Solar energy comprehensive utilization coupling structure and preparation method and application thereof

Abstract

The invention provides a solar energy comprehensive utilization coupling structure and a preparation method and application thereof. The solar energy comprehensive utilization coupling structure comprises a semitransparent photovoltaic cell, a photo-thermal reflecting mirror, a spectrum frequency divider, a non-transparent photovoltaic cell and a photo-thermal heat collector, and the semitransparent photovoltaic cell absorbs ultraviolet light and visible light in a solar spectrum; the photo-thermal reflecting mirror is located below the semitransparent photovoltaic cell and reflects the residual spectrum which is not absorbed by the semitransparent photovoltaic cell, the spectrum frequency divider divides near-infrared light and far-infrared light in the residual spectrum to the opaque photovoltaic cell and the photo-thermal heat collector respectively, and the opaque photovoltaic cell conducts photovoltaic power generation through the near-infrared light. And the photo-thermal heat collector utilizes far infrared light to carry out photo-thermal power generation. According to the coupling structure, the purpose of fully utilizing sunlight can be achieved, the cooperative utilization efficiency of photovoltaic power generation and photo-thermal power generation is improved, and the coupling structure can be widely applied to tower type, groove type, disc type, Fresnel type and other photo-thermal power stations.

Description

Technical Field

[0001] The present invention relates to the technical field of solar energy utilization, and in particular to a solar energy comprehensive utilization coupling structure and a preparation method and application thereof. Background Art

[0002] As global energy demand continues to grow, solar energy, as a clean, efficient and renewable energy source, has become a research focus in the energy field. At present, the use of solar energy is mainly concentrated in the two major technical fields of photovoltaic power generation and solar thermal power generation. Photovoltaic power generation directly converts sunlight into electrical energy through the photoelectric effect of semiconductor materials, and has the advantages of flexible installation and low operating costs; however, due to the band gap limitations of materials and temperature effects, the energy conversion efficiency of photovoltaic technology has been difficult to reach a theoretically high level. On the other hand, solar thermal power generation converts sunlight into thermal energy through collectors to drive thermal cycle power generation. Its advantages are flexible energy storage, adaptability to large-scale grid regulation, and the ability to provide stable and continuous power output, but the initial construction cost is high, and it is highly dependent on areas with concentrated light resources.

[0003] In order to further improve the comprehensive utilization efficiency of solar energy, photovoltaic power generation and solar thermal power generation technology can be combined to overcome their respective limitations. This photovoltaic and solar thermal coupling technology can not only make full use of the wide spectrum range of sunlight, but also improve the overall energy conversion efficiency through reasonable design and structural optimization. Especially for solar energy applications in high temperature environments, such as the combination of solar thermal power generation and high-efficiency photovoltaic modules, the conversion rate and economy of solar energy can be effectively improved. In this context, an integrated system combining photovoltaic and solar thermal technologies has emerged. This system realizes the multiple utilization of solar energy by organically combining photovoltaic cells with solar thermal collectors, which can improve the overall operating efficiency of the system while meeting electricity demand. In addition, the coupling system combining solar thermal and photovoltaic can better cope with the challenges of different geographical environments and climatic conditions, has strong adaptability, and can provide more reliable and efficient solutions for diversified energy needs.

[0004] At present, the existing technologies have the following problems: 1) It is usually difficult for a single photovoltaic or solar thermal system to cover the entire solar spectrum, resulting in insufficient utilization of light energy in some bands and low overall efficiency; 2) It is difficult to accurately guide different bands of sunlight to the most suitable power generation components, resulting in limited light energy utilization and system performance; 3) The combination of photovoltaic cells and solar thermal reflectors has great limitations, fails to optimize the synergy between the two, and lacks flexible structural design to adapt to different optical path requirements. Therefore, how to improve the performance of this coupling technology and reduce costs through innovative design and new material development has become one of the hot research topics in the field of new 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 solar energy comprehensive utilization coupling structure and its preparation method and application, which can fully utilize sunlight and improve the coordinated utilization efficiency of photovoltaic power generation and solar thermal power generation.

[0007] The present invention provides a solar energy comprehensive utilization coupling structure, comprising a semi-transparent photovoltaic cell, a photothermal reflector, a spectrum divider, an opaque photovoltaic cell and a photothermal collector. The semi-transparent photovoltaic cell absorbs ultraviolet light and visible light in the solar spectrum. The photothermal reflector is located below the semi-transparent photovoltaic cell and reflects the remaining spectrum not absorbed by the semi-transparent photovoltaic cell. The spectrum divider divides the near-infrared light and the far-infrared light in the remaining spectrum to the opaque photovoltaic cell and the photothermal collector respectively. The opaque photovoltaic cell uses the near-infrared light to perform photovoltaic power generation, and the photothermal collector uses the far-infrared light to perform photothermal power generation.

[0008] The solar energy comprehensive utilization coupling structure of the present invention realizes the efficient distribution and comprehensive utilization of solar energy through spectrum separation technology and multi-layer structure design. The coupling structure can accurately guide the different bands of the solar spectrum to the most suitable power generation components, give full play to the performance advantages of each power generation component, and significantly improve the overall conversion efficiency of photoelectric and photothermal.

[0009] Below, each component is described in detail as follows:

[0010] (1) Semi-transparent photovoltaic cells

[0011] Semi-transparent photovoltaic cells are mainly used to absorb ultraviolet and visible light in the range of 200-800nm ​​in the solar spectrum, and have good photoelectric conversion efficiency and transmittance characteristics. Materials that can be used for semi-transparent photovoltaic cells include rigid / flexible perovskite solar cells or other semi-transparent thin-film solar cells. A transmittance-enhancing layer can be set on the surface of the semi-transparent photovoltaic cell to optimize transmittance while reducing interface reflection losses. Semi-transparent photovoltaic cells can be combined with photothermal reflectors by direct deposition or other fixing methods (such as gluing, snapping, etc.), and can be designed to fit the photothermal reflector, or at a certain angle to optimize the light incident angle. In addition, the anti-ultraviolet aging and environmental tolerance performance can be enhanced by adding a transparent encapsulation layer.

[0012] Specifically, the semi-transparent photovoltaic cell is provided with a substrate, a first transparent conductive layer, a first transmission layer, a light absorption layer, a second transmission layer, a second transparent conductive layer and an encapsulation layer in order from bottom to top, and the first transmission layer and the second transmission layer are hole transmission layers or electron transmission layers; the specific details of each layer are as follows:

[0013] Substrate: High-transmittance rigid glass or flexible substrate is used, and the thickness of the substrate is 0.1-2 mm, for example, 0.2-2 mm.

[0014] Transparent conductive layer: Made of ITO (indium tin oxide), ATO (antimony tin oxide), etc., prepared by radio frequency magnetron sputtering, with a thickness of 50-300nm, such as 150-300nm, and a transmittance higher than 90%.

[0015] Light absorption layer: Perovskite-based perovskite layer, such as MAPbI3, MAPbBr3, CsFA-MAPb(Br x I 1-x )3, etc., prepared by solution spin coating, vacuum co-evaporation, blade coating and other methods, with a thickness of 300-700nm, for example, 500-700nm; in addition, it can be combined with surface passivation technology (such as long-chain amine salt passivation) to achieve high photoelectric conversion efficiency and transmittance.

[0016] Electron transport layer: using C60, SnO2, TiO2 and other materials, prepared by sol-gel method, vacuum evaporation and other methods, with a thickness of 20-100nm, for example, 30-100nm, to optimize electron extraction and transmission capabilities.

[0017] Hole transport layer: organic small molecule materials such as Spiro-OMeTAD (2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene), PTAA (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]), polymer materials such as PEDOT:PSS (poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate), P3HT (poly(3-hexylthiophene)), and inorganic materials such as NiOx and CuSCN are prepared by sol-gel method, vacuum evaporation, etc., with a thickness of 20-100 nm, for example, 40-100 nm.

[0018] Encapsulation layer: Flexible high light-transmittance polymer (such as PEVA, PET, PI, etc.) is used, and encapsulation is completed through a vacuum lamination process. The thickness of the encapsulation layer is 10-9000μm, for example, 250-500μm, to ensure environmental stability and mechanical flexibility.

[0019] The structure of the semi-transparent photovoltaic cell is optimized as follows:

[0020] (1) Enhanced spectral selectivity structure

[0021] In order to enhance the spectral selectivity, quantum dots or photosensitive materials can be introduced into the perovskite layer to achieve selective absorption and transmission of light in a specific band; specifically, the absorption of ultraviolet and visible light in the 200-800nm ​​band is optimized, while the transmittance in the 800-1200nm band is enhanced, aiming to improve the photoelectric conversion efficiency of photovoltaic cells while providing sufficient infrared light for the photovoltaic thermal components in the photovoltaic-thermal integrated system.

[0022] By introducing quantum dots or photosensitive materials to form composite materials with perovskites, the optical properties of different materials in different bands can be fully utilized to improve the utilization efficiency of the entire spectral range. It can not only improve the photoelectric conversion efficiency of photovoltaic cells, but also maximize the transmittance of the unabsorbed spectrum, ensuring that the photothermal components can receive sufficient infrared light, thereby achieving efficient energy utilization in the photovoltaic and thermal integrated system.

[0023] The perovskite material of the perovskite layer can be selected from perovskite materials with suitable band gap and photoelectric properties, such as a band gap range of 1.65-2.30eV, to ensure that it has good absorption performance in the visible light range; quantum dot materials can be selected from quantum dots such as CdSe, PbS, etc. These quantum dots are small in size, have quantum confinement effects, and can enhance light absorption in specific bands; photosensitive materials can use organic photosensitizing dyes, which have a high light absorption coefficient and good stability.

[0024] The preparation method of quantum dots is as follows:

[0025] 1) Hydrothermal synthesis method: Place a precursor solution containing metal ions and chalcogen ions into a high-pressure reactor and react at a certain temperature and pressure for a period of time to obtain quantum dots. By controlling the reaction conditions such as temperature, time, precursor concentration, etc., the size and optical properties of the quantum dots can be adjusted.

[0026] 2) Hot injection method: The metal precursor is quickly injected into a high-temperature organic ligand solution to initiate a reaction to generate quantum dots; this method can produce quantum dots with uniform size and high crystallinity.

[0027] The preparation method of the photosensitive material is as follows:

[0028] The photosensitizer is prepared by chemical synthesis and organic synthesis reaction; according to the different structures of photosensitizers, the appropriate synthesis route and reaction conditions are selected.

[0029] The method of introducing quantum dots or photosensitive materials into the perovskite layer is as follows:

[0030] 1) Solution mixing method: The prepared quantum dots or photosensitive materials are dispersed in an appropriate solvent, mixed evenly with the perovskite precursor solution, and then the mixed solution is deposited on the substrate by spin coating, spraying or printing to form a perovskite layer; during the drying and annealing process, the quantum dots or photosensitive materials interact with the perovskite to achieve the effect of enhancing spectral selectivity.

[0031] 2) In-situ growth method: During the preparation of the perovskite layer, the precursors of quantum dots or photosensitive materials are introduced to form composite materials synchronously during the growth of the perovskite; for example, during the chemical vapor deposition or solution growth of the perovskite, quantum dot precursors are added, and the reaction conditions are controlled to allow the quantum dots to grow in the perovskite crystal.

[0032] Through the above optimization method, the enhanced spectral selectivity design can be effectively applied in the photovoltaic-thermal integrated system to improve the comprehensive energy utilization efficiency.

[0033] (2) Controllable transmittance structure design

[0034] In order to achieve controllable transmittance, optical microstructures such as periodic gratings, microlens arrays, etc. can be introduced inside the perovskite layer to achieve dynamic control of the transmittance; this method can flexibly adjust the transmittance of photovoltaic cells according to different lighting conditions and actual needs, thereby optimizing the energy distribution of photovoltaic and photothermal systems.

[0035] Periodic gratings, microlens arrays, etc. are key optical microstructures that can finely control the incident light. Among them, periodic gratings diffract the incident light through periodic grooves or protrusions, thereby changing the propagation direction and intensity distribution of the light. The microlens array is composed of multiple tiny lenses, which can focus or disperse the incident light and further adjust the propagation path and energy distribution of the light. The above dynamic adjustment capability enables photovoltaic cells to optimize the absorption and transmission spectral characteristics under different lighting conditions. For example, in the summer when the light is strong, the transmittance can be reduced to improve the stability of the photovoltaic cell; and in the winter when the light is weak, the transmittance can be increased to provide more energy for the solar thermal system.

[0036] For areas with large seasonal changes in light, the above-mentioned controllable transmittance structure design can automatically adjust the energy distribution of photovoltaic and solar thermal according to the characteristics of light in different seasons; in seasons with sufficient light, the power generation needs of the photovoltaic system are met first; and in seasons with insufficient light, the energy collection of the solar thermal system is appropriately increased to improve the energy utilization efficiency of the entire system. In addition to seasonal changes, the design can also be dynamically adjusted according to actual energy needs; for example, during peak electricity consumption during the day, the power generation efficiency of photovoltaic cells can be improved to provide more electricity to the power grid; and at night or during low-load periods, more energy can be allocated to the solar thermal system for heating or hot water supply.

[0037] The working mechanism of periodic grating is as follows: Periodic grating is an optical element with a periodic structure, and its effect on light is mainly based on the principle of diffraction. When light is irradiated on the grating, light of different wavelengths will be diffracted to different degrees according to the period of the grating and the incident angle. By reasonably designing the parameters such as the period, depth and width of the grating, the diffraction angle and intensity of light within a specific wavelength range can be controlled, thereby achieving the adjustment of light transmittance.

[0038] The optical characteristics of the microlens array are as follows: The microlens array is composed of multiple tiny lenses, each of which has the ability to focus or disperse light. By adjusting the focal length, diameter, and arrangement of the microlenses, the propagation direction and energy distribution of light can be changed. For example, designing the microlens array into a focusing structure can improve the absorption efficiency of photovoltaic cells for light in a specific direction; while designing it into a dispersed structure can increase the scattering of light and improve the energy collection capacity of the photothermal system.

[0039] The preparation method of microstructures such as periodic gratings and microlens arrays is as follows:

[0040] 1) Electron beam lithography: Electron beam lithography is a high-precision nano-processing technology that can produce nano-scale periodic gratings or microlens arrays on the surface of perovskite cells. This technology first requires the design of the pattern of the optical microstructure, then the use of an electron beam to expose the photoresist, and finally the transfer of the pattern to the surface of the perovskite cell through processes such as development and etching.

[0041] 2) Nanoimprinting: Nanoimprinting technology is an efficient nano-processing method suitable for large-scale production of optical microstructures. This technology works by imprinting a mold with an optical microstructure pattern on a polymer film on the surface of the perovskite cell, and then replicating the pattern to the surface of the perovskite cell through processes such as curing or etching.

[0042] 3) Surfactant self-assembly: Surfactant molecules can self-assemble into ordered structures in solution. This property can be used to introduce optical microstructures during the growth of perovskite crystals. For example, by adding specific surfactants to the perovskite precursor solution, they can self-assemble into periodic microstructures during the crystal growth process, thereby achieving dynamic control of transmittance.

[0043] 4) Polymer self-assembly: Polymer molecules can also form structures with specific optical properties through self-assembly. By selecting appropriate polymer materials and self-assembly conditions, microlens arrays or other optical microstructures can be formed inside perovskite cells to improve the performance and stability of photovoltaic cells.

[0044] The above-mentioned controllable light transmittance structure is particularly suitable for areas with large seasonal light changes, such as high latitudes or areas with changeable climates. In these areas, light intensity and spectral distribution will change significantly with the change of seasons. The controllable light transmittance structure design can effectively cope with such changes and improve the stability and reliability of photovoltaic and solar thermal systems. In addition, the design is also suitable for places with high requirements for comprehensive energy utilization.

[0045] (ii) Photothermal reflector

[0046] The photothermal reflector is located below the semi-transparent photovoltaic cell, and is mainly used to reflect the remaining spectrum (including near-infrared light of 800-1200nm and infrared light greater than 1200nm) that is not absorbed by the semi-transparent photovoltaic cell, and transmit it directionally to subsequent components. The reflector can use a high-reflectivity metal as a substrate, and the surface is coated with a multi-layer thin film structure, including but not limited to an anti-reflection layer, a protective layer, a functional layer, etc. In addition, microstructures or nano-gratings can be selectively added to enhance the optical performance and ensure efficient reflection and directional control of light. The optimized mirror can be combined with a spectral divider to perform preliminary separation of the spectrum through the principle of thin film interference to ensure efficient utilization of light energy in different bands. The reflection peak of the photothermal reflector can be located at 800-1200nm.

[0047] Specifically, the photothermal reflector includes a metal coating and a dielectric stack disposed on the surface of the metal coating; each layer is specifically as follows:

[0048] Metal coating: The material can be made of high-reflectivity metal (such as silver, aluminum), prepared by magnetron sputtering or evaporation process, and the thickness is controlled at 100-300nm.

[0049] Dielectric stack: including multiple layers of SiO2 layers and TiO2 layers alternately stacked, SiO2 and TiO2 multilayer films are deposited by electron beam evaporation or sputtering, and the film thickness is designed so that the reflection peak is located at 800-1200nm; specifically, the single layer thickness of the SiO2 layer is 50-200nm, and the number of layers is 3-8; the single layer thickness of the TiO2 layer is 30-120nm, and the number of layers is 3-8.

[0050] Mirror molding: Use high-precision molding technology to produce a reflective surface with uniform curvature, with a surface roughness (Ra) less than 10nm, to enhance optical performance.

[0051] There is no strict restriction on the coupling connection method between the semi-transparent photovoltaic cell and the photothermal reflector. For example, the semi-transparent photovoltaic cell can be attached to the surface of the photothermal reflector by gluing, vacuum compaction, snap-on method, etc. In addition, a high thermal conductivity insulating layer (such as an alumina ceramic sheet) can be added between the semi-transparent photovoltaic cell and the photothermal reflector to improve the heat dissipation performance.

[0052] (III) Spectral divider

[0053] The spectrum divider is mainly used to accurately divide the near-infrared light of 800-1200nm and the far-infrared light greater than 1200nm in the remaining spectrum to achieve spectral separation, thereby reflecting the medium-wavelength light for photovoltaic power generation and transmitting the long-wavelength light for photothermal utilization.

[0054] The working principle of the spectrum divider is as follows: The core function of the spectrum divider is to selectively separate the wavelength of incident light through optical principles. The spectrum divider is usually composed of multiple layers of dielectric films. Through the difference in refractive index of different materials and the design of film thickness, the interference effect is used to reflect or transmit light of specific wavelengths; among them, medium-wavelength light (near-infrared light, 800-1200nm) is reflected to opaque photovoltaic cells, and long-wavelength light (far-infrared light, greater than 1200nm) is transmitted to the solar thermal collector for thermal power generation.

[0055] The structure design of the spectrum divider is as follows:

[0056] 1) Multilayer dielectric thin film divider: It is composed of multiple layers of high refractive index and low refractive index materials stacked alternately, and the thickness is precisely controlled to the nanometer level; this structure has high spectral separation accuracy and can be designed and optimized for specific bands.

[0057] 2) Grating type frequency divider: It is composed of regularly arranged microstructured gratings and realizes spectral separation through diffraction effect. It can directionally diffract light of different wavelengths. It is complex to prepare and is suitable for special optical path design and systems with high requirements on the direction of the optical path.

[0058] 3) Thin film-grating composite frequency divider: Combining the principles of thin film interference and grating diffraction, it integrates multiple spectroscopic functions; it has both the high precision of thin films and the flexibility of gratings; it can adapt to complex spectral and optical path requirements, and is suitable for high-performance systems with multi-band separation requirements.

[0059] The material selection of the spectrum divider is as follows:

[0060] 1) High refractive index materials: TiO2 (titanium oxide), Ta2O5 (tantalum pentoxide), etc. can be used to enhance the reflectivity of specific wavelengths.

[0061] 2) Low refractive index materials: SiO2 (silicon oxide), MgF2 (magnesium fluoride), etc. can be used to form optical contrast;

[0062] 3) Substrate material: glass, quartz, polymer, etc., which are required to have high light transmittance and thermal stability.

[0063] Coating technology can use methods such as electron beam evaporation, sputtering or chemical vapor deposition (CVD) to ensure film thickness uniformity and material adhesion.

[0064] The performance parameters of the spectrum divider are as follows:

[0065] 1) The separation and utilization efficiency of light energy in each band is usually required to reach more than 90%.

[0066] 2) The separation accuracy of the spectral divider for the target wavelength range determines its performance in adapting to different batteries and collectors; for different bands, the transmittance and reflectivity should be optimized to avoid energy loss.

[0067] 3) The performance needs to remain stable in high temperature and thermal environment.

[0068] The application characteristics of the spectrum divider are as follows:

[0069] 1) Efficient spectrum utilization: The spectrum divider accurately distributes light of different wavelengths to suitable components (such as photovoltaic cells and solar thermal collectors), greatly improving the overall energy utilization efficiency of the system.

[0070] 2) Flexible integration: It can be flexibly combined with solar thermal reflectors and photovoltaic cells through fixed brackets, embedded frames or slide rails, and can be adapted to different types of solar thermal power stations (such as tower, trough, dish, Fresnel, etc.).

[0071] 3) Optimize system design: The spectral splitter's light splitting characteristics can be adjusted according to specific needs, for example, by dynamically adjusting the angle to optimize the energy distribution path in conjunction with the solar incident angle.

[0072] In the photovoltaic-thermal coupling system, the spectral divider plays a key bridging role. It determines the distribution ratio of light energy in the photovoltaic and thermal systems, improves the accuracy of energy utilization in different light bands, and provides important technical support for the performance optimization of the entire system.

[0073] Specifically, the spectrum divider includes a substrate and a dielectric film layer arranged on the surface of the substrate, and each layer is specifically as follows:

[0074] Substrate: High temperature resistant quartz glass or borosilicate glass can be used.

[0075] Dielectric film layer: includes multiple layers of high refractive index material layers and low refractive index material layers alternately stacked, such as a multilayer dielectric film design of TiO2 / SiO2, with a reflection peak controlled at 400-750nm and a transmittance greater than 80% (wavelength range 800-1200nm); specifically, the single layer thickness of the high refractive index material layer is 30-300nm, and the number of layers is 5-25; the single layer thickness of the low refractive index material layer is 50-500nm, and the number of layers is 5-25.

[0076] Preparation process: Multilayer films can be prepared by electron beam evaporation or ion beam assisted deposition, and the thickness of each layer can be precisely controlled; in addition, the surface can be treated with hydrophobic and oleophobic treatment to improve anti-pollution capabilities.

[0077] The spectrum divider can be fixed at the front end of the photothermal reflector and supported by a precision frame to keep it parallel to the surface of the photothermal reflector.

[0078] Furthermore, the spectrum divider can be combined with smart materials to prepare an intelligent adaptive spectrum divider. The selection and characteristics of the smart materials are as follows:

[0079] 1) Shape memory alloy:

[0080] Material properties: Shape memory alloys have shape memory effect and superelasticity. They can return to a preset shape at a specific temperature and can produce reversible deformation within a certain range. This property allows them to be used to adjust the structure of the spectrum divider, thereby changing its optical properties.

[0081] Applicable scenarios: For environments with large changes in light intensity and temperature, shape memory alloys can automatically adjust the film thickness or grating structure of the spectrum divider according to temperature changes. For example, in a high temperature environment, the shape memory alloy shrinks, making the film thinner or the grating spacing smaller, thereby optimizing the separation efficiency of light in a specific band.

[0082] 2) Electrochromic materials:

[0083] Material properties: The optical properties of electrochromic materials can be changed by applying an electric field. Under different electric fields, electrochromic materials can show different colors and transparencies, thereby achieving control over the absorption, reflection and transmission of light.

[0084] Applicable scenarios: Electrochromic materials can be used to make adjustable spectroscopic films or gratings. By applying different electric fields, the optical properties of electrochromic materials can be changed, thereby achieving accurate separation and distribution of light in different bands. For example, when the light intensity is high, applying a higher electric field will enhance the absorption and reflection properties of the electrochromic material, thereby optimizing the light separation efficiency.

[0085] The preparation method of the intelligent adaptive crossover is as follows:

[0086] 1) Preparation of shape memory alloy divider:

[0087] Material preparation: Select appropriate shape memory alloy materials, such as nickel-titanium alloy (NiTi), etc. According to the design requirements, the shape memory alloy is processed into the required shape, such as film, spring, etc.

[0088] Preparation of spectroscopic film or grating: Physical vapor deposition (PVD), chemical vapor deposition (CVD) and other methods are used to prepare spectroscopic film or grating on the surface of shape memory alloy. The spectroscopic film can adopt a multi-layer dielectric film structure (i.e., dielectric film layer), and the separation of light of different wavelengths can be achieved by controlling the thickness and material composition of the film. The grating can be prepared by photolithography, nanoimprinting and other methods, and the diffraction and separation of light of different wavelengths can be achieved by controlling the period, depth and width of the grating and other parameters.

[0089] Integrated smart materials: Integrate the prepared spectroscopic film or grating with the shape memory alloy. The spectroscopic film or grating can be fixed on the surface of the shape memory alloy by gluing, welding, etc. At the same time, sensors and drive circuits are installed on the shape memory alloy to realize the deformation control of the shape memory alloy.

[0090] 2) Preparation of electrochromic material divider:

[0091] Material preparation: Select appropriate electrochromic materials, such as tungsten oxide (WO3), Prussian blue, etc. According to the design requirements, process the electrochromic materials into the required shapes, such as thin films, nanoparticles, etc.

[0092] Preparation of spectroscopic film or grating: Prepare electrochromic material film on substrate material by sol-gel method, spin coating method and other methods. The spectroscopic film can adopt multi-layer dielectric film structure (i.e. dielectric film layer), and the separation of light of different wavelengths can be achieved by controlling the thickness and material composition of the film. Grating can be prepared by photolithography, nanoimprinting and other methods, and the diffraction and separation of light of different wavelengths can be achieved by controlling the period, depth and width of the grating and other parameters.

[0093] Integrated smart materials: Integrate the prepared spectroscopic film or grating with the electrochromic material. The electrochromic material film can be covered on the surface of the spectroscopic film or grating by coating, deposition, etc. At the same time, sensors and drive circuits are installed on the electrochromic material to achieve electric field control of the electrochromic material.

[0094] Through the above optimization method, the intelligent adaptive crossover can better adapt to different light intensity and temperature conditions, realize the precise separation and distribution of light in different bands, and improve the adaptability and stability of the system.

[0095] (IV) Opaque photovoltaic cells

[0096] Opaque photovoltaic cells are mainly used to absorb near-infrared light in the 800-1200nm band and convert it into electrical energy. They can be made of materials such as crystalline silicon cells and GaAs cells. Opaque photovoltaic cells are installed downstream of the photothermal reflector and use near-infrared light transmitted directionally by the spectrum divider to generate electricity. Thermal conductive materials or heat dissipation devices can be added to the back of optimized opaque photovoltaic cells to prevent overheating caused by high-intensity light and improve cell efficiency and life.

[0097] Specifically, the opaque photovoltaic cell includes a substrate and a surface passivation layer disposed on the surface of the substrate; the specific details of each layer are as follows:

[0098] Substrate: High-efficiency crystalline silicon cells (PERC, TOPCon, etc.) are used as the substrate, with an efficiency of more than 23%.

[0099] Surface passivation layer: hydrogenated silicon oxide (SiOx:H) is used and prepared by plasma enhanced chemical vapor deposition (PECVD) process, and the thickness is controlled at 5-15nm, for example, about 10nm.

[0100] Packaging method: Double-layer EVA packaging is used, and an anti-reflective coating (such as nano coating) is added to the outer layer to improve optical gain and mechanical protection performance.

[0101] The opaque photovoltaic cell can be arranged at the focal position of the near-infrared light reflected by the spectrum divider and fixed by an aluminum alloy bracket to ensure that the high-energy short-wave light reflected by the divider is received.

[0102] (V) Solar thermal collector

[0103] The photothermal collector is mainly used to absorb infrared light greater than 1200nm for photothermal power generation, and a conventional photothermal collector in the art can be used.

[0104] (VI) Coupling structure

[0105] 1) Coupling of semi-transparent photovoltaic cells and photothermal reflectors

[0106] The coupling method of semi-transparent photovoltaic cells and photothermal reflectors is as follows:

[0107] a) Tight fit:

[0108] Semi-transparent photovoltaic cells are directly fixed on the surface of the photothermal reflector to form an integrated component. The photothermal reflector transmits infrared light to the photothermal collector and reflects near-infrared light to the opaque photovoltaic cells. This design is suitable for tower and trough photothermal power stations and can greatly reduce system volume and light loss.

[0109] b) Spatial stratification:

[0110] Semi-transparent photovoltaic cells and photothermal reflectors are arranged in layers and fixed by transparent brackets, with a certain space between them to enhance the heat dissipation effect. Opaque photovoltaic cells are placed in the reflected light path of the photothermal reflector, and use the split near-infrared light to generate electricity. This structure is suitable for the optimization design of multi-functional systems and is easy to maintain and upgrade.

[0111] c) Adjustable angle type:

[0112] The opaque photovoltaic cells and the solar thermal reflectors are connected by mechanical brackets, which allow the angle between the components to be adjusted dynamically, so that the incident angle of light is always in the best state, which is especially suitable for dish-type solar thermal power stations. This design can also adjust the layout of components according to seasonal sunshine conditions to improve the overall utilization of light energy.

[0113] 2) The laminated structure of semi-transparent photovoltaic cells and photothermal reflectors coupled with opaque photovoltaic cells

[0114] The stacked structure of the semi-transparent photovoltaic cell and the photothermal reflector is coupled with the opaque photovoltaic cell as follows:

[0115] a) Laminated structure angle adjustment type:

[0116] In this structure, the opaque photovoltaic cells are fixed around the stacked structure of the semi-transparent photovoltaic cells and the photothermal reflector, and their specific distances are reasonably arranged according to the optical path design of the spectrum divider.

[0117] Dynamic adjustment of the spectrum divider: A spectrum divider is set above the stacked structure of semi-transparent photovoltaic cells and thermal reflectors. It can be adjusted according to the angle of reflected light to accurately guide near-infrared light to the surface of opaque photovoltaic cells, while directionally transmitting far-infrared light to the thermal collector.

[0118] Efficient light energy utilization: Through the above structural design, it can be ensured that near-infrared light is efficiently absorbed by opaque photovoltaic cells and converted into electrical energy, while far-infrared light is efficiently absorbed by solar thermal collectors for thermal power generation, achieving accurate distribution and efficient utilization of spectral energy.

[0119] b) Opaque photovoltaic cell structure angle adjustment type

[0120] In this structure, the angle of the spectrum divider remains unchanged, while the opaque photovoltaic cell is dynamically adjusted through the bottom adjustment device. An adjustment column is provided at the bottom of the opaque photovoltaic cell, which can adjust the receiving angle of the opaque photovoltaic cell according to the angle change of the photothermal reflector to accurately receive the near-infrared light reflected by the spectrum divider. The above design makes full use of the optical properties of the photothermal reflector and the reflection path characteristics of the spectrum divider to ensure that the system can adapt to different sunlight conditions and environmental changes, and improve the stability and flexibility of the overall performance.

[0121] c) Dual system regulation type

[0122] In the dual-system adjustment structure, both the spectrum divider and the opaque photovoltaic cell are designed as angle-adjustable components.

[0123] The spectral divider and the opaque photovoltaic cell are adjusted in coordination: the angle of the spectral divider is adjusted in real time by precision control equipment to optimize the reflection path of near-infrared light; at the same time, the angle of the opaque photovoltaic cell is adjusted by the bottom adjustment device to ensure that its efficiency in receiving light energy is maximized.

[0124] Through the bidirectional adjustment of the spectral divider and the opaque photovoltaic cell, the precise frequency division of infrared light (near infrared and far infrared) and the optimization of the energy transmission path can be achieved, so that the photovoltaic power generation and the solar thermal power generation can work together to give full play to the comprehensive performance of the system.

[0125] The above three coupling structure designs combine the functional relationship between the spectrum divider, opaque photovoltaic cells and photothermal reflectors through different adjustment mechanisms, and are respectively suitable for fixed installation, dynamic environment and high-precision energy utilization demand scenarios. The above design schemes greatly improve the flexibility and efficiency of solar energy utilization, and provide feasible technical paths and practical value for various types of solar thermal power stations such as tower, trough, dish, and Fresnel.

[0126] The working principle of the solar energy comprehensive utilization coupling structure of the present invention is as follows:

[0127] 1) Spectrum allocation

[0128] Sunlight first passes through the semi-transparent photovoltaic cell, where the light in the 200-800nm ​​band is absorbed and converted into electrical energy, while the unabsorbed light (mainly including near-infrared light in the 800-1200nm range and infrared light >1200nm) is transmitted to the photothermal reflector. The photothermal reflector reflects the near-infrared light to the opaque photovoltaic cell, which completes the photoelectric conversion of the near-infrared light. The photothermal reflector also transmits infrared light to the downstream photothermal collector, using the thermal energy of the infrared light for photothermal power generation.

[0129] 2) Multi-energy conversion

[0130] Photovoltaic and solar thermal power generation are used together. Semi-transparent photovoltaic cells process short-wave light, opaque photovoltaic cells are responsible for medium-wave light, and solar thermal reflectors guide long-wave light to solar thermal collectors, forming an efficient spectrum partition utilization system. The coupling structure can effectively utilize the full-band energy of sunlight and maximize the overall energy conversion efficiency. It can be applied to tower, trough, dish, Fresnel and other solar thermal power stations, providing customized design solutions for different scenarios.

[0131] The present invention realizes the high integration of solar energy utilization through the innovative design of spectrum separation technology and multi-component coupling structure, and provides a new direction for the development of new solar power generation systems. In the photovoltaic and thermal integrated system of the present invention, the photothermal reflector, semi-transparent photovoltaic cell, opaque photovoltaic cell and divider can be composed into modules, which are convenient for disassembly and replacement using standardized interface design. In addition, the infrared light transmitted by the photothermal reflector is focused on the tubular thermal energy receiver, and molten salt is used as the heat transfer medium to transport the heat energy to the heat storage unit through the molten salt circulation system.

[0132] The coupling structure debugging and optimization method of the present invention is as follows:

[0133] Alignment and debugging: Use a laser collimator to precisely adjust the spectrum divider and opaque photovoltaic cells to ensure that the light is focused at the designed position.

[0134] Performance optimization: Combine CFD simulation to optimize the thermodynamic flow field, reduce system heat loss, and increase the output power of photovoltaic cells through MPPT control.

[0135] The present invention also provides a method for preparing the above-mentioned solar energy comprehensive utilization coupling structure, comprising the following steps:

[0136] S1: Coupling a semi-transparent photovoltaic cell onto the surface of a photothermal reflector to form a laminated structure;

[0137] S2: arranging the spectrum divider at the front end of the stacked structure, and arranging the opaque photovoltaic cell and the photothermal collector at the focal position of the near-infrared light reflected by the spectrum divider and the focal position of the far-infrared light transmitted by the spectrum divider, respectively;

[0138] The angle of the laminated structure and / or the opaque photovoltaic cell is adjusted by a bracket.

[0139] The present invention also provides the application of the above-mentioned solar energy comprehensive utilization coupling structure in a tower-type solar thermal power station, a trough-type solar thermal power station, a dish-type solar thermal power station or a Fresnel-type solar thermal power station.

[0140] The implementation of the present invention has at least the following advantages:

[0141] 1. Efficient use of spectrum allocation

[0142] Through spectral frequency division technology, ultraviolet light and visible light in the range of 200-800nm ​​are used in semi-transparent photovoltaic cells, and the photoelectric conversion efficiency can reach 18-22%.

[0143] The unabsorbed 800-1200nm near-infrared light is directed to the opaque photovoltaic cell, and the photoelectric conversion efficiency can reach 20-25%.

[0144] Far-infrared light greater than 1200nm is directed to the photothermal collector through a spectrum divider, and the photothermal conversion efficiency can reach 70-80%.

[0145] 2. Improved overall system efficiency

[0146] The solar energy comprehensive utilization coupling structure can increase the comprehensive utilization efficiency of solar energy to 60-67%, far exceeding a single photovoltaic or solar thermal system.

[0147] Through the separation design of photovoltaic and photothermal, the energy of different bands of sunlight can be maximized and the loss caused by spectral overlap can be reduced.

[0148] 3. Modular design facilitates promotion

[0149] The close coupling of semi-transparent photovoltaic cells and photothermal reflectors is suitable for tower, trough, dish, Fresnel and other types of photothermal power stations. It can reduce system volume and light loss and has strong adaptability.

[0150] The bracket design allows for dynamic adjustment of the component angle so that the light incident angle is always at the optimal state, which can further increase the light energy utilization rate by about 5-10% in areas with high sunshine.

[0151] 4. Thermal management and reliability enhancement

[0152] By adding heat dissipation devices, the operating temperature of opaque photovoltaic cells can be controlled at 25-40°C, effectively preventing overheating problems and extending the battery life to more than 20 years.

[0153] The surface of the photothermal reflector can maintain its reflectivity above 95% through anti-reflection and protective coating design, thereby achieving strong resistance to UV aging to adapt to high temperature and high radiation environments.

[0154] 5. Support multiple technology integration

[0155] Through specific structural design and optimization, the semi-transparent photovoltaic cell has an absorption rate of more than 90% for ultraviolet light and visible light in the 200-800nm ​​band and a transmittance of infrared light greater than 800nm.

[0156] Through specific structural design and optimization, the photothermal reflector can ensure the directional transmission efficiency of near-infrared light and far-infrared light to reach more than 90%.

[0157] Through specific structural design and optimization, the spectral divider has a separation efficiency of over 85% for the target wavelength range, significantly improving the accuracy of light energy distribution.

[0158] 6. Economic and environmental benefits

[0159] Under the same area conditions, the power generation capacity of this solar energy comprehensive utilization coupling structure is 20-40% higher than that of a single photovoltaic system, and it reduces the additional land resources and equipment investment required for the separate construction of solar thermal and photovoltaic systems.

[0160] The solar energy comprehensive utilization coupling structure meets the sustainable development needs of green energy and can reduce carbon dioxide emissions by 50 tons per year (based on 1MW installed capacity). BRIEF DESCRIPTION OF THE DRAWINGS

[0161] 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.

[0162] Figure 1 It is a side view of the coupling structure for comprehensive utilization of solar energy;

[0163] Figure 2 This is a top view of the coupling structure for comprehensive utilization of solar energy.

[0164] Description of reference numerals:

[0165] 1: Semi-transparent photovoltaic cell; 2: Photothermal reflector; 3: Spectral divider; 4: Opaque photovoltaic cell; 5: Photothermal collector; 6, 7: Bracket; 8: Sunlight; 9: Infrared light; 10: Near-infrared light; 11: Far-infrared light; 12: Laminated structure. DETAILED DESCRIPTION

[0166] 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.

[0167] 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.

[0168] 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.

[0169] Example 1

[0170] Combination Figure 1 , Figure 2 As shown, the solar energy comprehensive utilization coupling structure of this embodiment includes a semi-transparent photovoltaic cell 1, a photothermal reflector 2, a spectrum divider 3, an opaque photovoltaic cell 4 and a photothermal collector 5. The semi-transparent photovoltaic cell 1 absorbs ultraviolet light and visible light of 200-800nm ​​in sunlight 8, the photothermal reflector 2 is located below the semi-transparent photovoltaic cell 1 and reflects the remaining spectrum (infrared light 9) not absorbed by the semi-transparent photovoltaic cell 1, and the spectrum divider 3 divides the near-infrared light 10 of 800-1200nm and the far-infrared light 11 greater than 1200nm in the remaining spectrum to the opaque photovoltaic cell 4 and the photothermal collector 5 respectively. The opaque photovoltaic cell 4 uses the near-infrared light 10 for photovoltaic power generation, and the photothermal collector 5 uses the far-infrared light 11 for photothermal power generation.

[0171] (1) Semi-transparent photovoltaic cells

[0172] The semi-transparent photovoltaic cell 1 is provided with a substrate, a first transparent conductive layer, a hole transport layer, a light absorption layer, an electron transport layer, a second transparent conductive layer and an encapsulation layer in order from bottom to top; the details of each layer are as follows:

[0173] Substrate: High-transparency flexible substrate is used, and the thickness of the substrate is 0.2mm.

[0174] First transparent conductive layer: ITO (indium tin oxide) was deposited on the substrate by radio frequency magnetron sputtering, and then heat treated at 150° C. for 10 minutes to obtain a first transparent conductive layer with a thickness of 150 nm and a transmittance higher than 90%.

[0175] Hole transport layer: Poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate was deposited on the first transparent conductive layer by solution spin coating, and then annealed at 80° C. for 10 min to obtain a hole transport layer with a thickness of 40 nm.

[0176] Light absorption layer: The perovskite precursor solution was coated on the hole transport layer by solution spin coating, and a uniform MAPbI3 perovskite film was formed by wet chemical deposition, which was then annealed at 100°C for 30 minutes to obtain a light absorption layer with a thickness of 500 nm.

[0177] Electron transport layer: [6,6]-phenyl-C61 -Methyl butyrate (C60) was deposited on the light absorbing layer and then annealed at 70°C for 10 min to obtain an electron transport layer with a thickness of 30 nm.

[0178] Second transparent conductive layer: ITO (indium tin oxide) was deposited on the electron transport layer by radio frequency magnetron sputtering, and then heat treated at 150° C. for 5 minutes to obtain a second transparent conductive layer with a thickness of 150 nm.

[0179] Encapsulation layer: Ethylene vinyl acetate (PEVA) was hot-pressed on the surface of the second transparent conductive layer in a vacuum by a lamination process at 120° C. for 10 minutes to obtain an encapsulation layer with a thickness of 200 μm.

[0180] The absorptivity of the semi-transparent photovoltaic cell 1 to ultraviolet light and visible light in the wavelength range of 200-800 nm is 90%, and the transmittance to infrared light greater than 800 nm is 90%.

[0181] (ii) Photothermal reflector

[0182] The photothermal reflector 2 includes a metal coating and a dielectric stack arranged on the surface of the metal coating; the specific details of each layer are as follows:

[0183] Metal coating: A reflective surface with uniform curvature is produced using high-precision molding technology, with a surface roughness (Ra) of less than 10nm. Subsequently, a vacuum evaporation process is used to evenly deposit a silver film on the reflective surface to form a metal coating with a thickness of 100nm.

[0184] Dielectric stack: SiO2 layers and TiO2 layers are alternately deposited on the surface of the metal coating by chemical vapor deposition. The single layer thickness of the SiO2 layer is 50nm, and the number of layers is 8; the single layer thickness of the TiO2 layer is 30nm, and the number of layers is 8, thus obtaining a SiO2 / TiO2 dielectric stack with a reflection peak at 800-1200nm.

[0185] The reflectivity of the above-mentioned photothermal reflector 2 to the near-infrared light 10 of 800-1200nm and the far-infrared light 11 greater than 1200nm is 96%.

[0186] (III) Spectral divider

[0187] The spectrum divider 3 includes a substrate and a dielectric film layer arranged on the surface of the substrate, and the details of each layer are as follows:

[0188] Substrate: High temperature resistant quartz glass is used.

[0189] Dielectric film layer: Ta2O5 layers and MgF2 layers are alternately deposited on the substrate by electron beam evaporation. The single layer thickness of the Ta2O5 layer is 30nm, and the number of layers is 25; the single layer thickness of the MgF2 layer is 50nm, and the number of layers is 25, to obtain a dielectric film layer with a reflection peak of 400-750nm.

[0190] The reflectivity of the spectrum divider 3 to the near-infrared light 10 of 800-1200 nm is 90%, and the transmittance to the far-infrared light 11 of more than 1200 nm is 85%.

[0191] (IV) Opaque photovoltaic cells

[0192] The opaque photovoltaic cell 4 includes a substrate and a surface passivation layer disposed on the surface of the substrate; the specific details of each layer are as follows:

[0193] Substrate: High-efficiency crystalline silicon cells (PERC) are used as the substrate, with an efficiency of over 23%.

[0194] Surface passivation layer: Hydrogenated silicon oxide (SiOx:H) is deposited on the surface of the substrate by a plasma enhanced chemical vapor deposition (PECVD) process to obtain a surface passivation layer with a thickness of about 10 nm.

[0195] (V) Solar thermal collector

[0196] The photothermal collector 5 is mainly used to absorb far-infrared light greater than 1200nm for photothermal power generation, and adopts conventional photothermal collectors in the art.

[0197] (VI) Coupling structure

[0198] 1) Coupling of semi-transparent photovoltaic cells and photothermal reflectors

[0199] The semi-transparent photovoltaic cell 1 is attached to the surface of the photothermal reflector 2 by an adhesive method, so as to form a laminated structure 12 of the semi-transparent photovoltaic cell 1 and the photothermal reflector 2 .

[0200] 2) The laminated structure of semi-transparent photovoltaic cells and photothermal reflectors coupled with opaque photovoltaic cells

[0201] The stacked structure 12 of the semi-transparent photovoltaic cell 1 and the photothermal reflector 2 and the opaque photovoltaic cell 4 are both set to be angle-adjustable. The angle of the stacked structure 12 of the semi-transparent photovoltaic cell 1 and the photothermal reflector 2 is adjusted by a bracket 6 set at the bottom, and the angle of the opaque photovoltaic cell 4 is adjusted by a bracket 7 set at the bottom.

[0202] After testing, in the solar energy comprehensive utilization coupling structure of this embodiment, the photoelectric conversion efficiency of the semi-transparent photovoltaic cell 1 is 20%, the photoelectric conversion efficiency of the opaque photovoltaic cell 4 is 25%, the photothermal conversion efficiency of the photothermal collector 5 is 80%, and the solar energy comprehensive utilization efficiency of the entire coupling system is 67%.

[0203] Example 2

[0204] The solar energy comprehensive utilization coupling structure of this embodiment is basically the same as that of Embodiment 1 except that the structures of the semi-transparent photovoltaic cell, the photothermal reflector, and the spectrum divider are different from those of Embodiment 1.

[0205] The structures of the semi-transparent photovoltaic cell, photothermal reflector, and spectrum divider of this embodiment are as follows:

[0206] (1) Semi-transparent photovoltaic cells

[0207] The semi-transparent photovoltaic cell is provided with a substrate, a first transparent conductive layer, a hole transport layer, a light absorption layer, an electron transport layer, a second transparent conductive layer and an encapsulation layer from bottom to top; the details of each layer are as follows:

[0208] Substrate: High-transparency flexible substrate is used, and the thickness of the substrate is 2mm.

[0209] First transparent conductive layer: ITO (indium tin oxide) was deposited on the substrate by radio frequency magnetron sputtering, and then heat-treated at 150° C. for 10 minutes to obtain a first transparent conductive layer with a thickness of 300 nm.

[0210] Hole transport layer: Poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate was deposited on the first transparent conductive layer by solution spin coating, and then annealed at 80° C. for 10 min to prepare a hole transport layer with a thickness of 100 nm.

[0211] Light absorption layer: The perovskite precursor solution was coated on the hole transport layer by solution spin coating, and a uniform CsFA-MAPbBr3 (1:1) perovskite film was formed by wet chemical deposition, followed by annealing at 100°C for 30 minutes to obtain a 700nm light absorption layer.

[0212] Electron transport layer: [6,6]-phenyl-C 61 -Methyl butyrate (C60) was deposited on the light absorbing layer and then annealed at 70°C for 10 min to obtain an electron transport layer with a thickness of 100 nm.

[0213] Second transparent conductive layer: ITO (indium tin oxide) was deposited on the electron transport layer by radio frequency magnetron sputtering, and then heat treated at 150° C. for 5 minutes to obtain a second transparent conductive layer with a thickness of 300 nm.

[0214] Encapsulation layer: Ethylene vinyl acetate (PEVA) was hot-pressed on the surface of the second transparent conductive layer in a vacuum by a lamination process at 120° C. for 10 minutes to obtain an encapsulation layer with a thickness of 500 μm.

[0215] (ii) Photothermal reflector

[0216] The photothermal reflector includes a metal coating and a dielectric stack disposed on the surface of the metal coating; the specific details of each layer are as follows:

[0217] Metal coating: A reflective surface with uniform curvature is made using high-precision molding technology, with a surface roughness (Ra) of less than 10nm. Subsequently, a vacuum evaporation process is used to evenly deposit a silver film on the reflective surface to form a metal coating with a thickness of 300nm.

[0218] Dielectric stack: SiO2 layers and TiO2 layers are alternately deposited on the surface of the metal coating by chemical vapor deposition. The single layer thickness of the SiO2 layer is 200nm, and the number of layers is 3; the single layer thickness of the TiO2 layer is 120nm, and the number of layers is 3, thus obtaining a dielectric stack with a reflection peak at 800-1200nm.

[0219] (III) Spectral divider

[0220] The spectrum divider includes a substrate and a dielectric film layer arranged on the surface of the substrate, and the specific details of each layer are as follows:

[0221] Substrate: High temperature resistant quartz glass is used.

[0222] Dielectric film layer: TiO2 layers and SiO2 layers are alternately deposited on the substrate by electron beam evaporation. The single layer thickness of the TiO2 layer is 300nm, and the number of layers is 5; the single layer thickness of the SiO2 layer is 500nm, and the number of layers is 5, to obtain a dielectric film layer with a reflection peak of 400-750nm.

[0223] After testing, in the solar energy comprehensive utilization coupling structure of this embodiment, the photoelectric conversion efficiency of the semi-transparent photovoltaic cell is 18%, the photoelectric conversion efficiency of the opaque photovoltaic cell is 23%, the photothermal conversion efficiency of the photothermal collector is 78%, and the solar energy comprehensive utilization efficiency of the entire coupling system is 63%.

[0224] Example 3

[0225] This embodiment optimizes the light absorption layer of Embodiment 1 by introducing quantum dots into the perovskite layer.

[0226] The preparation method of the light absorbing layer of this embodiment is as follows:

[0227] 1) Preparation of CdSe and other quantum dots

[0228] The precursor solution containing Cd ions and Se ions (concentration of 0.5 mol / L) was placed in a high-pressure reactor and reacted for 2 hours at a temperature of 150°C and a pressure of 15 MPa to produce CdSe quantum dots with a size of about 5 nm.

[0229] 2) Preparation of perovskite layer

[0230] The CdSe quantum dots prepared above are dispersed in a solvent, and then mixed evenly with the perovskite precursor solution of Example 1 to obtain a mixed solution.

[0231] The mixed solution was coated on the hole transport layer by solution spin coating, and a uniform quantum dot-perovskite film (CdSe-MAPbI3) was formed by wet chemical deposition, followed by annealing at 100°C for 30 min to obtain a 500nm light absorption layer, in which the content of CdSe quantum dots was 3.5wt%.

[0232] After testing, the semi-transparent photovoltaic cell equipped with the perovskite layer with quantum dots introduced in this embodiment has an absorption rate of 93% for ultraviolet light and visible light in the 200-800nm ​​band, a transmittance of 95% for infrared light greater than 800nm, and a photoelectric conversion efficiency of 22%.

[0233] Comparative Example 1

[0234] This comparative example is basically the same as Example 1 except that the spectrum divider is not provided.

[0235] According to the test, in the solar energy comprehensive utilization coupling structure of this comparative example, the solar energy comprehensive utilization efficiency of the entire coupling system is 50%.

[0236] Comparative Example 2

[0237] Except that the SiO2 dielectric layer is used to replace the SiO2 / TiO2 dielectric stack in the photothermal reflector, the rest is basically the same as Example 1.

[0238] The SiO2 dielectric layer of this comparative example is deposited on the surface of the metal coating by chemical vapor deposition, and the thickness of the SiO2 layer is 640nm.

[0239] The reflectivity of the photothermal reflector in this comparative example to near-infrared light of 800-1200nm and far-infrared light greater than 1200nm is 85%.

[0240] Comparative Example 3

[0241] Except that the SiO2 / TiO2 dielectric stack is replaced by the TiO2 dielectric layer in the photothermal reflector, the rest is basically the same as Example 1.

[0242] The TiO2 dielectric layer of this comparative example is deposited on the surface of the metal coating by chemical vapor deposition, and the thickness of the TiO2 layer is 640nm.

[0243] The reflectivity of the photothermal reflector of this comparative example to near-infrared light of 800-1200nm and far-infrared light greater than 1200nm is 88%.

[0244] Comparative Example 4

[0245] Except for the different structure of the dielectric stack in the photothermal reflector, the rest is basically the same as Example 1.

[0246] The dielectric stack of this control example uses chemical vapor deposition to deposit SiO2 layers and TiO2 layers on the surface of the metal coating in sequence. The thickness of the SiO2 layer is 400nm, and the number of layers is only 1; the thickness of the TiO2 layer is 240nm, and the number of layers is only 1.

[0247] The reflectivity of the photothermal reflector in this reference example to near-infrared light of 800-1200nm and far-infrared light greater than 1200nm is 75%; in the solar energy comprehensive utilization coupling structure of this reference example, the photoelectric conversion efficiency of the opaque photovoltaic cell is 18%, the photothermal conversion efficiency of the photothermal collector is 75%, and the solar energy comprehensive utilization efficiency of the entire coupling system is 58%.

[0248] Comparative Example 5

[0249] Except for the different structure of the dielectric film layer in the spectrum divider, the rest is basically the same as that of Example 1.

[0250] The dielectric film layer of this control example is deposited on the substrate by electron beam evaporation in sequence by TiO2 layer and SiO2 layer, the single layer thickness of the TiO2 layer is 750nm, and the number of layers is only 1; the single layer thickness of the SiO2 layer is 1250nm, and the number of layers is only 1.

[0251] The reflectivity of the spectrum divider of this reference example to near-infrared light of 800-1200nm is 80%, and the transmittance to far-infrared light greater than 1200nm is 80%; in the solar energy comprehensive utilization coupling structure of this reference example, the solar energy comprehensive utilization efficiency of the entire coupling system is 56%.

[0252] 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 solar energy comprehensive utilization coupling structure, characterized in that: It includes a semi-transparent photovoltaic cell, a photothermal reflector, a spectrum divider, an opaque photovoltaic cell and a photothermal collector. The semi-transparent photovoltaic cell absorbs ultraviolet light and visible light in the solar spectrum. The photothermal reflector is located below the semi-transparent photovoltaic cell and reflects the remaining spectrum that is not absorbed by the semi-transparent photovoltaic cell. The spectrum divider divides the near-infrared light and far-infrared light in the remaining spectrum to the opaque photovoltaic cell and the photothermal collector respectively. The opaque photovoltaic cell uses near-infrared light for photovoltaic power generation, and the photothermal collector uses far-infrared light for photothermal power generation.

2. The solar energy comprehensive utilization coupling structure according to claim 1 is characterized in that: Semi-transparent photovoltaic cells absorb ultraviolet and visible light in the solar spectrum from 200-800nm; Preferably, the semi-transparent photovoltaic cell is provided with a substrate, a first transparent conductive layer, a first transmission layer, a light absorption layer, a second transmission layer, a second transparent conductive layer and an encapsulation layer in order from bottom to top; wherein the first transmission layer and the second transmission layer are hole transmission layers or electron transmission layers; Preferably, the light absorbing layer is a perovskite layer; the thickness of the light absorbing layer is 300-700 nm; Preferably, the preparation method of the perovskite layer comprises: mixing a solution containing quantum dots or photosensitive materials with a perovskite precursor solution and depositing the mixture on a substrate to form a quantum dot-perovskite or photosensitive-perovskite layer; the mass content of the quantum dots or photosensitive materials in the quantum dot-perovskite or photosensitive-perovskite layer is 3-4%.

3. The solar energy comprehensive utilization coupling structure according to claim 1 is characterized in that: The reflection peak of the photothermal reflector is located at 800-1200nm; Preferably, the photothermal reflector comprises a metal coating and a dielectric stack arranged on the surface of the metal coating. Preferably, the dielectric stack comprises a plurality of SiO2 layers and TiO2 layers alternately stacked; Preferably, the single layer thickness of the SiO2 layer is 50-200 nm, and the number of layers is 3-8; the single layer thickness of the TiO2 layer is 30-120 nm, and the number of layers is 3-8.

4. The solar energy comprehensive utilization coupling structure according to claim 1 is characterized in that: The spectrum divider divides the near infrared light of 800-1200nm and the far infrared light greater than 1200nm in the remaining spectrum; Preferably, the spectrum divider comprises a substrate and a dielectric film layer arranged on the surface of the substrate, and the dielectric film layer comprises a plurality of high refractive index material layers and low refractive index material layers alternately stacked; Preferably, the directional accuracy of the spectrum divider is greater than 80%.

5. The solar energy comprehensive utilization coupling structure according to claim 4 is characterized in that: The high refractive index material is selected from at least one of TiO2 and Ta2O5; the low refractive index material is selected from at least one of SiO2 and MgF2; Preferably, the single layer thickness of the high refractive index material layer is 30-300 nm, and the number of layers is 5-25; the single layer thickness of the low refractive index material layer is 50-500 nm, and the number of layers is 5-25.

6. The solar energy comprehensive utilization coupling structure according to claim 1 is characterized in that: Opaque photovoltaic cells absorb near-infrared light of 800-1200nm for photovoltaic power generation; Preferably, the opaque photovoltaic cell comprises a substrate and a surface passivation layer disposed on a surface of the substrate; Preferably, the substrate adopts a high-efficiency crystalline silicon cell; the efficiency of the high-efficiency crystalline silicon cell is >23%; Preferably, the material of the surface passivation layer is hydrogenated silicon oxide; the thickness of the surface passivation layer is 5-15 nm.

7. The solar energy comprehensive utilization coupling structure according to claim 1 is characterized in that: Solar thermal collectors absorb far-infrared light greater than 1200nm to generate solar thermal power.

8. The method for preparing the solar energy comprehensive utilization coupling structure according to any one of claims 1 to 7, characterized in that: The steps include: S1: Coupling a semi-transparent photovoltaic cell onto the surface of a photothermal reflector to form a laminated structure; S2: Arrange the spectrum divider at the front end of the stacked structure, and arrange the opaque photovoltaic cell and the photothermal collector at the focal position of the near-infrared light reflected by the spectrum divider and the focal position of the far-infrared light transmitted by the spectrum divider, respectively.

9. The preparation method according to claim 8, characterized in that: The angle of the laminated structure and / or the opaque photovoltaic cell is adjusted by a bracket.

10. Application of the solar energy comprehensive utilization coupling structure described in any one of claims 1 to 7 in a tower-type solar thermal power station, a trough-type solar thermal power station, a dish-type solar thermal power station or a Fresnel-type solar thermal power station.

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