Bionic perovskite silicon nanoparticle photovoltaic cell and preparation method thereof

Abstract

The present application relates to the technical field of photovoltaic cells, and particularly relates to a kind of bionic perovskite silicon nanoparticle photovoltaic cell and preparation method thereof, including transparent conductive substrate, electron transport layer, nanometer silicon anti-reflection layer, perovskite / nanometer silicon composite light absorption layer, transition layer, nanometer silicon modified transport layer, hole transport layer and metal electrode from bottom to top are stacked in turn.By constructing four-layer bionic structure, nanometer silicon anti-reflection layer reduces reflection and blocks ultraviolet light, nanometer silicon and perovskite in composite absorption layer are complementary to realize 4001200nm full coverage absorption, transition layer optimizes energy level matching, and modified transport layer enhances charge transport.The present application solves the technical problems of existing cell spectrum absorption narrow, poor stability and high carrier recombination rate, significantly improves photoelectric conversion efficiency and extreme environmental adaptability, and is suitable for ground and space photovoltaic field.

Description

Technical Field

[0001] This invention relates to the technical field of photovoltaic cells, and in particular to a biomimetic perovskite silicon nanoparticle photovoltaic cell and its preparation method. Background Technology

[0002] Perovskite solar cells, as the core of third-generation photovoltaic technology, have achieved photoelectric conversion efficiency of up to 27% in recent years, approaching the level of traditional crystalline silicon cells, thanks to their advantages such as high light absorption coefficient, tunable bandgap, and low-cost fabrication. Furthermore, perovskite materials, due to their excellent radiation resistance and high specific power, are considered by both academia and industry as an important candidate technology for future spacecraft energy systems.

[0003] Existing technologies for improving the spectral response range and stability of perovskite solar cells mainly include: broadening spectral absorption by employing multi-absorber stacked structures, such as combining wide-bandgap perovskites with narrow-bandgap materials (e.g., LNMO, silicon) to form a double-absorber layer structure; introducing metal nanoparticles or patterns into the cell to enhance near-infrared light absorption using surface plasmon resonance effects; passivating defects and regulating the crystallization process through molecular engineering and additive strategies to improve device stability; and replacing organic transport layers with inorganic transport layer materials to improve radiation resistance. Regarding biomimetic approaches, existing research has proposed drawing inspiration from biological system design at the levels of chiral heterojunctions and multilayer surface microstructures to improve interfacial adhesion and mechanical durability.

[0004] However, existing perovskite solar cells still suffer from technical problems such as narrow spectral absorption range, poor stability in extreme environments, and high carrier recombination rate. Summary of the Invention

[0005] The purpose of this invention is to provide a biomimetic perovskite silicon nanoparticle photovoltaic cell and its preparation method, so as to solve the technical problems of perovskite cells in the prior art, such as narrow spectral absorption range, poor stability in extreme environments and high carrier recombination rate.

[0006] In a first aspect, the present invention provides a biomimetic perovskite silicon nanoparticle photovoltaic cell, comprising, from bottom to top, layers stacked as follows: Transparent conductive substrate; An electron transport layer is located on the upper surface of the transparent conductive substrate; The nano-silicon antireflective layer, located on the upper surface of the electron transport layer, is composed of nano-silicon particles with polar functional groups modified on their surface. A perovskite / nano-silicon composite light-absorbing layer, located on the upper surface of the nano-silicon anti-reflection layer, is composed of a perovskite matrix and nano-silicon particles dispersed in the perovskite matrix; The transition layer, located on the upper surface of the perovskite / nano-silicon composite light-absorbing layer, is composed of a metal oxide material. A nano-silicon modified transport layer, located on the upper surface of the transition layer, is composed of surface-modified nano-silicon and metal oxide nanoparticles. Hole transport layer, located on the upper surface of the nano-silicon modified transport layer; A metal electrode is located on the upper surface of the hole transport layer.

[0007] Furthermore, the thickness of the nano-silicon antireflective layer is 30-150 nm, and it is composed of nano-silicon particles with a particle size of 20-100 nm. The surface of the nano-silicon particles is modified with one or more functional groups selected from amino, hydroxyl, carboxyl or thiol groups.

[0008] Furthermore, the thickness of the perovskite / nano-silicon composite light-absorbing layer is 200-800 nm, and the mass ratio of the nano-silicon particles to the perovskite matrix is ​​1:15-5:10.

[0009] Furthermore, the thickness of the transition layer is 5-50 nm, and the metal oxide material is one or more of Cr2O3, CuO, Mn3O4, TiO2, ZnO, NiO, In2O3, or MgO.

[0010] Furthermore, the thickness of the nano-silicon modified transport layer is 30-150 nm, and it is composed of surface-modified nano-silicon and metal oxide nanoparticles in a mass ratio of 1:1-1:5, wherein the surface-modified nano-silicon is modified with a silane coupling agent.

[0011] Furthermore, the transparent conductive substrate is ITO glass, FTO glass, or a flexible conductive substrate with a sheet resistance ≤20Ω / sq; The thickness of the electron transport layer is 10-80 nm, and the material is one or more of SnO2, TiO2 or ZnO; The hole transport layer has a thickness of 50-300 nm and is made of one or more of Spiro-OMeTAD, PTAA, P3HT, and CuI. The thickness of the metal electrode is 30-250 nm, and the material is one or more of Al, Au, Ag, and Cu.

[0012] Secondly, the present invention also provides a method for preparing a biomimetic perovskite silicon nanoparticle photovoltaic cell, which includes the following steps: Step 1: Clean the transparent conductive substrate; Step 2: Fabricate an electron transport layer on the cleaned transparent conductive substrate; Step 3: Disperse surface-functionalized nano-silicon particles in a solvent, coat them onto the surface of the electron transport layer, and anneal them to form a nano-silicon anti-reflection layer; Step 4: Mix the perovskite precursor and nano-silicon particles in a solvent, coat the mixture onto the surface of the nano-silicon antireflective layer, and anneal it to form a perovskite / nano-silicon composite light-absorbing layer. Step 5: Prepare a transition layer on the surface of the perovskite / nano-silicon composite light-absorbing layer; Step 6: Mix surface-modified nano-silicon with metal oxide nanoparticles in a solvent, coat the mixture onto the surface of the transition layer, and anneal it to form a nano-silicon modified transport layer. Step 7: Prepare a hole transport layer on the surface of the nano-silicon modified transport layer; Step 8: Fabricate a metal electrode on the surface of the hole transport layer.

[0013] Furthermore, the nano-silicon particles described in steps 3 and 4 are prepared by in-situ synthesis, including: dissolving a silicon source and a surface modifier in a polar organic solvent, adding a reducing agent, carrying out a stepwise temperature-controlled reaction under inert gas protection, and obtaining surface-functionalized nano-silicon particles after centrifugation, washing, and drying.

[0014] Furthermore, the coating process described in steps 3, 4, and 6 is a spin coating, blade coating, spray coating, dip coating, inkjet printing, or screen printing method, with an annealing temperature of 80-250℃ and an annealing time of 5-60 minutes.

[0015] Furthermore, it also includes step 9: annealing the battery in an inert gas atmosphere, or preparing an encapsulation layer on the battery surface.

[0016] Compared with existing technologies, the biomimetic perovskite-silicon nanoparticle photovoltaic cell provided by this invention includes, from bottom to top, a transparent conductive substrate, an electron transport layer, a nano-silicon antireflective layer, a perovskite / nano-silicon composite light absorption layer, a transition layer, a nano-silicon modified transport layer, a hole transport layer, and a metal electrode. The electron transport layer is located on the upper surface of the transparent conductive substrate; the nano-silicon antireflective layer is located on the upper surface of the electron transport layer and is composed of nano-silicon particles with surface-modified polar functional groups; the perovskite / nano-silicon composite light absorption layer is located on the upper surface of the nano-silicon antireflective layer and is composed of a perovskite matrix and nano-silicon particles dispersed in the perovskite matrix; the transition layer is located on the upper surface of the perovskite / nano-silicon composite light absorption layer and is composed of a metal oxide material; the nano-silicon modified transport layer is located on the upper surface of the transition layer and is composed of surface-modified nano-silicon and metal oxide nanoparticles; the hole transport layer is located on the upper surface of the nano-silicon modified transport layer; and the metal electrode is located on the upper surface of the hole transport layer. By constructing a "nano-silicon antireflective layer-perovskite / nano-silicon composite light absorption layer," the photovoltaic cell achieves its purpose. The four-layer biomimetic structure of "absorption layer-transition layer-nanosilicon-modified transport layer" solves the technical problems of narrow spectral absorption range, poor stability in extreme environments, and high carrier recombination rate of existing perovskite solar cells. First, the nano-silicon anti-reflection layer with polar functional groups on its surface can effectively reduce surface light reflection and block strong ultraviolet radiation. At the same time, the nano-silicon particles dispersed in the perovskite / nanosilicon composite light absorption layer form spectral complementarity with the perovskite matrix, achieving full coverage absorption of the 400-1200nm solar spectrum, significantly improving the utilization of ultraviolet and near-infrared light. Firstly, the metal oxide transition layer optimizes energy level matching. Combined with the composite design of surface-modified nano-silicon and metal oxide nanoparticles in the nano-silicon modified transport layer, it synergistically reduces the interfacial carrier recombination rate and improves charge transport efficiency. Secondly, the multilayer biomimetic structure enhances the stability of the battery under extreme environments (such as strong ultraviolet radiation, wide-temperature cycling, and high-energy particle bombardment) through the chemical bonding of nano-silicon and the radiation resistance of metal oxides, providing a feasible technical solution for the application of perovskite batteries in fields such as space photovoltaics. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of the biomimetic perovskite silicon nanoparticle photovoltaic cell provided in an embodiment of the present invention. Figure 2This is an overall process flow diagram of the biomimetic perovskite silicon nanoparticle photovoltaic cell preparation method provided in the embodiments of the present invention.

[0019] Figure label: 100. Transparent conductive substrate; 200. Electron transport layer; 300. Nano-silicon anti-reflective layer; 400. Perovskite / nano-silicon composite light absorption layer; 500. Transition layer; 600. Nano-silicon modified transport layer; 700. Hole transport layer; 800. Metal electrode. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0022] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0023] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. These terms are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0024] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0025] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0027] Example 1 This invention provides a biomimetic perovskite silicon nanoparticle photovoltaic cell. Figure 1 This is a schematic diagram of the overall structure of the biomimetic perovskite silicon nanoparticle photovoltaic cell provided in an embodiment of the present invention. Figure 1 As shown, the battery comprises, from bottom to top, the following layers stacked sequentially: a transparent conductive substrate 100, an electron transport layer 200, a nano-silicon anti-reflection layer 300, a perovskite / nano-silicon composite light absorption layer 400, a transition layer 500, a nano-silicon modified transport layer 600, a hole transport layer 700, and a metal electrode 800.

[0028] Specifically, the transparent conductive substrate 100 serves as both the substrate and one of the electrodes of the battery. It is preferably ITO glass, FTO glass, or a flexible conductive substrate (such as PET-ITO) with a sheet resistance ≤20 Ω / sq to ensure good charge collection capability. The application of a flexible substrate can reduce the weight of the battery and make it adaptable to curved surface mounting requirements, such as for use on spacecraft surfaces or wearable devices.

[0029] An electron transport layer 200 is located on the upper surface of the transparent conductive substrate 100. Its main function is to extract photogenerated electrons from the perovskite / nano-silicon composite light-absorbing layer 400 and transport them to the transparent conductive substrate 100. The electron transport layer 200 is preferably made of one or more composite materials selected from SnO2, TiO2, or ZnO, with a thickness controlled between 10-80 nm. These metal oxide semiconductors have suitable energy level positions and high electron mobility, enabling them to form good energy level matching with the perovskite material, effectively extracting electrons and blocking holes.

[0030] The nano-silicon antireflective layer 300 is located on the upper surface of the electron transport layer 200, mimicking the light-gathering function of plant epidermis. It is composed of nano-silicon particles with polar functional groups modified on their surface. The particle size of these nano-silicon particles is preferably 20-100 nm, the overall thickness of the antireflective layer 300 is 30-150 nm, and the refractive index is between 1.7 and 2.3. By modifying the surface of the nano-silicon particles with polar functional groups such as amino (-NH2), hydroxyl (-OH), carboxyl (-COOH), or thiol (-SH), it can not only maintain long-term stable dispersion (≥6 months) in polar organic solvents such as DMF and DMSO, facilitating subsequent solution processing, but also enhance the interfacial bonding with adjacent layers. This layer effectively reduces the reflection loss of incident light on the battery surface by forming a refractive index gradient; at the same time, the nano-silicon material itself has a strong scattering and absorption capacity for ultraviolet light, which can block most of the high-energy ultraviolet radiation, thereby protecting the underlying perovskite light-absorbing layer from ultraviolet damage.

[0031] The perovskite / nano-silicon composite light-absorbing layer 400, located on the upper surface of the nano-silicon anti-reflection layer 300, is the core layer for achieving high-efficiency light absorption in the battery, mimicking the synergistic absorption mechanism of plant palisade tissue and chlorophyll. This layer is composed of a perovskite matrix and nano-silicon particles uniformly dispersed within the perovskite matrix. Its total thickness is preferably 200-800 nm, and the mass ratio of nano-silicon particles to the perovskite matrix is ​​preferably 1:15-5:10. The general chemical formula of perovskite is ABX3, where the A-site can be MA. + FA + Cs + 、Rb + One or more combinations of these cations can optimize the stability and photoelectric properties of the material; the B site is Pb². + Sn² + Or a combination thereof; X is I - ,Br - Cl - One or more of these halogens can be used to precisely tune the band gap of the perovskite (e.g., to 1.4-1.8 eV) to achieve optimal matching with the solar spectrum. In this layer, the nano-silicon particles are mainly responsible for absorbing short-wave ultraviolet and long-wave near-infrared light, while the perovskite matrix efficiently absorbs visible light. The two form spectral complementarity, thus achieving full coverage absorption of the 400-1200 nm solar spectrum. More importantly, the nano-silicon particles and the perovskite matrix are tightly connected through chemical bonds such as Si-O-metallic bonds or Si-N-metallic bonds. This chemical bonding not only enhances the interfacial charge transfer efficiency (reaching ≥85%), but also effectively passivates perovskite defects, inhibits ion migration, thereby significantly reducing the carrier recombination rate (more than 50% lower than the pure perovskite system) and improving the structural stability of the material under extreme environments.

[0032] The transition layer 500, located on the upper surface of the perovskite / nano-silicon composite light-absorbing layer 400, is composed of a metal oxide material. Its thickness is preferably 5-50 nm. The core function of this layer is to optimize energy level matching, providing an energy level "bridge" between the composite light-absorbing layer 400 and the upper nano-silicon modified transport layer 600, reducing interfacial charge recombination caused by energy level mismatch. Available metal oxide materials include, but are not limited to, one or more of Cr2O3, CuO, Mn3O4, TiO2, ZnO, NiO, In2O3, or MgO. These inorganic metal oxides not only possess suitable energy level positions but also exhibit excellent resistance to high-energy particle bombardment, serving as a barrier to protect the light-absorbing layer from damage caused by high-energy particles in subsequent processes or the space environment.

[0033] A nano-silicon modified transport layer 600 is located on the upper surface of the transition layer 500, simulating the light scattering and vein transport functions of plant spongy tissue. This layer is composed of surface-modified nano-silicon and metal oxide nanoparticles, with a preferred thickness of 30-150 nm and a preferred mass ratio of 1:1-1:5. The surface-modified nano-silicon is modified with one or more silane coupling agents (such as APTMS, KH550, KH560, KH570), which improves the dispersibility of nano-silicon in solvents and optimizes its interfacial contact with metal oxide particles. The nano-silicon particles in the composite structure can enhance the light scattering of transmitted light and extend the optical path of light in the absorption layer; at the same time, this composite transport layer has good charge transport capabilities, and due to the intrinsic properties of inorganic materials, it can maintain stable transport performance over a wide temperature range of -150℃ to 120℃.

[0034] Hole transport layer 700 is located on the upper surface of nano-silicon modified transport layer 600 and is used for extracting and transporting holes. Its material is preferably one or more of Spiro-OMeTAD, PTAA, P3HT, and CuI, and its thickness is 50-300 nm.

[0035] The metal electrode 800 is located on the upper surface of the hole transport layer 700, serving as another electrode of the battery. Its material is preferably one or more of Al, Au, Ag, and Cu, with a thickness of 30-250 nm, and is prepared by methods such as physical vapor deposition to ensure good conductivity and stability.

[0036] In summary, this embodiment constructs a four-layer biomimetic light absorption and transmission module with clearly defined functions and synergistic effects by simulating the multi-level structure of plant leaves. The nano-silicon anti-reflection layer 300 reduces reflection and blocks ultraviolet light, the composite light absorption layer 400 achieves complementary spectral absorption and efficient charge separation, the transition layer 500 optimizes energy level matching, and the nano-silicon modified transmission layer 600 promotes charge transport and light scattering. The selection and design of materials and structures in each layer jointly solve the technical problems of narrow spectral absorption, poor stability, and high carrier recombination rate in the prior art, resulting in significant improvements in both photoelectric conversion efficiency (33-39% for small areas and 23-29% for large areas) and stability in extreme environments (e.g., efficiency >99% after double 85 aging and efficiency retention ≥95% after 1000h light aging).

[0037] Example 2 This invention provides a method for preparing a biomimetic perovskite silicon nanoparticle photovoltaic cell, which is used to prepare the biomimetic perovskite silicon nanoparticle photovoltaic cell as described in Example 1. Figure 2 This is a flowchart illustrating the overall process flow of the biomimetic perovskite silicon nanoparticle photovoltaic cell fabrication method provided in this embodiment of the invention. Figure 2 As shown, the method includes the following steps: Step 1: Pretreatment of transparent conductive substrate The transparent conductive substrate (such as ITO glass, FTO glass, or flexible conductive substrate) is cleaned. Specifically, the substrate can be ultrasonically cleaned sequentially with acetone, ethanol, and deionized water to remove organic contaminants and particles from the surface. Subsequently, the substrate surface can be hydrophilized and further cleaned by ultraviolet-ozone treatment or plasma treatment to improve the adhesion and film quality of subsequent films.

[0038] Step 2: Fabrication of the electron transport layer An electron transport layer is prepared on a cleaned transparent conductive substrate. A precursor solution of an electron transport material (such as SnO2, TiO2, or ZnO) is prepared with water or an alcohol solvent to a suitable concentration. The precursor solution is coated onto the substrate surface using a solution method (such as spin coating or blade coating), and then annealed at a suitable temperature (such as 80-250℃) for approximately 5-60 min to form a dense electron transport layer with a thickness of 10-80 nm.

[0039] Step 3: Preparation of Nano-Silicon Anti-Reflection Layer First, surface-functionalized silicon nanoparticles were prepared via in-situ synthesis. The specific steps are as follows: A silicon source (such as tetraethyl orthosilicate (TEOS) or methyltriethoxysilane (MTES)) and a surface modifier (such as aminosilane or hydroxysilane) were dissolved in a dehydrated polar organic solvent (such as DMF or DMSO). Under inert gas protection, a reducing agent (such as NaBH4) was added, and hydrolysis and reduction were carried out through a stepwise temperature-controlled reaction to achieve precise control of particle size. After the reaction, the nanoparticles were centrifuged, washed, and dried to obtain uniformly sized (CV≤10%) silicon nanoparticles with polar functional groups (such as amino and hydroxyl groups) on their surface. Their absolute Zeta potential was ≥25mV, ensuring long-term dispersion stability (≥6 months) in polar solvents. Then, the obtained surface-functionalized silicon nanoparticles were dispersed in a suitable solvent (such as DMF or ethanol) to obtain a stable slurry. The slurry is coated onto the surface of the electron transport layer using a solution method (such as spin coating) and annealed at 80-250℃ for 5-60 min to form a nano-silicon antireflective layer with a thickness of 30-150 nm.

[0040] Step 4: Preparation of perovskite / nano-silicon composite light-absorbing layer A perovskite precursor (such as FAPbI3, MAPbI3, or a mixture thereof, the band gap of which can be optimized to 1.4-1.8 eV by adjusting the composition, such as by mixing cations / halogens) is dissolved / dispersed in a mixed solvent (such as DMF / DMSO) with the surface-functionalized silicon nanoparticles prepared in step 3 at a certain mass ratio (such as 1:15-5:10) to obtain a composite slurry. To ensure uniform dispersion of the silicon nanoparticles, ultrasonic treatment can be performed. This composite slurry is then coated onto the surface of the silicon nanoparticle antireflective layer using a solution method (such as spin coating, at a speed of 1000-6000 r / min for 10-60 s), and annealed at 80-250℃ for 5-60 min to form a perovskite / silicon nanoparticle composite light-absorbing layer with a thickness of 200-800 nm. During this process, the functional groups (such as -NH2) on the surface of the silicon nanoparticles interact with the perovskite components to form Si-O / Pb or Si-N / Pb chemical bonds, achieving interfacial chemical bonding.

[0041] Step 5: Preparation of the transition layer A transition layer is prepared on the surface of a perovskite / silicon nanocomposite light-absorbing layer. Depending on the selected metal oxide material (e.g., TiO2, NiO), it can be prepared using solution methods (e.g., spin-coating of metal oxide nanoparticle dispersions or precursor sols), sol-gel methods, atomic layer deposition (ALD), or magnetron sputtering. By controlling the process parameters, a dense or nanoparticle-stacking transition layer with a thickness of 5-50 nm can be formed. ALD and magnetron sputtering are particularly suitable for preparing ultrathin transition layers with precise thickness and uniform coverage.

[0042] Step 6: Fabrication of Nano-Silicon Modified Transport Layer Surface-modified nano-silicon (e.g., post-modified nano-silicon with a functional group density ≥1.5 mmol / g by silane coupling agent KH550) and metal oxide nanoparticles (such as TiO2 and SnO2 nanoparticles) are mixed in a solvent (such as ethanol) at a mass ratio of 1:1 to 1:5 and ultrasonically dispersed to obtain a transport layer slurry. This slurry is then coated onto the surface of the transition layer using a solution method (such as spin coating) and annealed at 80-250℃ for 5-60 min to form a nano-silicon modified transport layer with a thickness of 30-150 nm.

[0043] Step 7: Preparation of the hole transport layer Hole transport layers are prepared on the surface of nano-silicon modified transport layers. Hole transport materials (such as Spiro-OMeTAD, PTAA) and their additives (such as Li-TFSI, TBP) are dissolved in organic solvents (such as chlorobenzene) and coated into films by solution methods (such as spin coating). Subsequently, oxidation treatment is usually performed in dry air (e.g., static oxidation for 24 hours) to enhance its hole transport capability, forming a hole transport layer with a thickness of 50-300 nm.

[0044] Step 8: Metal Electrode Preparation A metal electrode is fabricated on the surface of the hole transport layer. A metal electrode with a thickness of 30-250 nm is deposited under vacuum conditions by physical vapor deposition (such as thermal evaporation or magnetron sputtering). The material can be one of Al, Au, Ag, Cu or an alloy thereof.

[0045] Step 9: Post-processing (optional) To further improve battery stability, especially for applications in extreme environments such as space, post-processing steps can be performed. For example, the prepared battery can be annealed in an inert gas atmosphere (such as nitrogen) to eliminate internal stress or unreacted substances. Alternatively, a dense encapsulation layer (such as Al2O3, SiN) can be prepared on the battery surface, particularly above the metal electrodes, using atomic layer deposition (ALD) or other encapsulation techniques. x This is to isolate water and oxygen, block high-energy particle radiation, and improve the long-term reliability of the device.

[0046] By following the above steps, the following can be obtained: Figure 1 The diagram illustrates a high-performance and highly stable biomimetic perovskite-silicon nanoparticle photovoltaic cell. The fabrication method presented has a clear process route, and the solution method, annealing, and physical vapor deposition techniques used in each step are all mature processes in the photovoltaic field. It exhibits good compatibility with existing perovskite cell production lines and is easily scalable for mass production.

[0047] Using the preparation method of Example 2, by changing the mass ratio of nano-silicon to perovskite and testing the battery performance, the following table can be obtained:

[0048] Conclusion: When the mass ratio of nano-silicon to perovskite is 2:10, the battery exhibits the best overall performance, the highest photoelectric conversion efficiency, and the best stability.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A biomimetic perovskite silicon nanoparticle photovoltaic cell, characterized in that, Including those stacked from bottom to top: Transparent conductive substrate; An electron transport layer is located on the upper surface of the transparent conductive substrate; The nano-silicon antireflective layer, located on the upper surface of the electron transport layer, is composed of nano-silicon particles with polar functional groups modified on their surface. A perovskite / nano-silicon composite light-absorbing layer, located on the upper surface of the nano-silicon anti-reflection layer, is composed of a perovskite matrix and nano-silicon particles dispersed in the perovskite matrix; The transition layer, located on the upper surface of the perovskite / nano-silicon composite light-absorbing layer, is composed of a metal oxide material. A nano-silicon modified transport layer, located on the upper surface of the transition layer, is composed of surface-modified nano-silicon and metal oxide nanoparticles. Hole transport layer, located on the upper surface of the nano-silicon modified transport layer; A metal electrode is located on the upper surface of the hole transport layer.

2. The biomimetic perovskite silicon nanoparticle photovoltaic cell according to claim 1, characterized in that, The thickness of the nano-silicon antireflective layer is 30-150 nm, and it is composed of nano-silicon particles with a particle size of 20-100 nm. The surface of the nano-silicon particles is modified with one or more functional groups selected from amino, hydroxyl, carboxyl or thiol groups.

3. The biomimetic perovskite silicon nanoparticle photovoltaic cell according to claim 2, characterized in that, The thickness of the perovskite / nano-silicon composite light-absorbing layer is 200-800 nm, and the mass ratio of the nano-silicon particles to the perovskite matrix is ​​1:15-5:

10.

4. The biomimetic perovskite silicon nanoparticle photovoltaic cell according to any one of claims 1-3, characterized in that, The thickness of the transition layer is 5-50 nm, and the metal oxide material is one or more of Cr2O3, CuO, Mn3O4, TiO2, ZnO, NiO, In2O3 or MgO.

5. The biomimetic perovskite silicon nanoparticle photovoltaic cell according to any one of claims 1-3, characterized in that, The thickness of the nano-silicon modified transport layer is 30-150 nm, and it is composed of surface-modified nano-silicon and metal oxide nanoparticles in a mass ratio of 1:1-1:

5. The surface-modified nano-silicon is modified with a silane coupling agent.

6. The biomimetic perovskite silicon nanoparticle photovoltaic cell according to any one of claims 1-3, characterized in that, The transparent conductive substrate is ITO glass, FTO glass, or a flexible conductive substrate with a sheet resistance ≤20Ω / sq. The thickness of the electron transport layer is 10-80 nm, and the material is one or more of SnO2, TiO2 or ZnO; The hole transport layer has a thickness of 50-300 nm and is made of one or more of Spiro-OMeTAD, PTAA, P3HT, and CuI. The thickness of the metal electrode is 30-250 nm, and the material is one or more of Al, Au, Ag, and Cu.

7. A method for preparing a biomimetic perovskite silicon nanoparticle photovoltaic cell, used to prepare the biomimetic perovskite silicon nanoparticle photovoltaic cell as described in any one of claims 1-6, characterized in that, Includes the following steps: Step 1: Clean the transparent conductive substrate; Step 2: Fabricate an electron transport layer on the cleaned transparent conductive substrate; Step 3: Disperse surface-functionalized nano-silicon particles in a solvent, coat them onto the surface of the electron transport layer, and anneal them to form a nano-silicon anti-reflection layer; Step 4: Mix the perovskite precursor and nano-silicon particles in a solvent, coat the mixture onto the surface of the nano-silicon antireflective layer, and anneal it to form a perovskite / nano-silicon composite light-absorbing layer. Step 5: Prepare a transition layer on the surface of the perovskite / nano-silicon composite light-absorbing layer; Step 6: Mix surface-modified nano-silicon with metal oxide nanoparticles in a solvent, coat the mixture onto the surface of the transition layer, and anneal it to form a nano-silicon modified transport layer. Step 7: Prepare a hole transport layer on the surface of the nano-silicon modified transport layer; Step 8: Fabricate a metal electrode on the surface of the hole transport layer.

8. The method for preparing biomimetic perovskite silicon nanoparticle photovoltaic cells according to claim 7, characterized in that, The nano-silicon particles described in steps 3 and 4 are prepared by in-situ synthesis, which includes: dissolving a silicon source and a surface modifier in a polar organic solvent, adding a reducing agent, carrying out a stepwise temperature-controlled reaction under inert gas protection, and obtaining surface-functionalized nano-silicon particles after centrifugation, washing, and drying.

9. The method for preparing biomimetic perovskite silicon nanoparticle photovoltaic cells according to claim 7 or 8, characterized in that, The coating process described in steps 3, 4, and 6 is by spin coating, blade coating, spray coating, dip coating, inkjet printing, or screen printing. The annealing temperature is 80-250℃, and the annealing time is 5-60 minutes.

10. The method for preparing biomimetic perovskite silicon nanoparticle photovoltaic cells according to claim 7 or 8, characterized in that, Also includes; Step 9: Anneal the battery in an inert gas atmosphere, or prepare an encapsulation layer on the battery surface.

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