Fluorescent particle induced transmittance radiation cooling film, preparation method and application thereof

Abstract

The application discloses a fluorescent particle induced ultra-transmittance radiation refrigeration film and a preparation method and application thereof. The preparation method comprises the following steps: uniformly mixing DCPDA monomers, graphene quantum dot dispersion liquid and an ultraviolet curing agent to obtain a mixed solution; concentrating the mixed solution to obtain a casting solution; coating the casting solution on the surface of a substrate to obtain a wet film; and curing the wet film to obtain the fluorescent particle induced ultra-transmittance radiation refrigeration film. By introducing the fluorescent particles into a polymer matrix and adding the ultraviolet curing agent, the fluorescent particle induced ultra-transmittance radiation refrigeration film is formed, the high transmittance of sunlight and the high infrared emissivity are realized, the radiation refrigeration performance of the fluorescent particle induced ultra-transmittance radiation refrigeration film is excellent, and the fluorescent particle induced ultra-transmittance radiation refrigeration film is suitable for building energy saving, photovoltaic cell cooling and cold chain transportation and the like. The preparation process is simple and suitable for large-scale application.

Description

Technical Field

[0001] This invention relates to the field of passive radiation cooling materials technology, and in particular to a fluorescent particle-induced supertransmittance radiation cooling thin film, its preparation method and application. Background Technology

[0002] Radiative cooling is a method of cooling that utilizes the radiation of heat from an object to an atmospheric window (8-13 μm). It is significant for alleviating energy consumption and reducing air conditioning load. However, most current radiative cooling materials require complex micro / nano structures or multilayer stacking, making their fabrication processes complex. Furthermore, the vast majority of radiative cooling materials are white, exhibiting poor visible light transmittance, which limits their application potential.

[0003] Therefore, the development of novel transparent radiation-cooling films with high light transmittance, high infrared emissivity, and ease of preparation has become an urgent need. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose a fluorescent particle-induced high-transmittance radiation-cooling thin film, its preparation method and application, thereby solving the technical problems of low visible light transmittance and complex preparation methods of radiation-cooling thin films in the prior art.

[0005] In a first aspect, the present invention provides a method for preparing a fluorescent particle-induced supertransmittance radiation-cooled thin film, comprising the following steps: S1. Mix DCPDA monomer, graphene quantum dot dispersion and UV curing agent evenly to obtain a mixture; S2. After the mixture is concentrated, the casting solution is obtained; S3. Apply the casting solution to the substrate surface to obtain a wet film; S4. The wet film is cured to obtain a fluorescent particle-induced supertransmittance radiation cooling film.

[0006] In a second aspect, the present invention provides a fluorescent particle-induced supertransmittance radiation-cooling film, which is obtained by the preparation method of the fluorescent particle-induced supertransmittance radiation-cooling film provided in the first aspect of the present invention.

[0007] Thirdly, the present invention provides an application of a fluorescent particle-induced supertransmittance radiation cooling film, which is used in fields such as building energy conservation, photovoltaic cell cooling, and cold chain transportation.

[0008] Compared with the prior art, the beneficial effects of the present invention include: This invention achieves a balance between high solar transmittance and high infrared emissivity by introducing fluorescent particles into a polymer matrix and adding an ultraviolet curing agent. The resulting fluorescent particle-induced supertransmittance radiative cooling film exhibits excellent radiative cooling performance and is suitable for applications such as building energy conservation, photovoltaic cell cooling, and cold chain transportation. The preparation process of this invention is simple and suitable for large-scale applications. Attached Figure Description

[0009] Figure 1 These are optical photographs of samples F-1, F-2, F-3, and E-8 under an incandescent lamp in Embodiment 1 of the present invention; from left to right in the figures, they are sample F-1, sample F-2, sample F-3, and sample E-8. Figure 2 This is a SEM image of the surface of sample F-2 in Example 1 of this invention; Figure 3 These are the visible light transmittance test graphs of samples F-4, F-5, and E-8 in Example 1 of this invention; Figure 4 These are optical photographs of samples F-4, F-5, and E-8 under ultraviolet light irradiation in Embodiment 1 of the present invention; from left to right in the figures, they are samples F-4, F-5, and E-8. Figure 5 These are FDTD simulation images of samples F-4 and E-8 in Embodiment 1 of the present invention; in the image, samples F-4 and E-8 are shown from left to right. Figure 6 These are test graphs of visible light transmittance and mid-infrared emissivity of the E-8 sample and commercial glass in Example 1 of this invention; Figure 7 This is a SEM image of the cross-section of sample E-8 in Embodiment 1 of the present invention; Figure 8 This is a schematic diagram of the solar panel packaging in Embodiment 2 of the present invention; Figure 9 The J / V curves are those of the small-area TTEG thin-film encapsulated solar panel prepared in Example 2 of the present invention and the glass encapsulated solar panel prepared in Comparative Example 1, when the backsheet temperature is 25°C. Figure 10 These are the cooling curves of the small-area TTEG thin-film encapsulated solar panel prepared in Example 2 of the present invention and the glass encapsulated solar panel prepared in Comparative Example 1. Figure 11 The J / V curve is measured when the backsheet temperature of the small-area TTEG thin-film encapsulated solar panel prepared in Example 2 of this invention is 9°C lower than the backsheet temperature of the glass encapsulated solar panel prepared in Comparative Example 1. Detailed Implementation

[0010] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0011] In a first aspect, the present invention provides a method for preparing a fluorescent particle-induced supertransmittance radiation-cooled thin film, comprising the following steps: S1. Mix DCPDA (tricyclodecanedimethylethanol diacrylate) monomer, graphene quantum dot dispersion and UV curing agent evenly to obtain a mixture; S2. After the mixture is concentrated, the casting solution is obtained; S3. Apply the casting solution to the substrate surface to obtain a wet film; S4. The wet film is cured to obtain a fluorescent particle-induced supertransmittance radiation cooling film.

[0012] In this embodiment, the mass fraction of the graphene quantum dot dispersion is 0.0005%~0.002%, and more specifically 0.0008%~0.0012%, and the solvent is an alcohol solvent.

[0013] In this embodiment, the preparation method of the graphene quantum dot dispersion includes: o-phenylenediamine (OPD) and a catalyst were dispersed in an alcohol solvent and then subjected to a solvothermal reaction to obtain a graphene quantum dot dispersion.

[0014] Preferably, the catalyst is at least one of oxalic acid and acetic acid; more preferably, it is oxalic acid.

[0015] Preferably, the mass ratio of OPD to catalyst is 1:(0.3~3), and more preferably 1:1.

[0016] Preferably, the alcohol solvent is at least one of methanol, ethanol, and ethylene glycol.

[0017] Preferably, the ratio of OPD to alcohol solvent is 0.1~0.3 mg: 1 mL.

[0018] Preferably, the dispersion is uniform by ultrasonication.

[0019] More preferably, the ultrasound time is 3 to 10 minutes.

[0020] Preferably, the temperature of the solvothermal reaction is 80~200℃, more preferably 120~180℃, the reaction time is 4~36h, more preferably 12~36h, and the heating rate is 5~10℃ / min, more preferably 8℃ / min.

[0021] In this embodiment, the mass ratio of DCPDA monomer to graphene quantum dot dispersion is 1:(0.5~5), including but not limited to 1:0.5, 1:1, 1:2, 1:3, 1:4, 1:5, etc., preferably 1:(1~2). If the amount of graphene quantum dot dispersion is too low, the visible light transmittance will not be sufficiently improved; if the amount of graphene quantum dot dispersion is too high, the visible light transmittance of the film will decrease significantly, and the light transmission gain brought by fluorescence will be far lower than its blocking strength on transmittance.

[0022] In this embodiment, the UV curing agent is ethyl 2,4,6-trimethylbenzoylphenylphosphonate (TPO-L).

[0023] In this embodiment, the mass ratio of DCPDA monomer to UV curing agent is 1:(0.02~0.045). If the amount of curing agent is too low, the surface curing will be incomplete; if the amount of curing agent is too high, the color of the film will darken, resulting in a decrease in visible light transmittance.

[0024] In this embodiment, the process of uniformly mixing DCPDA monomer, graphene quantum dot dispersion, and UV curing agent includes: stirring at 40~60 ℃ in the dark for 1~3 h, followed by ultrasonication at 40~60 ℃ in the dark for 1~3 h.

[0025] In this embodiment, concentration is achieved by vacuum distillation at a temperature of 40-60 °C, preferably 50 °C, for a duration of 60-300 min. The inventors discovered during experiments that without the addition of graphene quantum dot dispersion, films with high transmittance could be successfully prepared using the same UV curing agent and curing parameters. However, after adding the graphene quantum dot dispersion, the film was white. Analysis revealed that this was because DCPDA, after curing, is insoluble in ethanol and precipitates as fine particles, gradually forming a porous, sponge-like structure. This increases visible light scattering, negatively impacting optical transparency. The inventors further refined the vacuum distillation process by strictly controlling the distillation time to minimize the solvent's influence on visible light transmittance. If the vacuum distillation time was too short, the visible light transmittance was extremely poor; if the distillation time was too long, the effect on transmittance no longer improved.

[0026] This invention does not limit the coating method, and those skilled in the art can choose according to the actual situation. For example, spraying, scraping, dipping, spin coating, etc. can be used.

[0027] In this embodiment, the substrate is glass.

[0028] In this embodiment, the thickness of the wet film is 200~800 μm.

[0029] In this embodiment, ultraviolet curing is used during the curing process. The ultraviolet light wavelength is 365~405nm, the curing distance (i.e., the distance between the curing lamp and the wet film surface) is 6~18cm, preferably 12cm, and a two-stage curing process is employed. The first stage curing time is 1~3s, preferably 2s, and the first stage curing power is 10%~40% of the maximum power, preferably 25%. The second stage curing time is 7~9s, preferably 7s, and the second stage curing power is 70%~100% of the maximum power, preferably 80%. The maximum power is 1500mW / cm². 2 During the experiment, the inventors discovered that when using single-pass curing, if the power is too low, the film will not be able to cure completely; if the power is too high, the polymerization rate will be too fast, and the polymer will crack after curing. Therefore, a two-pass curing method was adopted, and the curing time and power of the first pass were controlled to be lower than the curing time and power of the second pass, respectively, to prevent direct curing and incomplete curing.

[0030] In a second aspect, the present invention provides a fluorescent particle-induced supertransmittance radiation-cooling film, which is obtained by the preparation method of the fluorescent particle-induced supertransmittance radiation-cooling film provided in the first aspect of the present invention.

[0031] In some preferred embodiments of the present invention, by controlling the mass ratio of DCPDA monomer to graphene quantum dot dispersion (1:(0.5~5)), the mass ratio of DCPDA monomer to UV curing agent (1:(0.02~0.045)), the temperature of vacuum distillation (40~60 ℃), the time of vacuum distillation (60~300 min), the thickness of wet film (200~800 μm), the curing distance (6~18 cm), the first curing time (1~3 s), the first curing power (10%~40% of the maximum power), the second curing time (7~9 s), and the second curing power (70%~100% of the maximum power), the transmittance of the fluorescent particle-induced supertransmittance radiation cooling film can be controlled to be above 80%.

[0032] Thirdly, the present invention provides an application of a fluorescent particle-induced supertransmittance radiation cooling film, which is used in fields such as building energy conservation, photovoltaic cell cooling, and cold chain transportation.

[0033] In some specific embodiments of the present invention, the fluorescent particle-induced supertransmittance radiation cooling film is used as an encapsulation material for solar cells.

[0034] When the fluorescent particle-induced supertransmittance radiation cooling film of the present invention is used as an encapsulation material for solar cells, it can achieve a combined improvement in cooling effect and battery performance (e.g., PCE) compared to commercial glass as an encapsulation material.

[0035] This invention does not limit the type of solar cell, and those skilled in the art can choose according to the actual situation. In some specific embodiments of this invention, the solar cell is an mc-Si solar cell.

[0036] To avoid redundancy, the preparation methods of graphene quantum dot dispersions in the following embodiments and comparative examples of this invention are as follows: 5 mg of OPD and 5 mg of oxalic acid were dissolved in 25 mL of ethanol. The resulting mixture was transferred to a polytetrafluoroethylene (PTFE)-lined high-pressure reactor and sonicated for 5 min. The reactor was then placed in an oven and heated at a rate of 8 °C / min until it reached 160 °C. The reaction time was 24 h. After the reaction was completed, the reactor was cooled to room temperature and removed to obtain a graphene quantum dot dispersion (approximately 0.001% by mass).

[0037] Example 1 (1) Add 10 g of DCPDA monomer and 0~50 g of graphene quantum dot dispersion to a weighing bottle, then add 0.2~0.45 g of UV curing agent (TPO-L), and then stir and sonicate in the dark in sequence to make the system disperse evenly and obtain a mixture; wherein, the temperature of stirring and sonication is 50 ℃ and the time of stirring and sonication is 2 h; (2) Transfer the mixture to a single-necked flask and distill under reduced pressure at 50 °C for 0-300 min to remove excess solvent and obtain casting solution; (3) The casting liquid is applied to the glass surface by scraping, and the wet film thickness is controlled to be 200~800 μm by adjusting the scraper scale; (4) Transfer the wet film to a UV curing chamber (Shanghai Runduo, model: UVK80), set the curing distance to 6~18 cm, and perform double curing. The first curing time is 1~3 s and the first curing power is 10%~50% of the maximum power; the second curing time is 7~9 s and the second curing power is 60%~100% of the maximum power. Perform UV curing to obtain a fluorescent particle-induced supertransmittance radiation cooling film (TTEG).

[0038] The relevant preparation parameters and visible light transmittance test results of different samples in Example 1 are shown in Table 1.

[0039] Table 1. Relevant preparation parameters and visible light transmittance test results for different samples in Example 1.

[0040] Note: The visible light transmittance in Table 1 refers to the average transmittance of visible light in the 400-800 nm wavelength range; the average transmittance mentioned in this patent refers to the weighted average transmittance with the solar spectrum AM1.5 as the weight.

[0041] Example 2 Fabrication of a 5 cm × 5 cm mc-Si solar cell: Please refer to [link / reference]. Figure 8 First, commercial EVA hot melt adhesive (A02, Tongda) is coated on the surface of commercial TPT backsheet film (MSL-300, ALLMEJORES). Then, a polycrystalline silicon wafer is quickly placed on it. After the hot melt adhesive cools and fixes the polycrystalline silicon wafer, commercial EVA hot melt adhesive (A02, Tongda) is applied again. The prepared TTEG film (E-8) is then quickly placed on it. After curing, the encapsulated solar cell is obtained.

[0042] Comparative Example 1 Compared to Example 2, the only difference is that the encapsulation material is replaced with commercial glass (Luoyang Guluo Glass Co., Ltd., 5). 5cm).

[0043] Performance testing (1) Visible light transmittance: The UV-Vis-NIR transmittance (0.3~0.9μm) was measured using a spectrophotometer (UV-2550, Japan). The test results are shown in Table 1 and Figure 3 .

[0044] (2) Film formation effect: The film formation effect of the film was observed by optical photography. The test results are shown in […]. Figure 1 .

[0045] (3) Microstructure of the thin film: The microstructure of the thin film was observed using a field emission scanning electron microscope (FESEM, JSM-7500F). The test results are shown in the figure. Figure 2 and 7 .

[0046] (4) Fluorescence effect: The sample was irradiated with 365nm ultraviolet light in a dark environment. The test results are shown in [the table below]. Figure 4 .

[0047] (5) Simulation verification: A three-dimensional simulation model and region were established using FDTD software. The light source was set as a plane wave incident perpendicularly along the normal direction (in the z-direction of the model). Periodic boundary conditions were set on both sides to reduce computation time. At the same time, perfectly matched layers were applied at the top and bottom along the z-direction. The simulation results are shown in […]. Figure 5 .

[0048] (6) UV-Vis-NIR transmittance: Measured using a UV-Vis-NIR spectrophotometer (PE, USA) (0.3~2.5μm). The test results are shown in […]. Figure 6.

[0049] (7) Mid-infrared emissivity: The infrared spectral emissivity (4~25μm) was measured using a Fourier transform near-infrared spectrometer (PE, USA). The test results are shown in […]. Figure 6 .

[0050] (8) Fluorescent particle-induced visible light transmittance: Under a solar simulator (AM 1.5G), the light flux of commercial glass and TTEG was tested using a handheld radiometer. The data measured by the handheld radiometer were recorded and their arithmetic mean was calculated. By comparing the difference between the arithmetic mean, the fluorescence-induced visible light transmittance of the tested sample was semi-quantitatively evaluated.

[0051] (9) Efficiency of a 5 cm × 5 cm mc-Si solar cell: in a solar simulator (AM1.5, 100 mW·cm) -2 The JV curves of the glass- and TTEG-encapsulated batteries were measured using a digital source meter (KEITHLEY 2400). The test results are shown below. Figure 9 and 11 .

[0052] (10) Outdoor temperature performance test of 5 cm × 5 cm mc-Si solar cells: Temperature measuring wires were directly attached to the outer surface of the backsheet of the solar panel to test the back temperature of the glass and TTEG-encapsulated cells. A weather station was set up near the experimental setup to monitor wind speed, humidity, irradiance, and ambient temperature throughout the test. The test scheme strictly replicated real-world conditions without introducing artificial convection barriers such as polyethylene film, thus ensuring that the experimental results accurately reflected the thermoelectric coupling behavior of the equipment under actual operating conditions. The test results are shown in […]. Figure 10 .

[0053] Please refer to Table 1 and Figure 1 Through Table 1 and Figure 1 It can be seen that samples E-1 to E-8 in Example 1 of this invention all have high visible light transmittance (≥80%), and the visible light transmittance of sample E-8 is >90%, indicating that within a certain range of preparation parameters, fluorescent particle-induced supertransmittance radiation-cooled films with high visible light transmittance can be obtained. Compared with experimental groups E-1 to E-8, in experimental groups F-1 and F-2, the excessively low vacuum distillation time resulted in extremely low visible light transmittance even after film formation; in experimental group F-3, the first-stage UV curing power was too high and the second-stage UV curing power was too low, causing the film to crack. This indicates that the vacuum distillation time and curing conditions (first-stage UV curing power and second-stage UV curing power) are key factors for the successful preparation of the film.

[0054] Please see Figure 2 ,pass Figure 2It can be seen that when the vacuum distillation time is too low, the DCPDA becomes insoluble in ethanol after curing and precipitates as fine particles, gradually forming a porous sponge-like structure, which increases visible light scattering and thus adversely affects optical transparency. In addition, combined with other results, it can be seen that when the first stage power is too high, the violent polymerization reaction and the difference in properties between DCPDA and the substrate material lead to film breakage. This further verifies that the vacuum distillation time and curing conditions (first stage UV curing power and second stage UV curing power) are key factors for the successful preparation of films with high visible light transmittance.

[0055] Please refer to Table 1 and Figure 3 Through Table 1 and Figure 3 It can be seen that without the addition of graphene quantum dots, DCPDA still has a high transmittance in the 300~400nm range. However, this part of the light is not beneficial to the solar cell and will instead generate additional heat, causing the temperature of the solar panel to rise. By controlling the process parameters, the visible light transmittance is highest when an appropriate amount (10g) of graphene quantum dot film is added.

[0056] Please see Figure 4 ,pass Figure 4 It can be seen that under ultraviolet light irradiation, the film without graphene quantum dots appears black due to the absorption of ultraviolet light by the DCPDA. When a small amount of graphene quantum dots is added, the overall refractive index of the system decreases slightly due to their low refractive index, resulting in better refractive index matching at the air / polymer interface, thereby reducing interface reflection and showing an increase in transmittance. When too much graphene quantum dots are added, they tend to agglomerate, causing many white bright spots to appear inside the film. Due to agglomeration and density differences, local refractive index fluctuations occur, further enhancing scattering and leading to a decrease in transmittance.

[0057] Please see Figure 5 ,pass Figure 5 It can be seen that introducing randomly distributed graphene quantum dots (GQDs) into a DCPDA can locally enhance the electric field and improve vertical transmission. The GQDs form a nanoscale resonant structure, enhancing incident coupling and energy redistribution, thereby improving the propagation efficiency of light in non-absorption paths and increasing transmittance. Conversely, in a pure DCPDA, light is mainly confined to the upper region, and the electric field energy observed at the bottom is negligible. These results indicate that the introduction of graphene quantum dots enhances the interaction efficiency between the particles and the structure, thereby increasing the transmitted light intensity and improving the overall transmittance of the system.

[0058] Please see Figure 6 ,pass Figure 6It can be seen that the average transmittance of TTEG(E-8) prepared in Example 1 of this invention is 89.2% in the visible light band of 400~800nm, while the average transmittance of glass in the same band is 89.0%. The average mid-infrared emissivity of TTEG(E-8) prepared in Example 1 of this invention in the 8~13μm atmospheric window is approximately 0.95, indicating that the fluorescent particle-induced supertransmittance radiation-cooled film of this invention possesses both high visible light transmittance and high emissivity. Furthermore, the arithmetic mean of the data measured by a handheld radiometer shows that the fluorescent particle-induced visible light transmittance of the radiation-cooled film (95.6%) is 4.8% higher than that of glass (90.8%).

[0059] Please see Figure 7 ,pass Figure 7 It can be seen that the thickness of the E-8 sample in Example 1 of this invention is approximately 480 μm.

[0060] Please see Figure 9 ,pass Figure 9 It can be seen that in indoor tests, the PCE of commercial glass-encapsulated mc-Si solar cells is 12.46% (V). oc =2.45 V, J sc =7.18 mA·cm -2 FF=70.7%); in comparison, the PCE of TTEG-encapsulated mc-Si solar cells is 12.85% (V). oc =2.46 V, J sc =7.43 mA·cm -2 (FF=70.5%). The results above show that the increase in PCE is mainly due to the increase in Jsc, which is directly affected by visible light transmittance. This indicates that enhanced photothermal management helps to effectively promote the synergistic improvement of the electrical performance of mc-Si solar cells.

[0061] Please see Figure 10 ,pass Figure 10 It can be seen that the average solar irradiance from 11:00 AM to 3:00 PM is 474.2 W·m. -2 The outdoor radiative cooling performance was verified. Compared with commercial glass, TTEG encapsulation reduced the surface temperature by an average of 5.6°C (with a maximum reduction of 9°C).

[0062] Please see Figure 11 ,pass Figure 11 It can be seen that in indoor tests, the TTEG-packaged battery exhibits superior electrical performance when its temperature is 9°C lower than that of the commercial glass-packaged battery (TTEG: 35°C, Glass: 44°C). The PCE of the commercial glass-packaged battery is 10.57% (V).oc =2.28 V, J sc =7.34 mA·cm -2 (FF=63.1%). In comparison, the PCE of TTEG encapsulation is 12.43% (V). oc =2.37 V, J sc =7.6 mA·cm -2 (FF=69.1%). The results show that PCE increased by 17.6%, and the improvement in PCE was mainly due to V. oc J sc Simultaneous improvement with FF. Among them, J... sc The improvement is due to the increase in transmittance, while V oc The improvement in FF is due to the enhanced radiative cooling performance. It is evident that TTEG effectively mitigates the efficiency losses of traditional packaging materials.

[0063] Compared with the prior art, the beneficial effects of the present invention include: (1) High light transmittance and high emissivity: On the one hand, randomly embedded graphene quantum dots can enhance the local electric field and improve the vertical transmission of light; on the other hand, graphene quantum dots convert short-wavelength light into visible light, further improving the visible light transmittance; at the same time, DCPDA has high emissivity in the 8~13μm band, which allows the film to transmit light during the day and radiate strongly in the atmospheric window band, thereby achieving efficient cooling.

[0064] (2) Simple preparation: It is prepared by solution method, and the process is similar to the preparation process of existing radiation cooling film and fluorescent long afterglow film. It does not require complex micro-nano etching or vacuum deposition equipment and is suitable for mass production.

[0065] (3) Wide range of applications: The film has good flexibility and can be made into a thickness of 200~800μm. It is suitable for surfaces such as glass windows, car roofs, and photovoltaic modules, and has energy-saving and environmental benefits.

[0066] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a fluorescent particle-induced supertransmittance radiation-cooled thin film, characterized in that, Includes the following steps: The DCPDA monomer, graphene quantum dot dispersion, and UV curing agent are mixed evenly to obtain a mixture. After concentration, the mixture is used to obtain a casting solution; The casting solution is applied to the substrate surface to obtain a wet film; The wet film is cured to obtain a fluorescent particle-induced supertransmittance radiation-cooled film.

2. The method for preparing a fluorescent particle-induced supertransmittance radiation-cooled thin film according to claim 1, characterized in that, The graphene quantum dot dispersion has a mass fraction of 0.0005%~0.002%, and the solvent is an alcohol solvent; and / or, The mass ratio of the DCPDA monomer to the graphene quantum dot dispersion is 1:(0.5~5); or, The mass ratio of the DCPDA monomer to the graphene quantum dot dispersion is 1:(1~2).

3. The method for preparing a fluorescent particle-induced supertransmittance radiation-cooled thin film according to claim 1, characterized in that, The preparation method of the graphene quantum dot dispersion includes: o-Phenylenediamine and a catalyst were dispersed in an alcohol solvent, followed by a solvothermal reaction to obtain a graphene quantum dot dispersion; wherein, The catalyst is at least one of oxalic acid and acetic acid; and / or, The mass ratio of o-phenylenediamine to catalyst is 1:(0.3~3); and / or, The alcohol solvent is at least one selected from methanol, ethanol, and ethylene glycol; and / or, The ratio of o-phenylenediamine to alcohol solvent is 0.1~0.3 mg:1 mL; and / or, The temperature of the solvothermal reaction is 80~200℃, the time of the solvothermal reaction is 4~36h, and the heating rate is 5~10℃ / min.

4. The method for preparing a fluorescent particle-induced supertransmittance radiation-cooled thin film according to claim 1, characterized in that, The UV curing agent is ethyl 2,4,6-trimethylbenzoylphenylphosphonate; and / or... The mass ratio of the DCPDA monomer to the UV curing agent is 1:(0.02~0.045).

5. The method for preparing a fluorescent particle-induced supertransmittance radiation-cooled thin film according to claim 1, characterized in that, The process of uniformly mixing the DCPDA monomer, graphene quantum dot dispersion, and UV curing agent includes: first stirring at 40-60°C in the dark for 1-3 hours, then sonicating at 40-60°C in the dark for 1-3 hours; and / or, The concentration is achieved by vacuum distillation, with the temperature of vacuum distillation being 40~60 ℃ and the time being 60~300 min.

6. The method for preparing a fluorescent particle-induced supertransmittance radiation-cooled thin film according to claim 1, characterized in that, The substrate is glass; and / or, The thickness of the wet film is 200~800 μm.

7. The method for preparing a fluorescent particle-induced supertransmittance radiation-cooled thin film according to claim 1, characterized in that, The curing process employs ultraviolet (UV) curing with a wavelength of 365–405 nm and a curing distance of 6–18 cm. It is a two-stage curing process: the first stage lasts 1–3 seconds with a curing power of 10%–40% of the maximum power; the second stage lasts 7–9 seconds with a curing power of 70%–100% of the maximum power; the maximum power is 1500 mW / cm². 2 .

8. A fluorescent particle-induced supertransmittance radiation-cooled thin film, characterized in that, The fluorescent particle-induced supertransmittance radiation-cooling film is obtained by the preparation method of the fluorescent particle-induced supertransmittance radiation-cooling film according to any one of claims 1 to 7.

9. An application of the fluorescent particle-induced supertransmittance radiation-cooling thin film as described in claim 8, characterized in that, The fluorescent particle-induced supertransmittance radiation cooling film is applied in building energy conservation, photovoltaic cell cooling, and cold chain transportation.

10. The application of the fluorescent particle-induced supertransmittance radiation-cooling thin film according to claim 9, characterized in that, The fluorescent particle-induced supertransmittance radiation-cooling film is used as an encapsulation material for solar cells.

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