Flexible semitransparent infrared light reflecting photovoltaic cell and photo-thermal power station provided with same

Abstract

The utility model provides a flexible semitransparent infrared light reflecting photovoltaic cell and a photo-thermal power station provided with the same. The flexible semitransparent infrared light reflecting photovoltaic cell 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 a packaging layer from bottom to top in sequence. Wherein the first transmission layer is one of a hole transmission layer and an electron transmission layer, the second transmission layer is the other one of the hole transmission layer and the electron transmission layer, and the substrate layer is a flexible high-transmittance substrate or a flexible spectrum selective transflective layer. The flexible semitransparent infrared light reflecting photovoltaic cell can be applied to groove 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 infrared light reflecting photovoltaic cell has wide application prospects.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic cells, in particular to a flexible semi-transparent infrared light reflecting photovoltaic cell and a photothermal power station equipped with the same. Background Art

[0002] Solar thermal technology primarily converts solar radiation into heat through heat collection devices, but the systems are relatively complex and require high investment costs. Photovoltaic technology primarily relies on converting sunlight into electricity, but is limited by the conversion efficiency of solar cells. Furthermore, most photovoltaic modules utilize rigid structures, making them difficult to integrate with complex-shaped heat collection systems. Flexible photovoltaic cells typically utilize novel materials such as organic solar cells and perovskite solar cells. These materials are lightweight, flexible, and can be bonded and applied to a variety of complex surfaces, greatly improving the designability and adaptability of photovoltaic modules.

[0003] Photovoltaic-thermal coupling system is expected to achieve efficient utilization of the entire solar energy spectrum, but the following problems still exist: 1) Insufficient spectrum utilization efficiency of existing photovoltaic and thermal systems: Traditional photovoltaic and thermal systems have certain waste in the utilization of the solar spectrum, especially when photovoltaic cells cannot make full use of infrared light, and thermal systems fail to efficiently capture ultraviolet light and visible light, resulting in low overall energy utilization efficiency of the system; 2) It is difficult to coordinate the use of photovoltaic cells and thermal systems: Photovoltaic cells absorb part of the sunlight for electrical energy conversion, but the photons that are not absorbed often cannot be efficiently used for thermal energy conversion in the thermal system, resulting in unclear division of labor in solar energy utilization, poor system coordination efficiency, and difficulty in achieving the desired effect. To work efficiently at the same time; 3) The problem of curved surface adaptability of photovoltaic cells and solar thermal reflectors: For curved solar thermal reflectors, such as trough or dish reflectors, the rigid structure of existing photovoltaic cells is difficult to fit with complex curved surfaces, and it is impossible to achieve full coverage of the curved reflectors, affecting the synergistic power generation efficiency of photovoltaic and solar thermal; at the same time, existing semi-transparent photovoltaic cells are difficult to achieve good spectral separation effects; 4) Insufficient system design complexity and flexibility: Traditional photovoltaic-thermal coupling systems are complex in design, difficult to install, and lack the flexibility of later maintenance and replacement, especially in the process of combining photovoltaic cells with solar thermal reflectors, which is difficult to perform simple and effective operations, limiting the large-scale application and deployment of the system.

[0004] In view of this, the present utility model is proposed. Utility Model Content

[0005] The purpose of the utility model is to provide a flexible semi-transparent infrared light reflecting photovoltaic cell and a photothermal power station equipped with the same, which significantly improves the synergistic utilization efficiency of photovoltaic power generation and photothermal utilization.

[0006] The flexible semi-transparent infrared light reflecting photovoltaic cell 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 sequence from bottom to top; wherein the first transmission layer is one of a hole transport layer and an electron transport layer, the second transmission layer is the other of the hole transport layer and the electron transport layer, and the substrate layer is a flexible high-transmittance substrate or a flexible spectrally selective transflective layer.

[0007] Furthermore, the curved reflector includes a curved substrate, and a high-reflectivity metal layer and a weather-resistant protective layer are sequentially provided on the lower surface of the curved substrate.

[0008] Furthermore, the thickness of the high reflectivity metal layer is 20 nm to 500 μm, and the thickness of the weather-resistant protective layer is 10 nm to 500 μm.

[0009] Furthermore, the thickness of the flexible high-transmittance substrate is 10-900 μm.

[0010] Furthermore, the flexible spectrally selective reflective layer includes an infrared transparent film layer arranged on the curved reflector, and titanium dioxide layers and magnesium fluoride layers are alternately arranged on the infrared transparent film layer.

[0011] Furthermore, the thickness of the infrared transmitting film layer is 100-500 nm.

[0012] Furthermore, the thickness of the titanium dioxide layer is 30-300 nm, and the thickness of the magnesium fluoride layer is 50-500 nm.

[0013] Furthermore, the total number of titanium dioxide layers and magnesium fluoride layers is 4-10 layers, and the total thickness is 300-800 nm.

[0014] Furthermore, the thickness of the light absorbing layer is 300-2000 nm.

[0015] The utility model also provides a solar thermal power station, which is provided with the above-mentioned flexible semi-transparent infrared light reflecting photovoltaic cell, and the solar thermal power station is a trough-type solar thermal power station or a dish-type solar thermal power station.

[0016] The utility model can effectively separate different wavelengths of sunlight by attaching or directly preparing other layers on the surface of the curved reflector, allowing infrared light to pass through and be used by the curved reflector for photothermal conversion, while reflecting ultraviolet light and visible light to flexible semi-transparent photovoltaic cells to improve photoelectric conversion efficiency, overcoming the problem of incomplete utilization of solar energy by a single photovoltaic or photothermal system in the prior art, realizing dual energy utilization after spectral separation, and significantly improving the overall solar energy conversion efficiency.

[0017] The flexible translucent infrared light reflecting photovoltaic cell of the utility model is a photovoltaic-thermal coupling system. Compared with the independent operation of traditional photovoltaic and thermal systems, the photovoltaic-thermal coupling system achieves a synergistic effect of the two by integrating the photovoltaic cell and the thermal system on the same curved reflector. The thermal energy conversion efficiency of the thermal system after integrating the photovoltaic cell is maintained at 60-80%, the photoelectric conversion efficiency of the photovoltaic cell is above 16%, and the photoelectric conversion efficiency of the photovoltaic-thermal coupling system can reach above 28%, thereby significantly improving the efficiency of photovoltaic power generation and photothermal utilization.

[0018] This flexible, semi-transparent, infrared-reflecting photovoltaic cell exhibits excellent mechanical flexibility, adapting to the complex shapes of curved reflectors. It is particularly suitable for applications with curved collector systems, such as trough and dish solar thermal power plants. Compared to traditional rigid photovoltaic modules, this flexible, semi-transparent infrared-reflecting photovoltaic cell can achieve full coverage of curved reflectors, improving the system's spectral utilization. Furthermore, the use of flexible materials simplifies installation and maintenance, enhancing the system's flexibility and reliability, making it particularly suitable for large-scale deployment in high-radiation areas.

[0019] The preparation process of the flexible translucent infrared light reflecting photovoltaic cell of the present invention is simple and can be applied to different application scenarios. During the preparation, other layers can be attached to the surface of the curved reflector, or other layers can be directly prepared on the surface of the curved reflector. The above two processes 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, which reduces costs and improves operability.

[0020] The flexible, semi-transparent, infrared-reflecting photovoltaic cell of this utility model, after being prepared as a multi-layer structure on the surface of the photothermal curved reflector, effectively prevents the adhesion of dust, dirt, and other environmental pollutants 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 functionally integrated design improves the service life and operating economy of the reflector system, providing a more sustainable solution for photothermal power applications. In addition, the encapsulation layer is used for protection, and it has good environmental adaptability and can resist the erosion of environmental factors such as water vapor and oxygen. The water vapor barrier rate reaches 99%, which extends the service life of the system and ensures the long-term durability of the cell in harsh environments; after 1000 hours of wet heat testing (85°C / 85% humidity), the performance degradation of this flexible, semi-transparent, infrared-reflecting photovoltaic cell is less than 10%, and it has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific implementation methods or the description of the prior art. 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 any creative work.

[0022] Figure 1 This is a schematic structural diagram of the adhesive-type flexible semi-transparent photovoltaic cell of Example 1;

[0023] Figure 2 Schematic diagram of the internal structure of the adhesive-type flexible semi-transparent photovoltaic cell of Example 1;

[0024] Figure 3 Schematic diagram of the internal structure of the integrated flexible semi-transparent photovoltaic cell of Example 2;

[0025] Figure 4 This is a comparison chart of infrared light transmittance of flexible spectrally selective reflective layers with different structures;

[0026] Figure 5 A comparison chart of the ultraviolet and visible light reflectivity of flexible spectrally selective reflective layers with different structures;

[0027] Figure 6 This is a schematic structural diagram of a trough-type solar thermal power station according to Example 3;

[0028] Figure 7 This is a structural diagram of a dish-type solar thermal power station in Example 4.

[0029] Description of reference numerals:

[0030] 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

[0031] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0032] 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 also includes the plural. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0033] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] Example 1

[0035] Combine Figure 1 、 Figure 2 As shown, the flexible semi-transparent infrared light reflecting photovoltaic cell (also called photovoltaic thermal coupling system) of this embodiment is provided with a curved reflector 1, a flexible high-transmittance substrate 3, a first transparent electrode 4, a hole transport layer 5, a light absorption layer 6, an electron transport layer 7, a second transparent electrode 8 and an encapsulation layer 9 in sequence from bottom to top.

[0036] The curved reflector 1 includes a curved substrate, on the lower surface of which a high-reflectivity metal layer and a weather-resistant protective layer are sequentially provided; 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; the material of the weather-resistant protective layer can be a weather-resistant material such as aluminum oxide, a polymer coating, SiO2, TiO2, and the thickness of the weather-resistant protective layer can be 10nm-500μm. Specifically, a silver or aluminum film can be uniformly deposited on the lower surface of the finely polished curved substrate by vacuum evaporation or magnetron sputtering to form a high-reflectivity metal layer; subsequently, a polymer coating, aluminum oxide, SiO2 or TiO2 is deposited or spin-coated on 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. In this embodiment, the material of the high-reflectivity metal layer is a silver film with a thickness of 100nm; the material of the weather-resistant protective layer is SiO2 with a thickness of 80nm.

[0037] The flexible, highly transparent substrate 3 is used to support the photovoltaic layer and must have high light transmittance and mechanical flexibility. The thickness of the flexible, highly transparent substrate 3 can be 10-900 μm. Specifically, polyethylene terephthalate (PET), polyimide (PI), or polyethylene naphthalate (PEN) can be heated to a molten state through a melt extrusion process, then extruded into a film and stretched to enhance its mechanical properties. Stretching can be performed using the following methods:

[0038] 1) Preheating and stretching: The extruded film is first heated to a temperature close to the melting point (for example, PET substrate can be heated to 70-90°C) to moderately relax its molecular chains. Preheating and stretching helps to achieve uniform stretching, thereby improving the transparency and surface smoothness of the flexible and highly transparent substrate.

[0039] 2) Longitudinal stretching: The preheated film is stretched in the longitudinal direction (in line with the extrusion direction) on a longitudinal stretching device to make the molecular chains more densely 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.

[0040] 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 the expected performance.

[0041] 4) Biaxial stretching: In some cases, biaxial stretching can be performed to enhance the uniformity of the film in all directions, i.e., stretching in both the longitudinal and transverse directions. This step is usually performed on a multiaxial stretching machine to ensure that the strength and flexibility of the substrate remain consistent in all directions.

[0042] 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℃), the molecular chains are readjusted to ensure the stability of the film size and reduce shrinkage or deformation during subsequent use.

[0043] After stretching, the surface of the film is treated with plasma cleaning to enhance its adhesion to subsequent coatings. In this embodiment, the flexible high-transmittance substrate 3 is made of PET with a thickness of 60 μm.

[0044] The first transparent electrode 4 is deposited on the flexible high-transmittance substrate 3 and is used to collect carriers in the flexible semi-transparent photovoltaic cell 2 while ensuring high light transmittance. The thickness of the first transparent electrode 4 can be 50-150nm. Specifically, indium tin oxide, aluminum zinc oxide or fluorine-doped tin oxide material is deposited on the flexible high-transmittance substrate 3 by magnetron sputtering. In order to ensure the uniformity of the first transparent electrode 4, a multi-target rotary sputtering process can be used. Subsequently, the conductivity and light transmittance of the film are enhanced by heat treatment. The heat treatment temperature can be 100-300°C and the heat treatment time can be 10-100min. In this embodiment, the material of the first transparent electrode 4 is indium tin oxide, the thickness is 30nm, the heat treatment temperature is 150°C, and the heat treatment time is 10min.

[0045] The hole transport layer 5 is deposited on the first transparent electrode 4 to effectively transport the holes generated by the light absorption layer 6 and prevent the reverse transmission of electrons; the thickness of the hole transport layer 5 can be 10-50nm. Specifically, the hole transport material (for example: poly (3,4-ethylenedioxythiophene) - polystyrene sulfonate, poly [bis (4-phenyl) (2,4,6-trimethylphenyl) amine], nickel oxide, etc.) is deposited on the first transparent electrode 4 by solution spin coating, and then annealed at 50-150 ° C. The annealing time can be 0-60min to remove the solvent and enhance the stability of the layer. In this embodiment, the material of the hole transport layer 5 is poly (3,4-ethylenedioxythiophene) - polystyrene sulfonate, the thickness is 20nm, the annealing temperature is 80 ° C, and the annealing time is 10min.

[0046] The light-absorbing layer 6, deposited on the hole-transporting layer 5, is the core component of the flexible semi-transparent photovoltaic cell 2 and is responsible for converting sunlight into electron-hole pairs. The light-absorbing layer 6 is a perovskite light-absorbing layer, and the thickness of the light-absorbing layer 6 can be 300-2000 nm. Specifically, a perovskite precursor solution, a quantum dot solution, an organic solution, and a dye-sensitizing solution are applied to the hole-transporting layer 5 by solution spin coating, and a uniform perovskite film is formed by wet chemical deposition. Subsequently, the film is annealed at 60-180°C for 10-120 minutes to form a well-crystallized perovskite light-absorbing layer. In this embodiment, the thickness of the light-absorbing layer 6 is 500 nm, the annealing temperature is 100°C, and the annealing time is 30 minutes.

[0047] The electron transport layer 7 is deposited on the light absorbing layer 6 to conduct the electrons generated in the light absorbing layer 6 to the second transparent electrode 8. The thickness of the electron transport layer 7 can be 20-50 nm. Specifically, the electron transport material (for example, fullerene, tin oxide, [6,6]-phenyl-C 61-methyl butyrate, nanocrystalline TiO2, etc.) is deposited on the light absorbing layer 6, and then annealed at 70-120°C for 10-60 minutes to enhance the crystallinity and electron transport properties of the layer. In this embodiment, the material of the electron transport layer 7 is [6,6]-phenyl-C 61 -methyl butyrate, thickness is 20 nm, annealing temperature is 70°C, and annealing time is 10 min.

[0048] The second transparent electrode 8 is deposited on the electron transport layer 7 to collect electrons and conduct current while maintaining light transmittance. The thickness of the second transparent electrode 8 can be 30-200nm. Specifically, indium tin oxide, aluminum zinc oxide, silver nanowires or graphene are uniformly deposited on the electron transport layer 7 by magnetron sputtering or thermal evaporation, and then heat treated. The heat treatment temperature can be 80-150°C and the heat treatment time can be 5-15min. For graphene or silver nanowires, spin coating or spraying methods are usually used, and the transfer process is carried out in conjunction with a flexible substrate. In this embodiment, the material of the second transparent electrode 8 is indium tin oxide, the thickness is 30nm, the heat treatment temperature is 150°C, and the heat treatment time is 5min.

[0049] The encapsulation layer 9 is located above the second transparent electrode 8 and is used to protect the battery from the erosion of moisture and oxygen in the environment and extend the battery life; the thickness of the encapsulation layer 9 can be 50-500μm. Specifically, a lamination process is used to hot-press the encapsulation material (ethylene-vinyl acetate, polyvinylidene fluoride, butyl rubber, silicone) in a vacuum or nitrogen atmosphere at a temperature of 100-200°C for 3-10 minutes, so that it is tightly wrapped around the outside of the entire battery structure to prevent damage to the battery caused by environmental factors, thereby obtaining a flexible translucent photovoltaic cell 2 (referred to as a photovoltaic cell for short). In this embodiment, the encapsulation layer 9 is made of ethylene-vinyl acetate, has a thickness of 200μm, a hot-pressing temperature of 120°C, and a hot-pressing time of 10 minutes.

[0050] After the flexible semi-transparent photovoltaic cell 2 is prepared, it can be attached to the surface of the curved reflector 1 through an adhesive layer, as follows:

[0051] Surface cleaning: Before attaching the flexible semi-transparent photovoltaic cell 2 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 blown dry with nitrogen.

[0052] Adhesive layer coating: an adhesive (such as a high-performance silicone adhesive, a UV-curing adhesive, etc.) is evenly coated on the surface of the curved reflector 1 to form an adhesive layer. The coating thickness of the adhesive can be 100-200 μm. After coating, wait for a few minutes to allow the adhesive layer to dry slightly to a semi-cured state for subsequent pasting operations.

[0053] Positioning of the flexible semi-transparent photovoltaic cell 2: gradually place the prepared flexible semi-transparent photovoltaic cell 2 on the adhesive layer, starting from one side and gradually bonding them, ensuring 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 uniform.

[0054] Compression and curing treatment: Use a vacuum compression system, roller press, etc. to compress the entire system, maintain uniform pressure to ensure that the bonding between the flexible translucent photovoltaic cell 2 and the curved reflector 1 is complete and firm; the compression treatment time can be 30 minutes to 1 hour 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.

[0055] The flexible semi-transparent infrared light reflecting photovoltaic cell of this embodiment not only has good surface adaptability, but also allows some light to pass through, thereby realizing the dual utilization of different bands in the spectrum. The flexible semi-transparent photovoltaic cell 2 absorbs the visible light band to generate electricity, while the infrared light that is not absorbed passes through the flexible semi-transparent photovoltaic cell 2 and is reflected back to the thermal energy collection system by the curved reflector 1, thereby realizing efficient synergy between photovoltaics and photothermal energy. The flexible semi-transparent photovoltaic cell 2 can be flexibly applied on different curved reflectors 1, especially when combined with a solar collection system of a trough, dish or parabolic reflector, thereby improving the spectral utilization rate of the system; at the same time, the flexible semi-transparent photovoltaic cell 2 can not only generate electricity efficiently, but also reflect long-wave photons through the flexible semi-transparent photovoltaic cell 2 to the photothermal system, thereby increasing the utilization of thermal energy without losing electrical energy efficiency.

[0056] After testing, the thermal energy conversion efficiency of the flexible semi-transparent infrared light reflecting photovoltaic cell 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 damp heat test was carried out under conditions of 85°C and 85% humidity. The results show that the performance degradation of the flexible semi-transparent infrared light reflecting photovoltaic cell of this embodiment is 10%. Example 2

[0057] Combine Figure 3 As shown, the flexible semi-transparent infrared light reflecting photovoltaic cell (also called photovoltaic thermal coupling system) of this embodiment is provided with a curved reflector 1, a flexible spectrally selective reflective layer 10, a first transparent electrode 4, a hole transport layer 5, a light absorption layer 6, an electron transport layer 7, a second transparent electrode 8 and an encapsulation layer 9 in sequence from bottom to top.

[0058] The curved substrate is finely polished, and then an aluminum film is uniformly deposited on the lower surface of the finely polished curved substrate using a magnetron sputtering process to form a high-reflectivity metal layer with a thickness of 200 nm. Subsequently, TiO2 is deposited on the surface of the high-reflectivity metal layer using a chemical vapor deposition method to form a weather-resistant protective layer with a thickness of 100 nm, thereby producing a curved reflector 1.

[0059] The flexible spectrally selective reflective layer 10 includes an infrared transparent film layer arranged on the curved reflector 1, on which titanium dioxide layers and magnesium fluoride layers (collectively referred to as the selective reflective layer) are alternately arranged; wherein the material of the infrared transparent film layer can be silicon dioxide, silicon nitride, etc., and the thickness of the infrared transparent film layer can be 100-500nm, preferably 100-300nm, and the infrared transparent 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 layers of the titanium dioxide layer and the magnesium fluoride layer is 4-10 layers, and the total thickness is 300-800nm.

[0060] Specifically, an infrared-transmitting film material (such as silicon dioxide or silicon nitride) can be deposited on the curved reflector 1 using sputtering, chemical vapor deposition, physical vapor deposition, or other methods to form an infrared-transmitting film layer. This infrared-transmitting film layer exhibits excellent infrared light transmittance and mechanical durability. To enhance ultraviolet and visible light reflection, titanium dioxide and magnesium fluoride are sequentially deposited on the infrared-transmitting film layer to form a titanium dioxide layer and a magnesium fluoride layer. By adopting a design with alternating high and low refractive indices, an interference film structure capable of reflecting both ultraviolet and visible light is formed.

[0061] In this embodiment, silicon dioxide is first deposited on the surface of the curved reflector 1 by physical vapor deposition to form an infrared transparent film layer with a thickness of 200 nm; then, titanium dioxide layers and magnesium fluoride layers are alternately deposited on the infrared transparent film layer, with each titanium dioxide layer having a thickness of 50 nm and each magnesium fluoride layer having a thickness of 100 nm. Three layers of titanium dioxide layers and three layers of magnesium fluoride layers (collectively referred to as selective reflective layers) are deposited to obtain a flexible spectrally selective reflective layer 10 having three selective reflective layers. 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%.

[0062] Zinc aluminum oxide was deposited on the flexible spectrally selective reflective layer 10 by a multi-target rotational sputtering method, and then heat treated at 150° C. for 30 minutes to obtain a first transparent electrode 4 with a thickness of 100 nm.

[0063] 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 100° C. for 10 minutes to prepare a hole transport layer 5 with a thickness of 40 nm.

[0064] The raw materials were dissolved in DMF and DMSO according to the ratio of cesium iodide: methylammonium iodide: formamidine hydroiodide: lead iodide: lead bromide = 1:3:16:14:8 to prepare a perovskite precursor solution. Subsequently, the perovskite precursor solution was coated on the hole transport layer 5 by solution spin coating, and a uniform perovskite film was formed by wet chemical deposition. The film was annealed at 150°C for 30 minutes to obtain a light absorption layer 6 with a thickness of 400 nm and good crystallization.

[0065] C60 and bathocuproin were deposited on the light absorbing layer 6 by thermal evaporation to prepare an electron transporting layer 7 with a thickness of 50 nm.

[0066] Zinc aluminum oxide was uniformly deposited on the electron transport layer 7 by magnetron sputtering, and then heat-treated at 100° C. for 15 minutes to obtain a second transparent electrode 8 with a thickness of 80 nm.

[0067] The polyvinylidene fluoride was hot-pressed onto the surface of the second transparent electrode 8 at 130° C. in a nitrogen atmosphere by a lamination process for 10 minutes to obtain an encapsulation layer 9 with a thickness of 150 μm.

[0068] After testing, the thermal energy conversion efficiency of the flexible semi-transparent infrared light reflecting photovoltaic cell 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 damp heat test was carried out under conditions of 85°C and 85% humidity; the results showed that the performance degradation of the flexible semi-transparent infrared light reflecting photovoltaic cell of this embodiment was 5%.

[0069] Example 3

[0070] This embodiment provides a trough-type solar thermal power station, which is equipped with the flexible semi-transparent infrared light reflecting photovoltaic cell of embodiment 2.

[0071] Combine Figure 6As shown, flexible semi-transparent infrared-reflecting photovoltaic cells are covered on the trough reflectors to form a photovoltaic-thermal coupling system. When sunlight 12 strikes the flexible semi-transparent infrared-reflecting photovoltaic cells, ultraviolet and visible light are absorbed by the flexible semi-transparent photovoltaic cells 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 infrared-reflecting photovoltaic cells to receive as much sunlight as possible. By integrating the flexible semi-transparent photovoltaic cells 2 on the trough reflectors, the dual benefits of photovoltaic power generation and solar thermal utilization are achieved, significantly improving the overall energy efficiency of the trough solar thermal power station. In particular, the flexible semi-transparent infrared-reflecting photovoltaic cells can adapt to the curved shape of the trough collector, simplifying 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 cells work in conjunction with the solar thermal system, without affecting the heat collection efficiency, and can also increase the power output of the power station.

[0072] Example 4

[0073] This embodiment provides a trough-type solar thermal power station, which is equipped with the flexible semi-transparent infrared light reflecting photovoltaic cell of embodiment 2.

[0074] Combine Figure 7 As shown, flexible semi-transparent infrared light reflecting photovoltaic cells are covered on the dish reflector to form a photovoltaic thermal coupling system. When sunlight 12 hits the flexible semi-transparent infrared light reflecting photovoltaic cells, ultraviolet light and visible light are absorbed by the flexible semi-transparent photovoltaic cells 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 infrared light reflecting photovoltaic cells 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 infrared light reflecting photovoltaic cells enables it to fit tightly to the surface of the dish reflector without making major changes to the existing structure of the solar thermal power station. The application of flexible semi-transparent infrared light reflecting photovoltaic cells to the complex curved surface of the dish reflector further enhances the integration and design freedom of the photovoltaic thermal coupling system. The semi-transparent properties of the flexible semi-transparent infrared-reflecting photovoltaic cell 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.

[0075] Comparative Example 1: A selectively reflective layer

[0076] Except that only one selective reflective layer is provided in the flexible spectrally selective reflective layer, the rest is substantially the same as in Example 2.

[0077] The steps for preparing the flexible spectrally selective reflective layer of this comparative example are as follows:

[0078] 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.

[0079] 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 titanium dioxide layer and one magnesium fluoride layer are deposited to obtain a flexible spectrally selective reflective transmission layer 10 .

[0080] Combine 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 infrared light reflecting photovoltaic cell 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%.

[0081] Comparative Example 2: No selective reflective layer

[0082] Except that the flexible spectrally selective reflective layer is not provided with a selective reflective layer (ie, only an infrared transmitting film layer is provided), the rest is the same as that of Example 2.

[0083] The steps for preparing the flexible spectrally selective reflective layer of this comparative example are as follows:

[0084] Silicon dioxide is deposited on the surface of the curved reflector 1 by physical vapor deposition to form an infrared transparent film layer with a thickness of 200 nm. The infrared transparent film layer allows infrared light to pass through, but has limited selective reflection effect on ultraviolet light and visible light.

[0085] Combine 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 infrared light reflecting photovoltaic cell 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%.

[0086] Comparative Example 3: Flexible semi-transparent photovoltaic cell alone

[0087] 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.

[0088] 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.

[0089] After testing, the photoelectric conversion efficiency of the flexible semi-transparent photovoltaic cell alone in this control example is 16%, which is lower than the photoelectric efficiency in the coupled system, and lacks the infrared light reflection function. Therefore, the thermal load of the light absorption layer is high, which is not conducive to the long-term stability of the cell.

[0090] Comparative Example 4: Single Trough / Dish CSP System

[0091] In this comparative example, a single trough-type solar thermal power station or dish-type solar thermal power station system adopts an independent solar thermal collector structure and does not have a photovoltaic cell structure. The solar thermal system structure mainly includes: a high-reflectivity curved reflector (trough / dish reflector), a heat absorption tube and a heat transfer medium.

[0092] The preparation steps for a single trough / dish CSP power station system in this comparative example are as follows:

[0093] 1) Installation of heat absorption tubes: High-efficiency heat absorption tubes are installed at the focusing position of the trough / dish solar thermal power station. The surface of the heat absorption tubes is coated with a selective absorption coating to optimize the visible light absorption efficiency and reduce thermal radiation loss.

[0094] 2) Addition of heat transfer medium: The heat absorption tube is filled with high-temperature thermal 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, ultimately driving the power generation system.

[0095] In this comparative example, the thermal energy conversion efficiency of a single trough solar thermal power station was 50%, and the photovoltaic conversion efficiency was 15%. The thermal energy conversion efficiency of a single dish solar thermal power station was 60%, and the photovoltaic conversion efficiency was 20%. Due to the lack of photovoltaic modules' photovoltaic conversion capacity, the overall energy utilization efficiency of a single trough / dish solar thermal power station system is lower than that of the photovoltaic-thermal coupled system of the present invention.

[0096] 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. This shows that the photovoltaic-thermal coupling system of the present invention has more advantages in comprehensive energy utilization.

[0097] 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 above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flexible semi-transparent infrared light reflecting photovoltaic cell, 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 an encapsulation layer are arranged in sequence; wherein, the first transmission layer is one of a hole transport layer and an electron transport layer, the second transmission layer is the other of the hole transport layer and the electron transport layer, and the base layer is a flexible high-transmittance base or a flexible spectrally selective transflective layer.

2. The flexible semi-transparent infrared light reflecting photovoltaic cell 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 infrared light reflecting photovoltaic cell according to claim 2, characterized in that: The thickness of the high reflectivity metal layer is 20 nm to 500 μm, and the thickness of the weather-resistant protective layer is 10 nm to 500 μm.

4. The flexible semi-transparent infrared light reflecting photovoltaic cell according to claim 1, characterized in that: The thickness of the flexible high-transmittance substrate is 10-900 μm.

5. The flexible semi-transparent infrared light reflecting photovoltaic cell 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.

6. The flexible semi-transparent infrared light reflecting photovoltaic cell according to claim 5, characterized in that: The thickness of the infrared transmitting film layer is 100-500nm.

7. The flexible semi-transparent infrared light reflecting photovoltaic cell according to claim 5, characterized in that: The thickness of the titanium dioxide layer is 30-300 nm, and the thickness of the magnesium fluoride layer is 50-500 nm.

8. The flexible semi-transparent infrared light reflecting photovoltaic cell according to claim 5, characterized in that: The total number of titanium dioxide layers and magnesium fluoride layers is 4-10 layers, and the total thickness is 300-800 nm.

9. The flexible semi-transparent infrared light reflecting photovoltaic cell according to claim 1, characterized in that: The thickness of the light absorbing layer is 300-2000 nm.

10. A solar thermal power station, characterized in that: The invention is provided with a flexible semi-transparent infrared light reflecting photovoltaic cell as described in any one of claims 1 to 9, and the solar thermal power station is a trough solar thermal power station or a dish solar thermal power station.

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