Flexible semitransparent photovoltaic cell structure with infrared light reflection function and preparation method and application thereof

Abstract

The invention provides a flexible semitransparent photovoltaic cell structure with an infrared light reflection function and a preparation method and application thereof. The flexible semitransparent photovoltaic cell structure is sequentially provided with a curved surface reflector, a substrate layer, a first transparent electrode and / or a first transmission layer, a light absorption layer, a second transmission layer and / or a second transparent electrode and a packaging layer from bottom to top, and other layers are attached to the surface of the curved surface reflector or directly prepared on the surface of the curved surface reflector. Wherein the first transmission layer is a hole transmission layer or an electron transmission layer, the second transmission layer is an electron transmission layer or a hole transmission layer, and the substrate layer is a flexible high-transmittance substrate or a flexible spectrum selective transflective layer. The flexible semitransparent photovoltaic cell structure with the infrared light reflection function can be applied to slot type and disc type photo-thermal power stations, the utilization rate of solar spectrum is improved, the cooperative utilization efficiency of photovoltaic power generation and photo-thermal utilization is remarkably improved, and the flexible semitransparent photovoltaic cell structure has wide application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic cells, and in particular to a flexible semi-transparent photovoltaic cell structure with infrared light reflection function, a preparation method and application thereof. Background Art

[0002] As the global demand for clean energy continues to grow, photovoltaic power generation and solar thermal power generation technologies, as key components of renewable energy, are receiving widespread attention. Traditional photovoltaic systems usually use visible light bands for photoelectric conversion, while the unused infrared bands cause heat loss. In addition, when photovoltaic systems are combined with solar thermal systems, it is often difficult to significantly improve system efficiency due to structural incompatibility. Especially in trough and parabolic reflector solar thermal systems, due to the curved surface characteristics of the reflector, it is difficult for traditional photovoltaic devices to fit the curved surface and maintain efficient electrical and thermal synergistic conversion performance.

[0003] The emergence of flexible semi-transparent photovoltaic cells provides a possible solution to this problem. This type of cell not only has a certain degree of mechanical flexibility and can fit the surface of reflectors with different curvatures, but can also optimize the utilization of the solar spectrum by designing a spectrally selective transflective layer. However, the existing flexible semi-transparent photovoltaic cell structure is still not well designed in terms of infrared reflection. It usually only focuses on the reflection or transmission of ultraviolet and visible light, and does not effectively reflect infrared light back to the photothermal system, resulting in thermal energy utilization that does not meet expectations.

[0004] Therefore, in order to achieve efficient and coordinated utilization of photoelectric and photothermal energy, a flexible semi-transparent photovoltaic cell structure with infrared light reflection function is urgently needed. This structure should not only have good surface adaptability, but also be able to effectively separate different bands in the solar spectrum, realize efficient photoelectric conversion of visible light and photothermal recovery of infrared light, so as to comprehensively improve the comprehensive utilization efficiency of solar energy.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The purpose of the present invention is to provide a flexible semi-transparent photovoltaic cell structure with infrared light reflection function and its preparation method and application, wherein the flexible semi-transparent photovoltaic cell structure significantly improves the synergistic utilization efficiency of photovoltaic power generation and photothermal utilization.

[0007] The flexible semi-transparent photovoltaic cell structure with infrared light reflection function of the present invention is provided with a curved reflector, a substrate layer, a first transparent electrode and / or a first transmission layer, a light absorption layer, a second transmission layer and / or a second transparent electrode, and an encapsulation layer in order from bottom to top; wherein:

[0008] The first transport layer is a hole transport layer, and the second transport layer is an electron transport layer; or, the first transport layer is an electron transport layer, and the second transport layer is a hole transport layer;

[0009] The substrate layer is a flexible high-transmittance substrate, which is attached to the surface of the curved reflector; or, the substrate layer is a flexible spectrally selective reflective layer, which is directly prepared on the surface of the curved reflector.

[0010] The curved reflector includes a curved substrate, and a high-reflectivity metal layer and a weather-resistant protective layer are sequentially arranged on the lower surface of the curved substrate; wherein the material of the high-reflectivity metal layer can be a high-reflectivity metal such as silver or aluminum, and the thickness of the high-reflectivity metal layer can be 20nm-500μm, preferably 50-500nm, for example, 100-200nm; the material of the weather-resistant protective layer can be a weather-resistant material such as aluminum oxide, polymer coating, SiO2, TiO2, and the thickness of the weather-resistant protective layer can be 10nm-500μm, preferably 30-300nm, for example, 80-100nm.

[0011] The flexible high-transmittance substrate is used to carry the photovoltaic layer, and has high light transmittance and mechanical flexibility; specifically, the material of the flexible high-transmittance substrate can be polyethylene terephthalate, polyimide, polyethylene naphthalate, etc.; the thickness of the flexible high-transmittance substrate can be 10-900μm, for example, 60μm.

[0012] The flexible spectrally selective transflective layer includes an infrared transmissive film layer arranged on a curved reflector, on which titanium dioxide layers and magnesium fluoride layers are alternately arranged; wherein the material of the infrared transmissive film layer may be silicon dioxide, silicon nitride, etc., the thickness of the infrared transmissive film layer may be 100-500nm, preferably 100-300nm, and the infrared transmissive film layer has good infrared light transmittance and mechanical durability; the thickness of the titanium dioxide layer is 30-300nm, and the thickness of the magnesium fluoride layer is 50-500nm; the total number of titanium dioxide layers and magnesium fluoride layers is 4-10 layers, and the total thickness is 300-800nm. The above-mentioned flexible spectrally selective transflective layer is reflective in the ultraviolet and visible light bands, and the reflectivity can reach more than 90%.

[0013] The first transparent electrode is mainly used to collect carriers in the flexible semi-transparent photovoltaic cell while ensuring high light transmittance. Specifically, the material of the first transparent electrode can be indium tin oxide, zinc aluminum oxide, fluorine-doped tin oxide, etc.; the thickness of the first transparent electrode can be 50-150nm, for example, 30-100nm.

[0014] The hole transport layer is mainly used to effectively transport holes generated by the light absorption layer and prevent reverse electron transport. Specifically, the material of the hole transport layer can be poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], nickel oxide, etc.; the thickness of the hole transport layer can be 10-50nm, preferably 20-40nm.

[0015] The electron transport layer is mainly used for electron conduction. Specifically, the material of the electron transport layer can be fullerene, tin oxide, [6,6]-phenyl-C 61 -methyl butyrate, nanocrystalline TiO2, etc.; the thickness of the electron transport layer can be 20-50nm.

[0016] The light absorption layer is the core component of the flexible semi-transparent photovoltaic cell, which is mainly responsible for converting photons into electron-hole pairs. Specifically, the light absorption layer can be a light absorption layer such as perovskite, quantum dots, organic materials, dye sensitization, etc.; the thickness of the light absorption layer can be 300-2000nm, for example, 400-500nm.

[0017] The second transparent electrode is mainly used to collect electrons and conduct current while maintaining light transmittance. Specifically, the material of the second transparent electrode can be indium tin oxide, zinc aluminum oxide, silver nanowires, graphene, etc.; the thickness of the second transparent electrode can be 30-200nm, for example, 30-80nm.

[0018] The encapsulation layer is mainly used to protect the flexible semi-transparent photovoltaic cell structure from the erosion of moisture and oxygen in the environment, thereby extending the life of the flexible semi-transparent photovoltaic cell structure. Specifically, the material of the encapsulation layer can be ethylene-vinyl acetate, polyvinylidene fluoride, butyl rubber, silicone, etc.; the thickness of the encapsulation layer can be 50-500μm, for example, 150-200μm.

[0019] The present invention also provides a method for preparing the above-mentioned flexible semi-transparent photovoltaic cell structure, comprising the following steps:

[0020] S1: Preparation of curved reflector;

[0021] S2: Prepare a flexible high-transmittance substrate, and prepare a first transparent electrode and / or a first transmission layer, a light absorption layer, a second transmission layer and / or a second transparent electrode, and an encapsulation layer in sequence on the flexible high-transmittance substrate, and then attach the flexible high-transmittance substrate to the surface of a curved reflector; or, prepare a flexible spectrally selective reflective layer, a first transparent electrode and / or a first transmission layer, a light absorption layer, a second transmission layer and / or a second transparent electrode, and an encapsulation layer in sequence on the surface of the curved reflector; or, prepare a first transparent electrode and / or a first transmission layer, a light absorption layer, a second transmission layer and / or a second transparent electrode, and an encapsulation layer in sequence on the surface of the curved reflector.

[0022] The present invention can prepare an adhesive flexible semi-transparent photovoltaic cell structure with an infrared light reflection function by a post-attachment method, and can also prepare an integrated flexible semi-transparent photovoltaic cell structure with an infrared light reflection function by a direct preparation method.

[0023] When preparing the adhesive flexible semi-transparent photovoltaic cell structure by post-attachment, a flexible high-transmittance substrate is first prepared, and other layers are sequentially prepared on the flexible high-transmittance substrate, and then the flexible high-transmittance substrate is attached to the surface of the curved reflector by an adhesive layer or other attachment process. The flexible semi-transparent photovoltaic cell structure not only has good surface adaptability, but also allows part of the light to pass through, thereby realizing the dual utilization of different bands in the spectrum. The flexible semi-transparent photovoltaic cell absorbs visible light bands to generate electricity, while the unabsorbed infrared photons pass through the flexible semi-transparent photovoltaic cell and are reflected back to the thermal energy collection system by the curved reflector, realizing efficient synergy of photovoltaic and photothermal. The flexible semi-transparent photovoltaic cell structure can be flexibly applied to different curved reflectors, especially in combination with the solar collection system of trough, dish or parabolic reflectors, which improves the spectral utilization rate of the system; at the same time, the flexible semi-transparent photovoltaic cell structure can not only generate electricity efficiently, but also reflect long-wave photons through the flexible semi-transparent photovoltaic cell to the photothermal system, thereby increasing the utilization of thermal energy without losing electrical energy efficiency. The process is simple and easy, the adhesive can be cleaned, and it is suitable for later maintenance and component replacement, which enhances the operability and flexibility of the system.

[0024] When preparing an integrated flexible semi-transparent photovoltaic cell structure by direct preparation, a flexible spectrally selective transflective layer is first prepared on the upper surface of the curved reflector, and then other layers are sequentially prepared on the flexible spectrally selective transflective layer. The flexible spectrally selective transflective layer can spectrally select the incident sunlight, allowing infrared light to pass through the curved reflector and further be used for photothermal conversion, while ultraviolet light and visible light are reflected back to the flexible semi-transparent photovoltaic cell to improve the photoelectric conversion efficiency, thereby achieving efficient synergy of photovoltaic power generation and photothermal utilization.

[0025] Specifically, the method for preparing the curved reflector may include:

[0026] A) Fine polishing of the curved substrate;

[0027] B) uniformly depositing a silver or aluminum film on the lower surface of a finely polished curved substrate to form a high reflectivity metal layer;

[0028] C) depositing or spin-coating a polymer coating, aluminum oxide, SiO2 or TiO2 on the surface of the high reflectivity metal layer to form a weather-resistant protective layer.

[0029] In step B), a silver or aluminum film can be uniformly deposited on a finely polished curved substrate by vacuum evaporation or magnetron sputtering; in step C), SiO2 or TiO2 can be added to the surface of the high-reflectivity metal layer by chemical vapor deposition (CVD) or spin coating to form a weather-resistant protective layer to enhance its corrosion resistance and durability.

[0030] The preparation method of the flexible high-transmittance substrate may include: heating polyethylene terephthalate (PET), polyimide (PI) or polyethylene naphthalate (PEN) to a molten state and extruding it into a film by a melt extrusion process, and then stretching it to enhance its mechanical properties; the stretching may be performed by the following method:

[0031] 1) Preheating and stretching: The extruded film is first heated to a temperature close to the melting point (for example, the PET substrate can be heated to 70-90°C) to make its molecular chains in a moderately relaxed state; preheating and stretching helps to stretch uniformly, thereby improving the transparency and surface smoothness of the flexible and highly transparent substrate.

[0032] 2) Longitudinal stretching: The preheated and stretched film is stretched longitudinally (in the same direction as the extrusion direction) on a longitudinal stretching device to make the molecular chains more closely arranged; longitudinal stretching can significantly improve the mechanical strength of the film. The longitudinal stretching ratio is usually between 1.5 and 3 times and can be adjusted appropriately according to the material properties.

[0033] 3) Transverse stretching: The longitudinally stretched film is stretched in the transverse direction (perpendicular to the extrusion direction) on a transverse stretching device to increase its flexibility and dimensional stability; the transverse stretching ratio is generally 2-4 times, and the specific ratio depends on the substrate material and expected performance.

[0034] 4) Biaxial stretching: In some cases, in order to enhance the isotropic uniformity of the film, biaxial stretching can be selectively performed, that is, stretching in the longitudinal and transverse directions at the same time; this step is usually completed on a multi-axial stretching machine to ensure that the strength and flexibility of the substrate remain consistent in all directions.

[0035] 5) Annealing: After the above-mentioned multi-step stretching, the film will have residual internal stress; through annealing heating (for example, PET film is heat treated at 100-200°C), the molecular chains are readjusted to ensure the stability of the film size and reduce shrinkage or deformation during subsequent use.

[0036] After stretching, the film surface is treated with a plasma cleaning method to enhance its adhesion with subsequent coatings, thereby producing a flexible and highly transparent substrate that can adapt to curved reflectors.

[0037] The flexible spectrally selective reflective layer can effectively distinguish different bands in the solar spectrum, allowing infrared light to pass through and be transmitted to the curved reflector below for use in the photothermal system, by collecting and concentrating heat energy for power generation. The flexible spectrally selective reflective layer also has high reflectivity for ultraviolet and visible light, reflecting this part of light energy back to the flexible semi-transparent photovoltaic cell above for photoelectric conversion, ensuring efficient use of the solar spectrum, realizing the division of labor and cooperation between photovoltaic and photothermal systems, and significantly improving the overall conversion efficiency of solar energy.

[0038] The flexible semi-transparent photovoltaic cell structure allows a portion of the incident light to pass through its material structure, so as not to block the infrared light from penetrating downward to the flexible spectrally selective transflective layer for heat collection, while ensuring the efficiency of photovoltaic power generation. The flexibility of the flexible semi-transparent photovoltaic cell structure enables it to fit the complex shape of the curved reflector and adapt to the design requirements of different curvatures. It is particularly suitable for curved surface solar collection systems such as trough and dish solar thermal power stations. Through the reflection of ultraviolet and visible light, the flexible semi-transparent photovoltaic cell structure can efficiently utilize the energy of these spectral segments for electrical energy conversion while avoiding the spectral loss of the solar thermal system. Through the combination of the flexible spectrally selective transflective layer and the photovoltaic cell, the spectral separation technology and the coordinated utilization of photovoltaic and solar thermal are realized. The spectral reflection of ultraviolet and visible light and the transmission of infrared light enable the efficient separation and utilization of solar energy in the same system, optimizing the working efficiency of photovoltaic cells and solar thermal systems.

[0039] The preparation method of the flexible spectrally selective reflective layer may include: firstly depositing an infrared transmission film layer on the upper surface of the curved reflector by sputtering, chemical vapor deposition, physical vapor deposition, etc.; then, alternately depositing titanium dioxide layers and magnesium fluoride layers on the infrared transmission film layer to obtain a flexible spectrally selective reflective layer. By adopting a high-low refractive index alternating design, an interference film structure capable of reflecting ultraviolet light and visible light is formed, and the film layer is reflective in the ultraviolet and visible light bands, and the reflectivity can reach more than 90%.

[0040] The preparation method of the first transparent electrode may include: using magnetron sputtering to deposit indium tin oxide, zinc aluminum oxide or fluorine-doped tin oxide on the base layer. In order to ensure the uniformity of the first transparent electrode, a multi-target rotary sputtering process may be used; followed by heat treatment to enhance the conductivity and light transmittance of the film. The heat treatment temperature may be 100-300°C, and the heat treatment time may be 10-100min, for example, 10-30min.

[0041] The preparation method of the hole transport layer may include: depositing a hole transport material (for example, poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], nickel oxide, etc.) on a first transparent electrode by solution spin coating, and then annealing at 50-150° C. (for example, 80-100° C.) to remove the solvent and enhance the stability of the layer. The annealing time may be 0-60 min, for example, 10 min.

[0042] The preparation method of the light absorption layer may include: coating a perovskite precursor solution, a quantum dot solution, an organic solution, and a dye-sensitized solution on a hole transport layer / electron transport layer by a solution spin coating method. The preparation method of the perovskite light absorption layer is as follows: dropping a conventional perovskite precursor solution on a flexible substrate, and depositing a film layer by a two-step spin coating, an anti-solvent method, or a slit coating method; then, annealing the film layer at 60-180°C (e.g., 100-150°C) for 10-120min (e.g., 30min) to promote the formation and growth of perovskite crystals, and finally forming a flexible perovskite light absorption layer with high crystallinity and excellent light absorption performance.

[0043] The preparation method of the electron transport layer may include: spin coating or spray coating of the electron transport material (e.g., fullerene, tin oxide, [6,6]-phenyl-C 61 -methyl butyrate, nanocrystalline TiO2, etc.) are deposited on the light absorbing layer, and then annealed at 70-120°C to enhance the crystallinity and electron transport properties of the layer. The annealing time can be 10-60 minutes.

[0044] The preparation method of the second transparent electrode may include: using magnetron sputtering or thermal evaporation process to uniformly deposit indium tin oxide, zinc aluminum oxide, silver nanowires or graphene on the electron transport layer, and then performing heat treatment, the heat treatment temperature may be 80-150°C, for example, 100-150°C, and the heat treatment time may be 5-15min.

[0045] The preparation method of the encapsulation layer may include: using a lamination process to hot-press the encapsulation material in a vacuum or nitrogen atmosphere so that it is tightly wrapped around the outside of the entire photovoltaic cell structure to prevent environmental factors from damaging the photovoltaic cell structure; wherein the encapsulation material is ethylene-vinyl acetate, polyvinylidene fluoride, butyl rubber or silicone, the hot-pressing temperature is 100-200°C, for example, 120-130°C, and the hot-pressing time is 3-10 minutes.

[0046] The steps of attaching a flexible semi-transparent photovoltaic cell to a curved reflector include:

[0047] A) Surface cleaning: rinse the surface of the curved reflector with industrial ethanol, isopropanol, and deionized water in sequence, and then blow dry or dry with nitrogen;

[0048] B) Adhesive layer coating: evenly coating the surface of the curved reflector with a high-performance silicone adhesive, UV-curable adhesive, etc., with a coating thickness of 100-200 μm, and then drying to a semi-cured state to form an adhesive layer;

[0049] C) Positioning of the flexible semi-transparent photovoltaic cell: placing the prepared flexible semi-transparent photovoltaic cell on the adhesive layer for lamination; when laminating, laminating is performed gradually from one side to ensure that there are no bubbles between the flexible semi-transparent photovoltaic cell and the surface of the curved reflector. During the laminating process, a roller or other flexible tool may be used for light pressure to ensure that the flexible semi-transparent photovoltaic cell is tightly attached to the curved reflector and remains uniform;

[0050] D) Compression and curing treatment: Use a vacuum compression system, roller press, etc. to compress the entire system, and maintain uniform pressure to ensure that the bonding between the flexible translucent photovoltaic cell and the curved reflector is complete and firm; the compression treatment time can be 30 minutes to 2 hours to ensure sufficient adhesion; if a UV-curing adhesive is used, the cell surface can be irradiated with a UV light source to quickly cure the adhesive.

[0051] The present invention also provides the application of the above-mentioned flexible semi-transparent photovoltaic cell structure in trough-type solar thermal power stations and dish-type solar thermal power stations.

[0052] The flexible semi-transparent photovoltaic cell structure of the present invention has infrared light reflection characteristics and can be covered on the trough reflector to form a photovoltaic thermal coupling system. When sunlight irradiates the flexible semi-transparent photovoltaic cell structure with infrared light reflection function, ultraviolet light and visible light are absorbed by the flexible semi-transparent photovoltaic cell, and infrared light is reflected by the curved reflector to the heat collecting tube. In addition, the sun tracking axis can adjust the direction of the flexible semi-transparent photovoltaic cell structure to receive as much sunlight as possible. By integrating flexible semi-transparent photovoltaic cells on the trough reflector, the dual benefits of photovoltaic power generation and photothermal utilization are achieved, greatly improving the overall energy utilization efficiency of the trough solar thermal power station. In particular, the flexible semi-transparent photovoltaic cell structure adapts to the curved shape of the trough collector, simplifies the design and installation of the system, and can achieve full coverage of the curved reflector, thereby improving the heat collection efficiency. The photovoltaic cell works in conjunction with the photothermal system, which does not affect the thermal energy collection efficiency while also increasing the power output of the power station.

[0053] The flexible semi-transparent photovoltaic cell structure of the present invention can also be applied to the surface of a dish-type reflector to form a photovoltaic-thermal coupling system, which can not only generate electricity using the flexible semi-transparent photovoltaic cells, but also enhance the recycling of infrared light through its reflective characteristics. The collector in a dish-type solar thermal power station has a high complexity of curved surface design, and the flexibility of the flexible semi-transparent photovoltaic cell structure enables it to fit tightly to the surface of the curved reflector without making major changes to the existing structure of the power station. The flexible semi-transparent photovoltaic cell structure can be applied to the complex curved surface structure of the dish-type reflector, further enhancing the integration and design freedom of the photovoltaic-thermal coupling system. The semi-transparent characteristics of the flexible semi-transparent photovoltaic cell structure allow more solar radiation to pass through and be focused onto the receiver, improving the thermal energy utilization efficiency and power generation of the dish-type solar thermal power station, while maintaining the system's efficient thermal energy output, making it suitable for large-scale deployment in high-radiation areas.

[0054] The implementation of the present invention has at least the following advantages:

[0055] 1) Improvement of spectral selection and collaborative utilization efficiency:

[0056] The present invention attaches or prepares other layers on the surface of the curved reflector, thereby allowing infrared light to pass through and be used for photothermal conversion by the curved reflector, while reflecting ultraviolet light and visible light to the flexible semi-transparent photovoltaic cell for photoelectric conversion. By effectively separating different bands in sunlight, it is ensured that the photothermal system can fully utilize long-wavelength photons for thermal energy conversion, thereby improving the spectral utilization rate of the overall system; the above method overcomes the problem of incomplete utilization of solar energy by a single photovoltaic or photothermal system in the prior art, realizes dual energy utilization after spectral separation, and significantly improves the overall conversion efficiency of solar energy; in particular, the flexible spectrally selective transflective layer can reflect more than 95% of unused ultraviolet light and more than 90% of visible light to the flexible semi-transparent photovoltaic cell for photoelectric conversion, while the transmittance of infrared light is above 90%, ensuring the high efficiency of photovoltaic power generation.

[0057] 2) Synergistic effect of photovoltaic and solar thermal systems:

[0058] Compared with the independent operation of traditional photovoltaic and photothermal systems, the flexible semi-transparent photovoltaic cell structure of the present invention is a photovoltaic-photothermal coupling system, which realizes the synergistic effect of the two by integrating photovoltaic cells and photothermal systems on the same curved reflector; wherein, the thermal energy conversion efficiency of the photothermal system after integrating the photovoltaic cells is maintained at 60-80%, which is almost loss-free compared with a single photothermal system, while the photoelectric conversion efficiency of the photovoltaic cells is above 16%, and the photoelectric conversion efficiency of the photovoltaic-photothermal coupling system can reach above 28%.

[0059] 3) Flexible semi-transparent photovoltaic cell structure has strong adaptability:

[0060] The flexible semi-transparent photovoltaic cell structure of the present invention has excellent mechanical flexibility and can adapt to the complex shape of the curved reflector. It is particularly suitable for application scenarios with curved heat collection systems such as trough and dish-type solar thermal power stations. Compared with traditional rigid photovoltaic modules, the flexible semi-transparent photovoltaic cell structure of the present invention can achieve full coverage of the curved reflector, improving the spectral utilization of the system. In addition, the use of flexible materials simplifies the installation and maintenance process, can be replaced, and enhances the flexibility and reliability of the system, which is particularly suitable for large-scale deployment in high-radiation areas.

[0061] 4) Simple process, suitable for different application scenarios:

[0062] The preparation method of the present invention includes two process routes, namely, directly preparing other layers on the surface of the curved reflector, or attaching the base layer of the flexible semi-transparent photovoltaic cell to the surface of the curved reflector by an adhesive. The above two methods are respectively adapted to different application requirements and system installation scenarios, and have good process adaptability; whether it is a new system or the transformation and upgrading of an existing solar thermal power station, system integration can be achieved through simple process steps, reducing costs and improving operability.

[0063] 5) Enhanced durability and environmental adaptability:

[0064] After preparing a multi-layer structure on the surface of the photothermal curved reflector, dust, dirt and other environmental pollutants are effectively prevented from adhering to the photothermal reflector. This structure reduces the accumulation of pollution on the reflector surface during long-term operation, thereby reducing the frequency of subsequent cleaning and maintenance costs. This functional integrated design improves the service life and operating economy of the reflector system, providing a more sustainable solution for photothermal power applications.

[0065] In addition, the flexible semi-transparent photovoltaic cell structure of the present invention has good environmental adaptability through the protection of the encapsulation layer, and can resist the erosion of environmental factors such as water vapor and oxygen, and the barrier rate of water vapor reaches 99%, which prolongs the service life of the system and ensures the long-term durability of the battery in harsh environments. After 1000 hours of damp heat test (85℃ / 85% humidity), the performance attenuation of the flexible semi-transparent photovoltaic cell structure of the present invention is less than 10%.

[0066] In summary, the present invention significantly improves the efficiency of photovoltaic power generation and photothermal utilization through innovative spectral separation and coordinated utilization technology combined with the unique design of flexible semi-transparent photovoltaic cells. At the same time, it has advantages in system design, process implementation and environmental adaptability that cannot be achieved by existing technologies, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0068] Figure 1 This is a schematic structural diagram of the adhesive-type flexible semi-transparent photovoltaic cell structure of Example 1;

[0069] Figure 2 This is a schematic diagram of the internal structure of the adhesive flexible semi-transparent photovoltaic cell structure of Example 1;

[0070] Figure 3 This is a schematic diagram of the internal structure of the integrated flexible semi-transparent photovoltaic cell structure of Example 2;

[0071] Figure 4 This is a comparison chart of infrared light transmittance of flexible spectrally selective reflective layers with different structures;

[0072] Figure 5 This is a comparison chart of the ultraviolet and visible light reflectivity of flexible spectrally selective reflective layers with different structures;

[0073] Figure 6 This is a schematic diagram of the application of flexible semi-transparent photovoltaic cell structure in trough-type solar thermal power station;

[0074] Figure 7 Schematic diagram of the application of flexible semi-transparent photovoltaic cell structure in dish-type solar thermal power station.

[0075] Description of reference numerals:

[0076] 1: curved reflector; 2: flexible semi-transparent photovoltaic cell; 3: flexible high-transmittance substrate; 4: first transparent electrode; 5: hole transport layer; 6: light absorption layer; 7: electron transport layer; 8: second transparent electrode; 9: encapsulation layer; 10: flexible spectrally selective reflective layer; 11: thermal collector tube; 12: sunlight; 13: infrared light; 14: solar tracking axis. DETAILED DESCRIPTION

[0077] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0078] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form also includes the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this description, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0079] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0080] Example 1

[0081] Combination Figure 1 , Figure 2 As shown, this embodiment provides a method for preparing a pasted flexible semi-transparent photovoltaic cell structure with infrared light reflection function (referred to as photovoltaic thermal coupling system), comprising the following steps:

[0082] (1) Preparation of curved reflector 1:

[0083] The curved substrate is finely polished, and then a silver film is uniformly deposited on the lower surface of the finely polished curved substrate by a vacuum evaporation process to form a high-reflectivity metal layer with a thickness of 100 nm; then, SiO2 is deposited on the surface of the high-reflectivity metal layer by chemical vapor deposition to form a weather-resistant protective layer with a thickness of 80 nm, thereby obtaining a curved reflector 1.

[0084] (2) Preparation of flexible high-transparency substrate 3:

[0085] Polyethylene terephthalate (PET) is heated to a molten state through a melt extrusion process, and then extruded into a film, and subjected to multi-step stretching and annealing to enhance its mechanical properties; subsequently, the surface of the film is treated by a plasma cleaning method to obtain a flexible, highly transparent substrate 3 with a thickness of 60 μm that adapts to the curved reflector 1.

[0086] (3) Preparation of the first transparent electrode 4:

[0087] Indium tin oxide is deposited on the flexible high-transmittance substrate 3 by multi-target rotation sputtering, and then heat-treated at a temperature of 150° C. for 10 minutes to obtain a first transparent electrode 4 with a thickness of 30 nm.

[0088] (4) Preparation of hole transport layer 5:

[0089] Poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate is deposited on the first transparent electrode 4 by solution spin coating, and then annealed at 80° C. for 10 min to obtain a hole transport layer 5 with a thickness of 20 nm.

[0090] (5) Preparation of light absorbing layer 6:

[0091] The perovskite precursor solution is coated on the hole transport layer 5 by solution spin coating / slit coating, and a uniform perovskite film is formed by wet chemical deposition, followed by annealing at a temperature of 100°C for 30 minutes to obtain a 500nm, well-crystallized light absorption layer 6 (i.e., perovskite light absorption layer).

[0092] (6) Preparation of electron transport layer 7:

[0093] [6,6]-phenyl-C 61 -Methyl butyrate is deposited on the light absorbing layer 6, and then annealed at a temperature of 70°C for 10 minutes, thereby obtaining an electron transport layer 7 with a thickness of 20 nm.

[0094] (7) Preparation of the second transparent electrode 8:

[0095] Indium tin oxide is uniformly deposited on the electron transport layer 7 by magnetron sputtering, and then heat-treated at a temperature of 150° C. for 5 minutes to obtain a second transparent electrode 8 with a thickness of 30 nm.

[0096] (8) Preparation of encapsulation layer 9:

[0097] Ethylene-vinyl acetate was hot-pressed on the surface of the second transparent electrode 8 in a vacuum by a lamination process at 120° C. for 10 minutes to obtain an encapsulation layer 9 with a thickness of 200 μm.

[0098] The above-mentioned flexible high-transmittance substrate 3, first transparent electrode 4, hole transport layer 5, light absorption layer 6, electron transport layer 7, second transparent electrode 8 and encapsulation layer 9 constitute a flexible semi-transparent photovoltaic cell 2 (abbreviated as photovoltaic cell).

[0099] (9) Adhesion of flexible semi-transparent photovoltaic cell 2

[0100] Surface cleaning: Before the flexible semi-transparent photovoltaic cell 2 is attached to the curved reflector 1, the surface of the curved reflector 1 is first rinsed with industrial ethanol, isopropyl alcohol, and deionized water in sequence, and finally dried with nitrogen.

[0101] Adhesive layer coating: a high-performance silicone adhesive is evenly coated on the surface of the curved reflector 1 to form an adhesive layer, and the adhesive coating thickness is 150 microns; after coating, wait for a few minutes to allow the adhesive layer to dry slightly to a semi-cured state for subsequent pasting operations.

[0102] Positioning of the flexible semi-transparent photovoltaic cell 2: gradually place the prepared flexible semi-transparent photovoltaic cell 2 on the adhesive layer, and gradually bond them from one side to ensure that there are no bubbles between the flexible semi-transparent photovoltaic cell 2 and the surface of the curved reflector 1; during the bonding process, a roller or other flexible tools can be used for light pressure to ensure that the flexible semi-transparent photovoltaic cell 2 is tightly attached to the curved reflector 1 and remains even.

[0103] Compression and curing treatment: The entire system is compressed using a vacuum compression system, and uniform pressure is maintained for 45 minutes to ensure full adhesion, thereby obtaining a pasted flexible semi-transparent photovoltaic cell structure with infrared light reflection function.

[0104] After testing, the thermal energy conversion efficiency of the adhesive flexible semi-transparent photovoltaic cell structure of this embodiment is 60%, the photoelectric conversion efficiency of the photovoltaic cell is 16%, and the photoelectric conversion efficiency of the photovoltaic thermal coupling system is 28%; in addition, a 1000-hour wet heat test was carried out under 85°C and 85% humidity conditions; the results showed that the performance attenuation of the adhesive flexible semi-transparent photovoltaic cell structure of this embodiment was 10%.

[0105] Example 2

[0106] Combination Figure 3 As shown, this embodiment provides a method for preparing an integrated flexible semi-transparent photovoltaic cell structure with infrared light reflection function (referred to as photovoltaic thermal coupling system), comprising the following steps:

[0107] (1) Preparation of curved reflector 1:

[0108] The curved substrate is finely polished, and then an aluminum film is uniformly deposited on the finely polished curved substrate by a magnetron sputtering process to form a high-reflectivity metal layer with a thickness of 200 nm; then, TiO2 is deposited on the surface of the high-reflectivity metal layer by chemical vapor deposition to form a weather-resistant protective layer with a thickness of 100 nm, thereby obtaining a curved reflector 1.

[0109] (2) Preparation of flexible spectrally selective reflective layer 10 (three-layer selective reflective layer):

[0110] Silicon dioxide is deposited on the surface of the curved reflector 1 by physical vapor deposition to form an infrared transmission film layer with a thickness of 200 nm.

[0111] Titanium dioxide layers and magnesium fluoride layers are alternately deposited on the infrared transparent film layer, the thickness of each titanium dioxide layer is 50nm, the thickness of each magnesium fluoride layer is 100nm, and three layers of titanium dioxide layers and magnesium fluoride layers (collectively referred to as selective reflective layers) are deposited respectively to obtain a flexible spectral selective reflective layer 10 having three selective reflective layers.

[0112] Combination Figure 4 , Figure 5 As shown, the flexible spectrally selective reflective layer 10 has an ultraviolet light reflectivity of 95%, a visible light reflectivity of 90%, and an infrared light transmittance of 90%.

[0113] (3) Preparation of the first transparent electrode 4:

[0114] Zinc aluminum oxide is deposited on the flexible spectrally selective reflective layer 10 by multi-target rotation sputtering, and then heat treated at 150° C. for 30 minutes to obtain a first transparent electrode 4 with a thickness of 100 nm.

[0115] (4) Preparation of hole transport layer 5:

[0116] Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] was deposited on the first transparent electrode 4 by solution spin coating, and then annealed at a temperature of 100° C. for 10 min to obtain a hole transport layer 5 with a thickness of 40 nm.

[0117] (5) Preparation of light absorbing layer 6:

[0118] According to cesium iodide: methylammonium iodide: formamidine hydroiodide: lead iodide: lead bromide = 1:3:16:14:8, each raw material was dissolved in DMF and DMSO to prepare a perovskite precursor solution.

[0119] The perovskite precursor solution is coated on the hole transport layer 5 by solution spin coating, and a uniform perovskite film is formed by wet chemical deposition, followed by annealing at a temperature of 150° C. for 30 min, thereby obtaining a light absorption layer 6 with a thickness of 400 nm and good crystallization.

[0120] (6) Preparation of electron transport layer 7:

[0121] C60 and bathocuproin are deposited on the light absorbing layer 6 by thermal evaporation, so as to prepare an electron transporting layer 7 with a thickness of 50 nm.

[0122] (7) Preparation of the second transparent electrode 8:

[0123] Zinc aluminum oxide is uniformly deposited on the electron transport layer 7 by magnetron sputtering, and then heat treated at a temperature of 100° C. for 15 minutes to obtain a second transparent electrode 8 with a thickness of 80 nm.

[0124] (8) Preparation of encapsulation layer 9:

[0125] A lamination process is used to hot-press polyvinylidene fluoride on the surface of the second transparent electrode 8 at a temperature of 130°C in a nitrogen atmosphere for 10 minutes to obtain an encapsulation layer 9 with a thickness of 150 μm, that is, a flexible semi-transparent photovoltaic cell (abbreviated as photovoltaic cell) is obtained on the surface of the curved reflector 1.

[0126] After testing, the thermal energy conversion efficiency of the integrated flexible semi-transparent photovoltaic cell structure of this embodiment is 80%, the photoelectric conversion efficiency of the photovoltaic cell is 22%, and the photoelectric conversion efficiency of the photovoltaic thermal coupling system is 37%; in addition, a 1000-hour wet heat test was carried out under 85°C and 85% humidity conditions; the results showed that the performance attenuation of the integrated flexible semi-transparent photovoltaic cell structure of this embodiment was 5%.

[0127] Example 3

[0128] This embodiment provides a trough type solar thermal power station, which is provided with the flexible semi-transparent photovoltaic cell structure of embodiment 2.

[0129] Combination Figure 6 As shown, the photovoltaic cell of the flexible semi-transparent photovoltaic cell structure can be directly prepared on the trough reflector to form a photovoltaic thermal coupling system. When sunlight 12 irradiates the flexible semi-transparent photovoltaic cell 2, ultraviolet light and visible light are absorbed by the flexible semi-transparent photovoltaic cell 2, and infrared light 13 is reflected by the curved reflector 1 to the heat collecting tube 11. The sun tracking axis 14 can adjust the direction of the flexible semi-transparent photovoltaic cell structure to receive as much sunlight as possible. By integrating the flexible semi-transparent photovoltaic cell 2 on the trough reflector, the dual benefits of photovoltaic power generation and photothermal utilization are achieved, and the overall energy utilization efficiency of the trough solar thermal power station is greatly improved. In particular, the flexible semi-transparent photovoltaic cell structure adapts to the curved shape of the trough collector, simplifies the design and installation of the system, and can achieve full coverage of the curved reflector 1, thereby improving the heat collection efficiency. The photovoltaic cell works in conjunction with the photothermal system, which does not affect the thermal energy collection efficiency while also increasing the power output of the trough solar thermal power station.

[0130] Example 4

[0131] This embodiment provides a dish-type solar thermal power station, which is provided with the flexible semi-transparent photovoltaic cell structure of embodiment 2.

[0132] Combination Figure 7As shown, the photovoltaic cell of the flexible semi-transparent photovoltaic cell structure can be directly prepared on the dish reflector to form a photovoltaic thermal coupling system. When sunlight 12 irradiates the flexible semi-transparent photovoltaic cell 2, ultraviolet light and visible light are absorbed by the photovoltaic cell 2, and infrared light 13 is reflected by the curved reflector 1 to the heat collecting tube 11. The solar tracking axis 14 can adjust the direction of the flexible semi-transparent photovoltaic cell structure to receive as much sunlight 12 as possible. The collector in the dish-type solar thermal power station has a high complexity of curved surface design, and the flexibility of the flexible semi-transparent photovoltaic cell structure enables it to fit closely to the surface of the dish reflector without making major changes to the existing structure of the solar thermal power station. The flexible semi-transparent photovoltaic cell structure is applied to the complex curved surface of the dish reflector, further enhancing the integration and design freedom of the photovoltaic thermal coupling system. The semi-transparent characteristics of the flexible semi-transparent photovoltaic cell structure allow more solar radiation to pass through and focus on the receiver, which improves the thermal energy utilization efficiency and power generation of the dish-type solar thermal power station, while maintaining the efficient thermal energy output of the system, which is suitable for large-scale deployment in high-radiation areas.

[0133] Comparative Example 1: A selectively reflective layer

[0134] Except that only one selective reflective transmission layer is provided in the flexible spectrally selective reflective transmission layer, the rest is substantially the same as that of the second embodiment.

[0135] The preparation steps of the flexible spectrally selective reflective layer of this comparative example are as follows:

[0136] Silicon dioxide is deposited on the surface of the curved reflector 1 by physical vapor deposition to form an infrared transmission film layer with a thickness of 200 nm.

[0137] A titanium dioxide layer with a thickness of 50 nm and a magnesium fluoride layer with a thickness of 100 nm are sequentially deposited on the infrared transmission layer. Only one layer of the titanium dioxide layer and the magnesium fluoride layer is deposited to obtain a flexible spectrally selective reflection transmission layer 10 .

[0138] Combination Figure 4 , Figure 5 As shown, the ultraviolet light reflectivity of the flexible spectrally selective reflective layer of this control example is 85%, the visible light reflectivity is 80%, and the infrared light transmittance is 91%; the energy conversion efficiency of the flexible semi-transparent photovoltaic cell structure prepared using the flexible spectrally selective reflective layer is 70%, the photoelectric conversion efficiency of the photovoltaic cell is 19%, and the photoelectric conversion efficiency of the photovoltaic thermal coupling system is 32%.

[0139] Comparative Example 2: No selective reflective layer

[0140] Except that the flexible spectrally selective reflective layer is not provided with a selective reflective layer (that is, only an infrared transmitting film layer is provided), the rest is the same as that of the second embodiment.

[0141] The steps for preparing the flexible spectrally selective reflective layer of this comparative example are as follows:

[0142] Silicon dioxide is deposited on the surface of the curved reflector 1 by physical vapor deposition to form an infrared transmission film layer with a thickness of 200 nm. The infrared transmission film layer allows infrared light to pass through, but has limited selective reflection effects on ultraviolet light and visible light.

[0143] Combination Figure 4 , Figure 5 As shown, the ultraviolet light reflectivity of the flexible spectrally selective reflective layer of this control example is 50%, the visible light reflectivity is 40%, and the infrared light transmittance is 89%; the thermal energy conversion efficiency of the flexible semi-transparent photovoltaic cell structure prepared using the flexible spectrally selective reflective layer is 65%, the photoelectric conversion efficiency of the photovoltaic cell is 17%, and the photoelectric conversion efficiency of the photovoltaic thermal coupling system is 30%.

[0144] Comparative Example 3: Flexible semi-transparent photovoltaic cell alone

[0145] Except that the curved reflector and the flexible spectrally selective reflective layer are not provided, the rest is basically the same as that of Example 2.

[0146] The single flexible semi-transparent photovoltaic cell structure of this comparative example mainly includes: a curved substrate, a first transparent electrode, a hole transport layer, a perovskite light absorption layer, an electron transport layer, a second transparent electrode and an encapsulation layer.

[0147] After testing, the photoelectric conversion efficiency of the flexible semi-transparent photovoltaic cell structure alone in this control example is 16%, which is lower than the photoelectric efficiency in the photovoltaic-thermal coupling system, and lacks the reflection function of infrared light. Therefore, the thermal load of the light absorption layer is high, which is not conducive to the long-term stability of the battery.

[0148] Comparative Example 4: Single Trough / Dish CSP System

[0149] The single trough solar thermal power station or dish solar thermal power station system in this comparative example adopts an independent solar thermal collector structure, and does not have a photovoltaic cell structure; wherein the solar thermal system structure mainly includes: a high-reflectivity curved reflector (trough / dish reflector), a heat absorbing tube and a heat transfer medium.

[0150] The preparation steps of the single trough / dish CSP power station system in this comparative example are as follows:

[0151] 1) Installation of heat absorbing tubes: High-efficiency heat absorbing tubes are installed at the focusing position of the trough / dish CSP power station. The surface of the heat absorbing tubes is coated with a selective absorption coating to optimize the visible light absorption efficiency and reduce thermal radiation losses.

[0152] 2) Addition of heat transfer medium: The heat absorbing tube is filled with high-temperature heat transfer oil or molten salt materials to improve the efficiency of heat transfer and storage. The system converts light energy into heat energy through the photothermal conversion and storage device, and finally drives the power generation system.

[0153] The thermal energy conversion efficiency of the single trough type CSP power station in this comparative example is 50%, and the photoelectric conversion efficiency is 15%; the thermal energy conversion efficiency of the single dish type CSP power station is 60%, and the photoelectric conversion efficiency is 20%. Due to the lack of the photoelectric conversion capacity of the photovoltaic module, the single trough / dish type CSP power station system has lower overall energy utilization efficiency compared with the photovoltaic-thermal coupling system of the present invention.

[0154] In summary, the above-mentioned control examples are all lower than the photovoltaic-thermal coupling system in terms of photoelectric conversion efficiency; among them, the single flexible semi-transparent photovoltaic cell has an increased heat load due to the lack of infrared light reflection structure, which affects the efficiency; and the single trough / dish type solar thermal power station lacks photovoltaic cells and cannot achieve direct conversion of photoelectric energy, and the overall energy efficiency is low, which shows that the photovoltaic-thermal coupling system of the present invention has more advantages in comprehensive energy utilization.

[0155] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements 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 flexible semi-transparent photovoltaic cell structure with infrared light reflection function, characterized in that: From bottom to top, a curved reflector, a base layer, a first transparent electrode and / or a first transmission layer, a light absorption layer, a second transmission layer and / or a second transparent electrode, and a packaging layer are sequentially arranged; wherein: The first transport layer is a hole transport layer, and the second transport layer is an electron transport layer; or, the first transport layer is an electron transport layer, and the second transport layer is a hole transport layer; The substrate layer is a flexible high-transmittance substrate, which is attached to the surface of the curved reflector; or, the substrate layer is a flexible spectrally selective reflective layer, which is directly prepared on the surface of the curved reflector.

2. The flexible semi-transparent photovoltaic cell structure according to claim 1, characterized in that: The curved reflector comprises a curved substrate, and a high-reflectivity metal layer and a weather-resistant protective layer are sequentially arranged on the lower surface of the curved substrate.

3. The flexible semi-transparent photovoltaic cell structure according to claim 1, characterized in that: The flexible spectrally selective transflective layer comprises an infrared transmission film layer arranged on a curved reflector, on which titanium dioxide layers and magnesium fluoride layers are alternately arranged.

4. The method for preparing a flexible semi-transparent photovoltaic cell structure according to any one of claims 1 to 3, characterized in that: The steps include: S1: Preparation of curved reflector; S2: preparing a flexible high-transmittance substrate, and sequentially preparing a first transparent electrode and / or a first transmission layer, a light absorption layer, a second transmission layer and / or a second transparent electrode, and an encapsulation layer on the flexible high-transmittance substrate, and then attaching the flexible high-transmittance substrate to the upper surface of the curved reflector; Alternatively, a flexible spectrally selective reflective layer, a first transparent electrode and / or a first transmission layer, a light absorbing layer, a second transmission layer and / or a second transparent electrode, and an encapsulation layer are sequentially prepared on the surface of the curved reflector; alternatively, a first transparent electrode and / or a first transmission layer, a light absorbing layer, a second transmission layer and / or a second transparent electrode, and an encapsulation layer are sequentially prepared on the surface of the curved reflector.

5. The preparation method according to claim 4, characterized in that: Step S1 includes: A) Fine polishing of the curved substrate; B) uniformly depositing a silver or aluminum film on the lower surface of a finely polished curved substrate to form a high reflectivity metal layer; C) depositing or spin-coating a polymer coating, aluminum oxide, SiO2 or TiO2 on the surface of the high reflectivity metal layer to form a weather-resistant protective layer.

6. The preparation method according to claim 4, characterized in that: The method for preparing a flexible high-transmittance substrate comprises: heating polyethylene terephthalate, polyimide or polyethylene naphthalate to a molten state and extruding it into a film, and then stretching and plasma cleaning it to obtain a flexible high-transmittance substrate adapted to a curved reflector; Preferably, the method for preparing the flexible spectrally selective reflective layer comprises: firstly depositing an infrared transparent film layer on the upper surface of the curved reflector, and then alternately depositing titanium dioxide layers and magnesium fluoride layers on the infrared transparent film layer to obtain the flexible spectrally selective reflective layer.

7. The preparation method according to claim 4, characterized in that: The preparation method of the first transparent electrode comprises: depositing indium tin oxide, zinc aluminum oxide or fluorine-doped tin oxide on a substrate layer, and then performing a heat treatment to obtain the first transparent electrode; Preferably, the method for preparing the hole transport layer comprises: depositing a hole transport material on the substrate layer, the first transparent electrode or the light absorption layer, and then performing an annealing treatment at 50-150° C. to prepare the hole transport layer; Preferably, the method for preparing the electron transport layer comprises: depositing the electron transport material on the substrate layer, the first transparent electrode or the light absorption layer, and then performing annealing treatment at 50-150° C. to obtain the electron transport layer.

8. The preparation method according to claim 4, characterized in that: The preparation method of the light absorption layer comprises: coating a perovskite precursor solution, a quantum dot solution, an organic solution, and a dye sensitization solution on a hole transport layer to form a perovskite film, and then performing an annealing treatment at 50-200° C. to obtain the light absorption layer; Preferably, the method for preparing the second transparent electrode comprises: depositing indium tin oxide, aluminum zinc oxide, silver nanowires or graphene on the light absorption layer or the second transmission layer to obtain the second transparent electrode.

9. The preparation method according to claim 4, characterized in that: The method for preparing the encapsulation layer comprises: hot pressing the encapsulation material on the outside of the entire battery structure after preparing the second transparent electrode in a vacuum or nitrogen atmosphere; Preferably, the packaging material is ethylene vinyl acetate, polyvinylidene fluoride, butyl rubber or silicone.

10. Application of the flexible semi-transparent photovoltaic cell structure described in any one of claims 1 to 3 or the flexible semi-transparent photovoltaic cell structure prepared by the preparation method described in any one of claims 4 to 9 in trough-type solar thermal power stations and dish-type solar thermal power stations.

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