Preparation and application of sandwich type solar concentrator based on photonic crystal

Abstract

This invention provides a sandwich-type fluorescent solar collector based on photonic crystals and its preparation method. Its structural feature is a sandwich structure, with the upper and lower layers being commercial optical glass and the middle layer being a polymer photonic crystal containing quantum dots. The preparation method includes the following steps: (1) Preparation of photonic crystal suspension containing quantum dots: First, a certain amount of ethanol solution of quantum dots (including carbon quantum dots, perovskite quantum dots or inorganic semiconductor quantum dots) is mixed with hydroxyethyl methacrylate and the ethanol is completely evaporated; Second, a certain amount of ethanol solution of monodisperse colloidal particles (including polymer colloids or silica colloids) is mixed with the above-mentioned hydroxyethyl methacrylate containing quantum dots, and after the ethanol is completely evaporated, a photonic crystal suspension containing quantum dots is obtained. (2) Preparation of polymer photonic crystal fluorescent solar collector based on quantum dots: First, a certain amount of photoinitiator and crosslinking agent are added to the above-mentioned photonic crystal suspension and mixed evenly; Second, a certain amount of the above-mentioned photonic crystal suspension is sandwiched between two optical glass plates and photopolymerized under ultraviolet light. After complete polymerization, the product is obtained. The fluorescent solar collector prepared by this invention is simple to manufacture, low in cost, highly transparent, stable, and has high light collection efficiency.

Description

Technical Field

[0001] This invention relates to the fabrication of a sandwich-type fluorescent solar collector based on photonic crystals, and particularly to the application of this photovoltaic device in photovoltaic integrated buildings such as photovoltaic glass and photovoltaic roofs. Background Technology

[0002] To mitigate the energy crisis and promote carbon peaking and carbon neutrality, developing Building Integrated Photovoltaics (BIPV), which combines photovoltaic power generation with green buildings, has become one of the main strategies for achieving these goals. Building rooftops, windows, and walls are ideal application scenarios for distributed photovoltaic systems. Currently, BIPV development relies heavily on the large-scale use of expensive commercial crystalline silicon solar cells, resulting in high costs and limited application only on rooftops, leading to low utilization rates. To reduce costs and expand the usable area, fluorescent solar collectors are one effective way to address these issues.

[0003] A fluorescent solar concentrator (LSC) is a light management device used for collecting, transmitting, and converting sunlight, offering great potential for realizing low-cost building-integrated photovoltaics (BIPV) windows. Typically, an LSC consists of a transparent waveguide (such as a polymer or glass substrate) and various types of luminescent materials (such as dyes, quantum dots, etc.) coated or embedded on the waveguide. Based on the total internal reflection of the substrate, after the luminescent material is excited, some of the re-emitted light is guided to the edge of the LSC and utilized by the connected solar cells. External optical efficiency (η) opt Light-collecting capacity (LCC) is a primary metric used to measure the light-collecting efficiency of fluorescent solar concentrators. Compared to traditional photovoltaic cells (such as semi-transparent solar cells), LSCs offer several advantages, including lower cost, ease of manufacturing and integration, transparency, flexibility in shape and configuration, the ability to add color, angle independence, and the use of diffused light. Currently, LSC structures include single-layer LSCs, multi-segment LSCs, and sandwich-structure LSCs. Relatively speaking, sandwich-structure LSCs offer more advantages, such as better protection of the internal light-emitting material from external environmental factors (such as oxygen and moisture), excellent long-term stability, and ease of integration with modern industrial windows.

[0004] The fabrication of high-efficiency solar collectors (LSCs) largely depends on how to collect and conduct more light from the LSC to the solar cells connected to its edge. Currently, most fluorescent solar collectors have low light-gathering efficiencies, making it difficult to meet the requirements of practical applications. Maintaining or enhancing the fluorescence emission intensity of the fluorescent material in the LSC is one of the most effective strategies. To achieve high-efficiency fluorescent solar collectors, there are currently two main strategies: one is to synthesize fluorescent materials with high quantum yields, such as perovskite quantum dots; however, their synthesis is complex, the quantum yield still decreases after mixing with polymer waveguides, they have poor long-term stability, and they are toxic and cause environmental pollution. The second strategy is to use back reflectors to improve sunlight collection efficiency; however, most back reflectors are made of opaque materials, such as silver mirrors, aluminum foil, and Bragg mirrors, thus affecting the practical application of LSCs in photovoltaic windows. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a sandwich-type fluorescent solar concentrator based on photonic crystals and its fabrication method. The aim is to improve the light collection efficiency of the fluorescent solar concentrator by introducing photonic crystals into it and utilizing the fluorescence enhancement effect of the photonic crystals. Furthermore, the sandwich structure of this fluorescent solar concentrator provides good protection for the fluorescent material within, and also facilitates long-term stability and integration into existing buildings.

[0006] Compared with traditional fluorescent solar collectors, this fluorescent solar collector has advantages such as high transparency, good stability, and high light collection efficiency.

[0007] To achieve the above objectives, the specific technical solution of the present invention is a sandwich-type fluorescent solar collector based on photonic crystal and its preparation method. Its structural feature is a sandwich structure, with the upper and lower layers being commercial optical glass and the middle layer being a polymer photonic crystal containing quantum dots.

[0008] The preparation method includes the following steps: (1) Preparation of quantum dot-based photonic crystal suspension: Monodisperse colloidal particles are synthesized, carbon quantum dots are prepared by solvothermal synthesis, ethanol solution of quantum dots is added to hydroxyethyl methacrylate monomer, and then ethanol is evaporated at a certain temperature to prepare quantum dot / hydroxyethyl methacrylate suspension. Then a certain amount of quantum dot / hydroxyethyl methacrylate suspension is co-assembled with monodisperse colloidal particles under evaporation drive to obtain the final product.

[0009] (2) Preparation of a polymer photonic crystal solar collector based on quantum dots: A certain amount of photoinitiator and crosslinking agent are added to the above photonic crystal suspension. After uniform mixing, a certain amount of the above mixed suspension is sandwiched between two transparent glass plates and photopolymerized under ultraviolet light to obtain the product.

[0010] In the above preparation method, in step (1), the monodisperse colloidal particles can be one of polystyrene, polymethyl methacrylate, or silica colloidal particles. In the above preparation method, in step (1), the size of the monodisperse colloidal particles is 150-220 nm. In the above preparation method, in step (1), the quantum dot can be one of carbon quantum dots, inorganic semiconductor quantum dots, or perovskite quantum dots. In the above preparation method, in step (1), the volume ratio of the quantum dot ethanol solution to the hydroxyethyl methacrylate monomer is 1:2 to 1:5. In the above preparation method, in step (1), the evaporation temperature is 20–100 °C. In the above preparation method, in step (1), the evaporation time is 0.5 to 2 hours. In the above preparation method, in step (1), the volume ratio of the quantum dot / hydroxyethyl methacrylate suspension to the monodisperse colloidal particles is 1:1 to 1:5. In the above preparation method, in step (2), the amount of suspension used is 100 μL to 5 mL. Compared with the prior art, the above-described technical solutions conceived in this invention can achieve the following beneficial effects: 1) This invention directly co-assembles quantum dots and monodisperse colloidal particles using a solvent evaporation-induced assembly method to obtain a photonic crystal suspension. The preparation is simple, with low viscosity and good fluidity, and it is compatible with various large-area industrial film-forming technologies, such as blade coating, drop coating, and inkjet printing.

[0011] 2) This invention introduces fluorescent quantum dots into polymer photonic crystals without affecting the transparency of polymer photonic crystal solar collectors. In addition, the collectors can exhibit vibrant structural colors under strong light.

[0012] 3) Compared with traditional fluorescent solar collectors, this invention introduces photonic crystals into fluorescent solar collectors and utilizes the fluorescence enhancement effect of photonic crystals to improve the light collection efficiency of fluorescent solar collectors.

[0013] In summary, compared with existing technologies, the above-described technical solutions conceived in this invention can achieve beneficial effects such as simple preparation, low cost, high transparency, good stability, and high light collection efficiency.

[0014] Instruction manual illustrations Figure 1: Schematic diagram of a sandwich-type fluorescent solar collector based on photonic crystals Figure 2: Optical images of the sandwich-type fluorescent solar collector based on photonic crystal under ambient light (AC), simulated sunlight (DF), and ultraviolet light (GH). Figure 3: SEM image of the colloidal particle-quantum dot polymer layer Figure 4: Fluorescence spectra of the sandwich-type fluorescent solar collector based on photonic crystal and the control LSC without photonic crystal at a quantum dot concentration of 0.1 wt%. Figure 5: Performance bar chart of sandwich-type fluorescent solar concentrator based on photonic crystal compared to control LSC without photonic crystal. Specific Implementation Cases The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. It is to be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0015] Example 1 (1) An ethanol solution with red carbon dots was prepared by a solvothermal synthesis method. Specifically, 0.01 g of p-phenylenediamine and 0.03 g of lignin were dissolved in 10 mL of ethanol and solvothermal at 200 °C. Correspondingly, the ethanol solutions with green and yellow carbon dots were prepared by replacing p-phenylenediamine with o-phenylenediamine and m-phenylenediamine, respectively.

[0016] (2) Monodisperse poly(methyl methacrylate-N-isopropylacrylamide) colloidal particles were synthesized by a modified emulsion polymerization method without emulsifiers under boiling conditions. Specifically, 0.04 g of sodium chloride and 160 mL of deionized water were added to a 500 mL three-necked flask with stirring. After the sodium chloride was completely dissolved, 3.5 mL of methyl methacrylate, 0.17 g of N-isopropylacrylamide as monomers, and 0.25 mL of divinylbenzene as a crosslinking agent were added to the solution. The mixture was heated to 110 °C for 20 min, and then 5 mL of ammonium persulfate solution was injected. The system was then refluxed and stirred at boiling for 3 hours. The poly(methyl methacrylate-N-isopropylacrylamide) colloidal particles were washed by repeated centrifugation for 25 min and sonication for 30 min three times. Finally, the colloidal particles were further cleaned by dialysis with deionized water and ion exchange resin.

[0017] (3) A carbon dot-hydroxyethyl methacrylate suspension with a carbon dot content of 0.1 wt% was prepared by adding 1 mL of carbon dot ethanol solution to 1 mL of hydroxyethyl methacrylate monomer and then evaporating the ethanol at 60°C for 10 hours. 6 g of monodisperse poly(methyl methacrylate-N-isopropylacrylamide) colloidal particle solution was taken, and 8 g of carbon dot-hydroxyethyl methacrylate solution was added. Then, ethanol was evaporated at 30°C for 24 hours to obtain a carbon dot-based colloidal crystal suspension with various iridescent colors. The carbon dot-based colloidal crystal suspension was prepared by co-assembling carbon dots and monodisperse poly(methyl methacrylate-N-isopropylacrylamide) colloid in hydroxyethyl methacrylate monomer via an evaporation-induced assembly method.

[0018] (4) First, 0.05 mL of photoinitiator and 0.05 mL of crosslinking agent were added to the carbon dot-based colloidal crystal suspension. 300 μL of the above suspension was dropped onto a transparent glass slide and cast, then covered with another glass slide. The above sandwich structure, with the carbon dot-based colloidal crystal suspension as the interlayer, was left to stand naturally at room temperature for 2 hours for further crystallization. Afterward, the sandwich structure was polymerized under 365 nm ultraviolet light for 2 minutes to obtain a carbon dot-based polymer photonic solar collector.

[0019] Example 2 (1) An ethanol solution with red carbon dots was prepared by a solvothermal synthesis method. Specifically, 0.01 g of p-phenylenediamine and 0.03 g of lignin were dissolved in 10 mL of ethanol and solvothermal at 200 °C. Correspondingly, the ethanol solutions with green and yellow carbon dots were prepared by replacing p-phenylenediamine with o-phenylenediamine and m-phenylenediamine, respectively.

[0020] (2) Place 85 mL of ethanol, 4 mL of ammonia (concentration 25%-28%) and 8 mL of deionized water in a 250 mL conical flask, and stir magnetically at 30 ℃ for 700 rpm. After the temperature stabilizes, add 3 mL of tetraethyl orthosilicate and stir for 15 minutes. After the solution turns milky white, adjust the stirring speed to 500 rpm and react at 30 ℃ for 6 hours. Then, centrifuge at 8000 rpm for 6 minutes and wash with ethanol as solvent 2-3 times to obtain silica microspheres with a particle size of 200-220 nm.

[0021] (3) A carbon dot-hydroxyethyl methacrylate suspension with a carbon dot content of 0.1 wt% was prepared by adding 1 mL of carbon dot ethanol solution to 1 mL of hydroxyethyl methacrylate monomer and then evaporating the ethanol at 60°C for 10 hours. 5 g of monodisperse silica microsphere solution was taken, and 7.5 g of carbon dot-hydroxyethyl methacrylate solution was added. Then, ethanol was evaporated at 30°C for 24 hours to obtain a carbon dot-based colloidal crystal suspension with various iridescent colors. The carbon dot-based colloidal crystal suspension was prepared by co-assembling carbon dots and monodisperse silica in hydroxyethyl methacrylate monomer via an evaporation-induced assembly method.

[0022] (4) First, 0.05 mL of photoinitiator and 0.05 mL of crosslinking agent were added to the carbon dot-based colloidal crystal suspension. 300 μL of the above suspension was dropped onto a transparent glass slide and cast, then covered with another optical glass slide. The above sandwich structure, with the carbon dot-based colloidal crystal suspension as the interlayer, was left to stand naturally at room temperature for 2 hours for further crystallization. Afterward, the sandwich structure was polymerized under 365 nm ultraviolet light for 2 minutes to obtain a carbon dot-based polymer photonic solar collector.

[0023] Example 3 (1) Monodisperse poly(methyl methacrylate-N-isopropylacrylamide) colloidal particles were synthesized by a modified emulsion polymerization method without emulsifiers under boiling conditions. Specifically, 0.04 g of sodium chloride and 160 mL of deionized water were added to a 500 mL three-necked flask with stirring. After the sodium chloride was completely dissolved, 3.5 mL of methyl methacrylate, 0.17 g of N-isopropylacrylamide as monomers, and 0.25 mL of divinylbenzene as a crosslinking agent were added to the solution. The mixture was heated to 110 °C for 20 min, and then 5 mL of ammonium persulfate solution was injected. The system was then refluxed and stirred at boiling for 3 hours. The poly(methyl methacrylate-N-isopropylacrylamide) colloidal particles were washed by repeated centrifugation for 25 min and sonication for 30 min three times. Finally, the colloidal particles were further cleaned by dialysis with deionized water and ion exchange resin.

[0024] (2) Using commercially available inorganic semiconductor quantum dots, 1 mL of inorganic semiconductor quantum dot ethanol solution was added to 1 mL of hydroxyethyl methacrylate monomer, and then the ethanol was evaporated at 60°C for 10 hours to prepare an inorganic semiconductor quantum dot-hydroxyethyl methacrylate suspension with an inorganic semiconductor quantum dot content of 0.1 wt%. 5 g of monodisperse poly(methyl methacrylate-N-isopropylacrylamide) colloidal particle solution was taken, and 7.5 g of inorganic semiconductor quantum dot-hydroxyethyl methacrylate solution was added. Then, the ethanol was evaporated at 30°C for 24 hours to obtain an inorganic semiconductor quantum dot-based colloidal crystal suspension with various iridescent colors. The inorganic semiconductor quantum dot-based colloidal crystal suspension was prepared by co-assembling inorganic semiconductor quantum dots and monodisperse poly(methyl methacrylate-N-isopropylacrylamide) colloidal particles in hydroxyethyl methacrylate monomer via an evaporation-induced assembly method.

[0025] (3) First, 0.05 mL of photoinitiator and 0.05 mL of crosslinking agent were added to the inorganic semiconductor quantum dot-based colloidal crystal suspension. 300 μL of the above suspension was dropped onto a transparent glass slide and cast, and then covered with another glass slide. The above sandwich structure, with the inorganic semiconductor quantum dot-based colloidal crystal suspension as the sandwich, was left to stand naturally at room temperature for 2 hours for further crystallization. Afterwards, the sandwich structure was polymerized under 365 nm ultraviolet light for 2 minutes to obtain a polymer photonic solar collector based on inorganic semiconductor quantum dots.

[0026] Example 4 (1) Monodisperse poly(methyl methacrylate-N-isopropylacrylamide) colloidal particles were synthesized by a modified emulsion polymerization method without emulsifiers under boiling conditions. Specifically, 0.04 g of sodium chloride and 160 mL of deionized water were added to a 500 mL three-necked flask with stirring. After the sodium chloride was completely dissolved, 3.5 mL of methyl methacrylate, 0.17 g of N-isopropylacrylamide as monomers, and 0.25 mL of divinylbenzene as a crosslinking agent were added to the solution. The mixture was heated to 110 °C for 20 min, and then 5 mL of ammonium persulfate solution was injected. The system was then refluxed and stirred at boiling for 3 hours. The poly(methyl methacrylate-N-isopropylacrylamide) colloidal particles were washed by repeated centrifugation for 25 min and sonication for 30 min three times. Finally, the colloidal particles were further cleaned by dialysis with deionized water and ion exchange resin.

[0027] (2) Using commercially available perovskite quantum dots, 1 mL of an ethanol solution of perovskite quantum dots was added to 1 mL of hydroxyethyl methacrylate monomer, and then the ethanol was evaporated at 60°C for 10 hours to prepare a perovskite quantum dot-hydroxyethyl methacrylate suspension with a perovskite quantum dot content of 0.1 wt%. 5 g of a monodisperse poly(methyl methacrylate-N-isopropylacrylamide) colloidal solution was taken, and 7.5 g of a perovskite quantum dot-hydroxyethyl methacrylate solution was added. Then, the ethanol was evaporated at 30°C for 24 hours to obtain a perovskite quantum dot-based colloidal crystal suspension with various iridescent colors. The perovskite quantum dot-based colloidal crystal suspension was prepared by co-assembling perovskite quantum dots and monodisperse poly(methyl methacrylate-N-isopropylacrylamide) colloidal particles in hydroxyethyl methacrylate monomer via an evaporation-induced assembly method.

[0028] (3) First, 0.05 mL of photoinitiator and 0.05 mL of crosslinking agent were added to the perovskite quantum dot-based colloidal crystal suspension. 300 μL of the above suspension was dropped onto a transparent glass slide and cast, then covered with another glass slide. The above sandwich structure, with the perovskite quantum dot-based colloidal crystal suspension as the interlayer, was left to stand naturally at room temperature for 2 hours for further crystallization. Afterward, the sandwich structure was polymerized under 365 nm ultraviolet light for 2 minutes to obtain a polymer photonic solar collector based on perovskite quantum dots.

[0029] Example 5 (1) Place 85 mL of ethanol, 4 mL of ammonia (concentration 25%-28%) and 8 mL of deionized water in a 250 mL conical flask, and stir magnetically at 30℃ for 700 rpm. After the temperature stabilizes, add 3 mL of tetraethyl orthosilicate and stir for 15 minutes. After the solution turns milky white, adjust the speed to 500 rpm and react at 30℃ for 6 hours. Then, centrifuge at 8000 rpm for 6 minutes and wash with ethanol as solvent 2-3 times to obtain silica microspheres with a particle size of 200-220 nm.

[0030] (2) Using commercially available inorganic semiconductor quantum dots, 1 mL of inorganic semiconductor quantum dot ethanol solution was added to 1 mL of hydroxyethyl methacrylate monomer, and then the ethanol was evaporated at 60°C for 10 hours to prepare an inorganic semiconductor quantum dot-hydroxyethyl methacrylate suspension with an inorganic semiconductor quantum dot content of 0.1 wt%. 5 g of monodisperse silica microsphere solution was taken, and 7.5 g of inorganic semiconductor quantum dot-hydroxyethyl methacrylate solution was added. Then, the ethanol was evaporated at 30°C for 24 hours to obtain an inorganic semiconductor quantum dot-based colloidal crystal suspension with various iridescent colors. The inorganic semiconductor quantum dot-based colloidal crystal suspension was prepared by co-assembling inorganic semiconductor quantum dots and monodisperse silica in hydroxyethyl methacrylate monomer via an evaporation-induced assembly method.

[0031] (3) First, 0.05 mL of photoinitiator and 0.05 mL of crosslinking agent were added to the inorganic semiconductor quantum dot-based colloidal crystal suspension. 300 μL of the above suspension was dropped onto a transparent glass slide and cast, then covered with another glass slide. The above sandwich structure, with the inorganic semiconductor quantum dot-based colloidal crystal suspension as the interlayer, was left to stand naturally at room temperature for 2 hours for further crystallization. Afterward, the sandwich structure was polymerized under 365 nm ultraviolet light for 2 minutes to obtain a polymer photonic solar collector based on inorganic semiconductor quantum dots.

[0032] Example 6 (1) Place 85 mL of ethanol, 4 mL of ammonia (concentration 25%-28%) and 8 mL of deionized water in a 250 mL conical flask, and stir magnetically at 30℃ for 700 rpm. After the temperature stabilizes, add 3 mL of tetraethyl orthosilicate and stir for 15 minutes. After the solution turns milky white, adjust the speed to 500 rpm and react at 30℃ for 6 hours. Then, centrifuge at 8000 rpm for 6 minutes and wash with ethanol as solvent 2-3 times to obtain silica microspheres with a particle size of 200-220 nm.

[0033] (2) Using commercially available perovskite quantum dots, 1 mL of perovskite quantum dot ethanol solution was added to 1 mL of hydroxyethyl methacrylate monomer, and then the ethanol was evaporated at 60°C for 10 hours to prepare a perovskite quantum dot-hydroxyethyl methacrylate suspension with a perovskite quantum dot content of 0.1 wt%. 5 g of monodisperse silica microsphere solution was taken, and 7.5 g of inorganic semiconductor quantum dot-hydroxyethyl methacrylate solution was added. Then, the ethanol was evaporated at 30°C for 24 hours to obtain a perovskite quantum dot-based colloidal crystal suspension with various iridescent colors. The perovskite quantum dot-based colloidal crystal suspension was prepared by co-assembling perovskite quantum dots and monodisperse silica in hydroxyethyl methacrylate monomer via an evaporation-induced assembly method.

[0034] (3) First, 0.05 mL of photoinitiator and 0.05 mL of crosslinking agent were added to the perovskite quantum dot-based colloidal crystal suspension. 300 μL of the above suspension was dropped onto a transparent glass slide and cast, then covered with another glass slide. The above sandwich structure, with the perovskite quantum dot-based colloidal crystal suspension as the interlayer, was left to stand naturally at room temperature for 2 hours for further crystallization. Afterward, the sandwich structure was polymerized under 365 nm ultraviolet light for 2 minutes to obtain a polymer photonic solar collector based on perovskite quantum dots.

Claims

1. A sandwich-type fluorescent solar collector based on photonic crystal, characterized by a sandwich structure, with the upper and lower layers being commercial optical glass and the middle layer being a polymer photonic crystal layer containing quantum dots; The method for preparing the sandwich-type fluorescent solar collector includes: (1) Preparation of quantum dot-based photonic crystal suspension: Monodisperse colloidal particles are synthesized, carbon quantum dots are prepared by solvothermal synthesis, ethanol solution of quantum dots is added to hydroxyethyl methacrylate monomer, and then ethanol is evaporated at a certain temperature to prepare quantum dot-hydroxyethyl methacrylate suspension. Then a certain amount of quantum dot-hydroxyethyl methacrylate suspension is co-assembled with monodisperse colloidal particles under evaporation drive to obtain the final product. (2) Preparation of a polymer photonic crystal solar collector based on quantum dots: A certain amount of photoinitiator and crosslinking agent are added to the above photonic crystal suspension. After uniform mixing, a certain amount of the mixed suspension is sandwiched between two transparent glass plates and photopolymerized under ultraviolet light to obtain the product.

2. A method for fabricating a sandwich-type fluorescent solar collector based on a photonic crystal, comprising the following steps: (1) Preparation of a photonic crystal suspension containing quantum dots: First, an ethanol solution of quantum dots is mixed with hydroxyethyl methacrylate and evaporated at 60°C for 10 hours to allow the ethanol to completely evaporate; the quantum dots are one of carbon quantum dots, inorganic semiconductor quantum dots, or perovskite quantum dots. Second, a certain amount of an ethanol solution of monodisperse colloidal particles is mixed with the above-mentioned hydroxyethyl methacrylate containing quantum dots; the monodisperse colloidal particles are one of polystyrene, polymethyl methacrylate, or silica gel; the ethanol solution of quantum dots is mixed with the hydroxyethyl methacrylate monomer. The volume ratio is 1:2 to 1:

5. After evaporating at 30°C for 24 hours to completely evaporate the ethanol, a photonic crystal suspension containing quantum dots is obtained. (2) Preparation of a polymer photonic crystal fluorescent solar collector based on quantum dots: 1-5% photoinitiator and 1-5% crosslinking agent are added to the above suspension. After mixing evenly, 100μL to 5mL of the above suspension is sandwiched between two transparent glass plates and photopolymerized under ultraviolet light for 2-5 minutes. The volume ratio of the quantum dot-hydroxyethyl methacrylate suspension to the monodisperse colloidal particles is 1:1 to 1:5.

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