layer; the process parameters of the second annealing treatment include: an annealing temperature of 90°C to 100°C, and an annealing time of 8min to 15min, so that the perovskite precursor can be crystallized.

[0076] At a rotation speed of 3000rpm to 5000rpm, the perovskite precursor solution can be evenly spread on the surface of the organic hole transport layer with appropriate centrifugal force to form a film of uniform thickness. The evenly coated perovskite precursor solution can form a good interface contact with the organic hole transport layer, which is conducive to the effective transmission of holes from the perovskite absorption layer to the organic hole transport layer, thereby improving the photoelectric conversion efficiency of the battery. The annealing time is 8min to 15min. This time range can ensure that the perovskite precursor is fully crystallized, while avoiding excessive annealing time that causes excessive crystal growth or other adverse reactions. The appropriate annealing time helps to obtain a perovskite absorption layer with moderate grain size and fewer defects, thereby improving the overall performance of the perovskite battery.

[0077] In some embodiments, step 300 further includes: a spin coating method with a rotation speed of 3200 rpm to 4500 rpm, a duration of 22 seconds to 27 seconds, an annealing temperature of 92° C. to 97° C., and an annealing time of 9 minutes to 12 minutes.

[0078] In some embodiments, the material of the TCO layer includes indium tin oxide (ITO), fluorine-doped tin oxide (FTO), and indium zinc oxide (IZO).

[0079] In some embodiments, the step of preparing the electrode includes: evaporating a metal electrode on the TCO layer.

[0080] Correspondingly, another aspect of an embodiment of the present application provides a stacked cell, comprising: a top cell, which is the perovskite cell in the above embodiment; and a crystalline silicon bottom cell, which is located on the side of the transparent conductive substrate of the perovskite cell away from the electrode.

[0081] Crystalline silicon bottom cells include any one of PERC cells (Passivated Emitter and Rear Cell, emitter and rear passivated cells), PERT cells (Passivated Emitter and Rear Totally-diffused cell, passivated emitter rear surface fully diffused cells), TOPCon cells (Tunnel Oxide Passivated Contact, tunnel oxide passivated contact cells), HIT / HJT cells (Heterojunction Technology, heterojunction cells) or BC cells (Back Contact, back contact cells).

[0082] Crystalline silicon bottom cells also include single crystal silicon solar cells, polycrystalline silicon solar cells, amorphous silicon solar cells or multi-compound solar cells. Multi-compound solar cells can specifically be cadmium sulfide solar cells, gallium arsenide solar cells, copper indium selenide solar cells or perovskite solar cells.

[0083] Correspondingly, another aspect of an embodiment of the present application provides a photovoltaic module, comprising: a plurality of stacked cells as in the above embodiments; a connecting component, the connecting component being used to connect adjacent stacked cells; an adhesive film, the adhesive film covering the surface of the stacked cells; and a cover plate, the cover plate being located on the surface of the adhesive film away from the stacked cells.

[0084] The connecting components include interconnecting ribbons and busbar ribbons. The interconnecting ribbons are tin-coated ribbons used to connect the laminated batteries, collect and transmit the current of the laminated batteries; the busbar ribbons are tin-coated ribbons used to connect the laminated battery strings and junction boxes, and transmit the current of the laminated battery strings.

[0085] The adhesive film may be an organic encapsulation film such as an ethylene-vinyl acetate copolymer (EVA) film, a polyethylene octene co-elastomer (POE) film or a polyvinyl butyral (PVB) film.

[0086] The cover plate can be a glass cover plate, a plastic cover plate, or other light-transmitting cover plate. In some embodiments, the surface of the cover plate facing the encapsulation layer can be a concave-convex surface, thereby increasing the utilization rate of the incident light.

[0087] In some embodiments, the method for preparing the above-mentioned perovskite battery includes:

[0088] (1) Prepare a mixed solution: weigh a first hole transport material, completely dissolve it in ethanol or isopropanol solution, add a magnet, stir on a stirring table overnight to dissolve it, and obtain a first solution. The first hole transport material includes at least one of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, methoxy-modified [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(9H-carbazole-9-yl)phenyl]phosphonic acid, and methyl-modified [4-(9H-carbazole-9-yl)phenyl]phosphonic acid. Weigh a second hole transport material (2-(pyrene-1-yl)ethyl)phosphonic acid, dissolve it in ethanol or isopropanol solution, stir it to fully dissolve it, and obtain a second solution. The first hole transport material has a first concentration in the first solution, and the second hole transport material has a second concentration in the second solution. The first concentration and the second concentration are the same, both being 0.6 g / L-1.5 g / L. Then, the first solution and the second solution are shaken at a volume ratio of (1:1) to (1:5) and mixed thoroughly to obtain a mixed solution.

[0089] (2) Preparation of organic hole transport layer: In a glove box, take an appropriate amount of the mixed solution and evenly add it to the inorganic hole transport layer, spin-coat it at 4000-5000 rpm for 20-30 seconds, and then anneal it at 100-140°C for 8-15 minutes. Then, cool the silicon wafer with the prepared organic hole transport layer to room temperature to obtain a conductive base layer / inorganic hole transport layer / organic hole transport layer substrate.

[0090] (3) Preparation of perovskite absorption layer: 50 μl of perovskite precursor solution was applied to the surface of the organic hole transport layer, spin-coated at 3000-5000 rpm for 20-30 seconds, and then annealed at 90-100°C for 8-15 minutes to prepare the perovskite absorption layer, thereby obtaining a conductive base layer / inorganic hole transport layer / organic hole transport layer / perovskite absorption layer substrate. The perovskite precursor solution was a mixture of CsI, PbI2, PbBr2, FAI, and MAI in DMF and DMSO in a certain molar ratio.

[0091] (4) Preparation of electron transport layer: The conductive base layer / inorganic hole transport layer / organic hole transport layer / perovskite absorption layer substrate obtained above was cooled to room temperature, a 15 nm C60 film was deposited thereon using an evaporator, and SnO2 was deposited using an ALD device to obtain a conductive base layer / inorganic hole transport layer / organic hole transport layer / perovskite absorption layer / electron transport layer substrate.

[0092] (5) Preparation of IZO film layer: magnetron sputtering is used to deposit the IZO film layer to obtain a conductive base layer / inorganic hole transport layer / organic hole transport layer / perovskite absorption layer / electron transport layer / IZO film substrate.

[0093] (6) Preparation of electrodes: Place the above substrate in a vacuum evaporation chamber and evaporate Ag (1000 nm) on the IZO film layer to obtain a perovskite cell.

[0094] Example 1:

[0095] The method for preparing the first perovskite cell is as follows:

[0096] (1) Prepare a mixed solution: weigh a first hole transport material, dissolve it completely in an ethanol solution, add a magnet, stir it on a stirring table overnight to dissolve it, and obtain a first solution. The first hole transport material is [2-(9H-carbazole-9-yl)ethyl]phosphonic acid. Weigh a second hole transport material (2-(pyrene-1-yl)ethyl)phosphonic acid, dissolve it in an isopropanol solution, stir it to fully dissolve it, and obtain a second solution. The first hole transport material in the first solution has a first concentration, and the second hole transport material in the second solution has a second concentration. The first concentration and the second concentration are the same, both 0.6 g / L. Then, the first solution and the second solution are shaken at a volume ratio of 1:1 and fully mixed to obtain a mixed solution.

[0097] (2) Preparation of organic hole transport layer: In a glove box, take an appropriate amount of the mixed solution and evenly add it to the inorganic hole transport layer, spin-coat it at 4000 rpm for 20 seconds, and then anneal it at 100°C for 8 minutes. Then, cool the silicon wafer with the prepared organic hole transport layer to room temperature to obtain a conductive base layer / inorganic hole transport layer / organic hole transport layer substrate.

[0098] (3) Preparation of perovskite absorption layer: 50 μl of perovskite precursor solution was applied to the surface of the organic hole transport layer, spin-coated at 3000 rpm for 20 seconds, and then annealed at 90°C for 8 minutes to prepare the perovskite absorption layer, thereby obtaining a conductive base layer / inorganic hole transport layer / organic hole transport layer / perovskite absorption layer substrate. The perovskite precursor solution was a mixture of CsI, PbI2, PbBr2, FAI, and MAI in DMF and DMSO at a certain molar ratio.

[0099] (4) Preparation of electron transport layer: The conductive base layer / inorganic hole transport layer / organic hole transport layer / perovskite absorption layer substrate obtained above was cooled to room temperature, a 15 nm C60 film was deposited thereon using an evaporator, and SnO2 was deposited using an ALD device to obtain a conductive base layer / inorganic hole transport layer / organic hole transport layer / perovskite absorption layer / electron transport layer substrate.

[0100] (5) Preparation of IZO film layer: magnetron sputtering is used to deposit the IZO film layer to obtain a conductive base layer / inorganic hole transport layer / organic hole transport layer / perovskite absorption layer / electron transport layer / IZO film substrate.

[0101] (6) Preparation of electrodes: The above substrate is placed in a vacuum evaporation chamber, and Ag (1000 nm) is evaporated on the IZO film layer to obtain the first perovskite cell.

[0102] Example 2:

[0103] The steps for preparing the second to sixteenth perovskite cells are basically the same as those in Example 1. The difference from Example 1 is that the preparation is performed according to the parameters in Table 1.

[0104] Table 1 Preparation parameters of the second to sixteenth perovskite cells

[0105]

[0106]

[0107]

[0108] Comparative Example 1:

[0109] A first comparative perovskite cell was prepared. The steps for preparing the first comparative perovskite cell were basically the same as those in Example 1, except that:

[0110] In step (1), the first hole transport material and the second hole transport material are both dissolved in ethanol or isopropanol solution. The first concentration and the second concentration are both 1.7 g / L. In the mixed solution, the volume ratio of the first solution to the second solution is 1:0.9.

[0111] In step (2), the film was spin-coated at 2500 rpm for 20 seconds and then annealed at 80° C. for 16 minutes.

[0112] In step (3), the film was spin-coated at 2500 rpm for 20 seconds and then annealed at 80° C. for 16 minutes.

[0113] Comparative Example 2:

[0114] A second comparative perovskite cell was prepared. The steps for preparing the second comparative perovskite cell were basically the same as those in Example 1, except that:

[0115] In step (1), there is only a single hole transport material, namely the first hole transport material. The first hole transport material is [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, and the first concentration is 0.6 g / L.

[0116] Adjust the solar simulator power to 100 mw / cm 2To simulate the AM 1.5G radiation standard, the device's current and voltage were read using a computer connected to a Keithley 2450 power meter. The performance of the first to sixteenth perovskite cells, as well as the first and second comparative perovskite cells, was measured using forward and reverse scanning. Detailed photovoltaic indices, including open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), and photovoltaic conversion efficiency (PCE), are shown in Table 2. Before measuring the current density-voltage curve, light intensity was calibrated using a Newport standard silicon cell 91150. The device was operated in forward and reverse scanning modes at a scan rate of 0.05 V / s.

[0117] Table 2 Battery performance test results

[0118]

[0119]

[0120] From the experimental data, compared with the first and second comparative perovskite cells, the performance of the first to sixteenth perovskite cells in the embodiment is significantly improved. The experimental results clearly show that the perovskite cells (the first to sixteenth perovskite cells) using a mixture of a carbazole-type hole material having a phosphate group and (2-(pyrene-1-yl)ethyl)phosphonic acid as an organic hole transport layer are significantly better than the cells using only a single hole transport material (the second comparative perovskite cell) and the cells with unreasonable parameter settings (the first comparative perovskite cell) in terms of Voc (open circuit voltage), Jsc (short circuit current density), FF (fill factor) and PCE (photovoltaic conversion efficiency). This shows that the mixed hole transport material can effectively improve the interface contact between the hole transport layer and the perovskite absorption layer, increase the carrier extraction rate, and thus improve the overall performance of the battery.

[0121] These results indicate that the combination of the first hole transport material and the second hole transport material in the embodiment of the present application reduces the energy loss at the interface by improving the interface contact between the Si substrate and the perovskite absorption layer, thereby effectively improving the open circuit voltage, short-circuit current density, fill factor and photoelectric conversion efficiency of the perovskite cell, demonstrating its effectiveness in improving the performance of the perovskite cell.

[0122] When the volume ratio of the first solution to the second solution is between 1:2 and 1:4, the battery performance reaches a relatively high level. In particular, the PCEs of the third and eleventh perovskite cells, both exceeding 30%, are the highest values in this group of cells. At this time, the volume ratio of the first solution to the second solution is 1:2. This indicates that within this ratio range, the synergistic effect of the two hole transport materials is most significant, effectively improving the interface contact between the hole transport layer and the perovskite absorber layer and increasing the carrier extraction rate.

[0123] The embodiment of the present application provides a perovskite cell, which includes a conductive substrate, an inorganic hole transport layer, an organic hole transport layer, a perovskite absorption layer, an electron transport layer and an electrode arranged in sequence in a preset direction. Among them, the organic hole transport layer includes a first hole transport material and a second hole transport material; the first hole transport material includes a carbazole hole material having a phosphate group; and the second hole transport material includes (2-(pyrene-1-yl)ethyl)phosphonic acid. The perovskite cell of the embodiment of the present application has a good bottom passivation effect, which can make the energy levels between HTL and PVK more matched, increase the carrier extraction rate, thereby reducing non-radiative recombination, improving the overall battery parameters, and solving the problem of poor performance of the perovskite cell. The embodiment of the present application also provides a preparation method for the above-mentioned perovskite cell, and a stacked cell using the above-mentioned perovskite cell. The raw material cost of the preparation method is low and suitable for industrial production. The stacked cell using the above-mentioned perovskite cell has good structural stability and can be stored outdoors for 1000 hours with a battery attenuation of less than 2%.

[0124] Those skilled in the art will appreciate that the above-described embodiments are specific examples for implementing the present disclosure, and that in actual applications, various changes in form and detail may be made thereto without departing from the spirit and scope of the present disclosure. Any person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be subject to the scope defined in the claims.

Claims

1. A perovskite battery, characterized in that: include: A conductive substrate, an inorganic hole transport layer, an organic hole transport layer, a perovskite absorption layer, an electron transport layer and an electrode are sequentially arranged in a preset direction, wherein the organic hole transport layer includes a first hole transport material and a second hole transport material; The first hole transport material includes a carbazole-based hole transport material having a phosphate group; The second hole transport material includes (2-(pyrene-1-yl)ethyl)phosphonic acid.

2. The perovskite battery according to claim 1, characterized in that The mass ratio of the first hole transport material to the second hole transport material is (1:1) to (1:5), and the first hole transport material includes at least one of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, methoxy-modified [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(9H-carbazole-9-yl)phenyl]phosphonic acid, and methyl-modified [4-(9H-carbazole-9-yl)phenyl]phosphonic acid.

3. The perovskite battery according to any one of claims 1 to 2, characterized in that: The thickness of the organic hole transport layer is 1 nm to 2 nm, and the thickness of the perovskite absorption layer is 500 nm to 650 nm.

4. A method for preparing a perovskite battery, characterized in that: include: A conductive substrate is provided, and an inorganic hole transport layer, an organic hole transport layer, a perovskite absorption layer, an electron transport layer, and an electrode are sequentially formed on the conductive substrate in a preset direction; wherein the preparation step of the organic hole transport layer comprises: preparing a mixed solution comprising a first hole transport material and a second hole transport material, wherein the first hole transport material is a carbazole-based hole transport material having a phosphate group, and the second hole transport material is (2-(pyrene-1-yl)ethyl)phosphonic acid; Applying the mixed solution on the surface of the inorganic hole transport layer and forming the organic hole transport layer after a first annealing treatment; A perovskite precursor solution is coated on the surface of the organic hole transport layer, and the perovskite absorption layer is formed through a second annealing treatment.

5. The method for preparing a perovskite battery according to claim 4, wherein: The steps of preparing the mixed solution include: Mixing the first hole transport material and a first solvent to prepare a first solution, wherein the first hole transport material in the first solution has a first concentration, and the first concentration is 0.6 g / L-1.5 g / L, wherein the first hole transport material includes at least one of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, methoxy-modified [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, [4-(9H-carbazol-9-yl)phenyl]phosphonic acid, and methyl-modified [4-(9H-carbazol-9-yl)phenyl]phosphonic acid; mixing the second hole transport material and a second solvent to prepare a second solution, wherein the second hole transport material includes (2-(pyrene-1-yl)ethyl)phosphonic acid, and the second hole transport material in the second solution has a second concentration, and the second concentration is 0.6 g / L-1.5 g / L; The first solution and the second solution are mixed in a volume ratio of (1:1) to (1:5) to obtain the mixed solution.

6. The method for preparing a perovskite battery according to claim 5, wherein: The first concentration is the same as the second concentration, and the first solvent and the second solvent are each independently selected from at least one of ethanol and isopropanol.

7. The method for preparing a perovskite battery according to any one of claims 4 to 6, characterized in that: The process parameters of the first annealing treatment include: an annealing temperature of 100° C. to 140° C., and an annealing time of 8 min to 15 min.

8. The method for preparing a perovskite battery according to any one of claims 4 to 6, characterized in that: The mixed solution is coated on the surface of the inorganic hole transport layer, comprising: coating the mixed solution by a spin coating method, wherein the rotation speed of the spin coating method is 4000 rpm to 5000 rpm and the duration is 20 seconds to 30 seconds.

9. The method for preparing a perovskite battery according to any one of claims 4 to 6, characterized in that: Coating a perovskite precursor solution on the surface of the organic hole transport layer comprises: The perovskite precursor solution is coated by a spin coating method, wherein the rotation speed of the spin coating method is 3000 rpm to 5000 rpm and the duration is 20 seconds to 30 seconds; The process parameters of the second annealing treatment include: an annealing temperature of 90° C. to 100° C., and an annealing time of 8 min to 15 min.

10. A stacked battery, characterized in that: include: A top cell, wherein the top cell is a perovskite cell according to any one of claims 1 to 9; A crystalline silicon bottom cell is located on a side of the transparent conductive substrate of the perovskite cell away from the electrode.

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