Composite film material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of solar energy utilization, in particular to a composite film material and a preparation method and application thereof. The composite film material comprises the following preparation raw materials in parts by mass: 5-20 parts of an inorganic semiconductor nanomaterial, 75-90 parts of an organic conjugated polymer and 1-5 parts of a surface modifier, the inorganic semiconductor nanomaterial is selected from tungsten disulfide or molybdenum disulfide nanosheets; the organic conjugated polymer is selected from poly (3-hexylthiophene-2, 5-diyl) or poly [bis (4-phenyl) (2, 4, 6-trimethylphenyl) amine]; and the surface modifying agent is 3-amino propyl triethoxy silane. An inorganic semiconductor nanomaterial and an organic conjugated polymer are accurately selected to construct a light absorption system covering ultraviolet-visible-near infrared full wave bands; 3-aminopropyltriethoxysilane is introduced, so that the problems that an inorganic phase is easy to agglomerate and has many interface defects are effectively solved, and a structural guarantee is provided for stable exertion of the light absorption performance and the photothermal conversion performance of the material.

Description

Technical Field

[0001] This invention relates to the field of solar energy utilization technology, and in particular to a composite thin film material, its preparation method, and its application. Background Technology

[0002] Solar energy, as a clean and renewable energy source, is crucial for achieving the "dual carbon" goal. Solar absorbing materials, as core components of technologies such as photothermal conversion and photovoltaic power generation, directly affect the overall efficiency of solar energy utilization. Currently, common absorbing materials mainly include inorganic thin films, organic thin films, and metal-ceramic composite coatings.

[0003] However, existing materials all have certain limitations: inorganic thin films (such as perovskites), while possessing high absorption coefficients, suffer from poor stability and susceptibility to degradation by water, oxygen, and light, and some preparation processes are complex (e.g., magnetron sputtering relies on a high vacuum environment); organic thin films are flexible and have simple processes, but suffer from low absorption coefficients and limited photothermal conversion efficiency; metal-ceramic composite coatings exhibit excellent stability, but suffer from narrow absorption bands and high preparation costs. Furthermore, in most composite thin film materials, the inorganic and organic phases have poor compatibility and numerous interface defects, exacerbating carrier recombination and thus affecting absorption efficiency and long-term stability.

[0004] Therefore, developing a composite thin film material that combines the advantages of high light absorption coefficient, good stability, simple preparation process and low cost is of great significance. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the prior art by providing a composite thin film material, its preparation method, and its application. By precisely selecting inorganic semiconductor nanomaterials and organic conjugated polymers, a light absorption system covering the entire ultraviolet-visible-near-infrared wavelength range is constructed. At the same time, by innovatively introducing 3-aminopropyltriethoxysilane as a surface modifier, the key problems of easy aggregation of inorganic phases and numerous interface defects in traditional organic-inorganic composite thin films are effectively solved, providing structural assurance for the stable performance of the material's light absorption and photothermal conversion properties.

[0006] To achieve the above objectives, the present invention provides a composite thin film material comprising the following raw materials in parts by weight: 5-20 parts of inorganic semiconductor nanomaterials, 75-90 parts of organic conjugated polymers, and 1-5 parts of surface modifiers; Among them, the inorganic semiconductor nanomaterial is selected from tungsten disulfide nanosheets or molybdenum disulfide nanosheets; the organic conjugated polymer is selected from poly(3-hexylthiophene-2,5-diyl) or poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]; and the surface modifier is 3-aminopropyltriethoxysilane.

[0007] Preferably, the inorganic semiconductor nanomaterial has a sheet diameter of 50-200 nm and a thickness of 1-5 nm.

[0008] The present invention also provides a method for preparing the aforementioned composite thin film material, comprising the following steps: (1) Inorganic semiconductor nanomaterials, surface modifiers and solvents are mixed and reacted to obtain a dispersion; (2) Mix the dispersion and the organic conjugated polymer solution to obtain the precursor solution; (3) The precursor solution is applied to the substrate surface and annealed to obtain the composite film material.

[0009] Preferably, in step (1), the solvent is ethanol, and the ratio of the mass of the inorganic semiconductor nanomaterial to the volume of the solvent is 1 mg: 1-2 mL.

[0010] Preferably, in step (1), the reaction temperature is 60-80℃ and the time is 2-4h.

[0011] Preferably, in step (1), after the reaction is completed, the modified inorganic nanomaterial is obtained and dispersed in chlorobenzene to obtain a dispersion; the concentration of the modified inorganic nanomaterial in the dispersion is 5-10 mg / mL.

[0012] Preferably, in step (2), the solvent of the organic conjugated polymer solution is chlorobenzene, and the concentration of the organic conjugated polymer in the organic conjugated polymer solution is 10-20 mg / mL.

[0013] Preferably, in step (3), the coating method is spin coating, the spin coating speed is 3000-5000 rpm, and the time is 30-45 s.

[0014] Preferably, in step (3), the annealing temperature is 80-120℃ and the time is 10-30min.

[0015] The present invention also provides the application of the composite thin film material described above, or the composite thin film material prepared according to the preparation method of the composite thin film material described above, in solar light absorption.

[0016] The beneficial effects of this invention are as follows: 1. This invention provides a composite thin film material comprising the following raw materials in parts by weight: 5-20 parts of inorganic semiconductor nanomaterials, 75-90 parts of organic conjugated polymers, and 1-5 parts of surface modifiers; wherein the inorganic semiconductor nanomaterials are selected from tungsten disulfide nanosheets or molybdenum disulfide nanosheets; the organic conjugated polymers are selected from poly(3-hexylthiophene-2,5-diyl) or poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]; and the surface modifier is 3-aminopropyltriethoxysilane.

[0017] This invention constructs a light-absorbing system covering the entire ultraviolet-visible-near-infrared wavelength range by precisely selecting inorganic semiconductor nanomaterials and organic conjugated polymers. The selected tungsten disulfide or molybdenum disulfide nanosheets possess excellent broadband light absorption capabilities, effectively capturing light energy from the visible to near-infrared region of the solar spectrum. Combined with the conjugated organic conjugated polymer, the synergistic effect of full-band light absorption is further enhanced. Furthermore, this invention innovatively introduces 3-aminopropyltriethoxysilane as a surface modifier. The amino groups in its molecule can undergo condensation reactions with the hydroxyl groups on the surface of the inorganic semiconductor nanomaterials to form stable chemical bonds, while the alkoxy groups can form a well-compatible interface with the conjugated structure of the organic conjugated polymer, thus constructing a tightly integrated composite system of "inorganic nanosheets-surface modifier-organic polymer". This structure effectively solves the key problems of easy aggregation of the inorganic phase and numerous interface defects in traditional organic-inorganic composite films. It not only helps maintain the light-absorbing area but also significantly reduces the carrier recombination probability, providing structural assurance for the stable performance of the material's light absorption and photothermal conversion properties.

[0018] This invention achieves long-term stability of the composite film through the synergistic effect of organic conjugated polymers and surface modifiers. The organic conjugated polymer forms a continuous matrix phase, which can block water and oxygen from direct contact with inorganic semiconductor nanomaterials, preventing oxidative degradation of the nanosheets. The residual amino groups after modification with 3-aminopropyltriethoxysilane can also adsorb trace amounts of water and oxygen, further enhancing the barrier effect. Therefore, the composite film of this invention can effectively resist structural degradation under long-term light exposure, and its service life is significantly better than that of existing similar materials, meeting the needs of long-term exposed applications such as solar water heaters and outdoor collectors.

[0019] Based on its wide-band high light absorption performance and excellent interface structure, the composite thin film of this invention exhibits highly efficient photothermal conversion capabilities. Wide-band light absorption ensures sufficient light energy capture, the flat and dense interface structure reduces energy loss caused by carrier recombination, and the good bonding between the organic polymer and inorganic nanosheets promotes heat conduction. Thus, the thin film can efficiently convert absorbed sunlight into heat energy, resulting in significant energy conversion benefits and providing high-performance material support for solar thermal utilization technology.

[0020] 2. This invention employs a preparation route of "solution mixing-spin-coating-annealing," eliminating the need for high-vacuum equipment, anhydrous and oxygen-free glove boxes, or high-temperature and high-pressure reaction conditions. Preparation can be completed using only conventional laboratory instruments, resulting in a simple and highly controllable process. Raw material costs are low, and the preparation process does not involve complex chemical reactions or expensive reagent consumption. Furthermore, this process is compatible with roll-to-roll production, facilitating large-area, high-efficiency preparation.

[0021] The preparation method of this invention has no strict requirements on the substrate type and can be applied to rigid substrates (such as ITO conductive glass and quartz glass) and flexible substrates (such as PET). The film thickness can be flexibly adjusted within the range of 50-200 nm to meet different application needs. In addition, this material can be used directly as a photothermal conversion layer in photothermal devices, or as an auxiliary light-absorbing layer in perovskite / silicon-based solar cells, broadening the light absorption band of the cell and realizing multi-scenario adaptation of "photothermal-photovoltaic". Detailed Implementation

[0022] This invention provides a composite thin film material comprising the following raw materials in parts by weight: 5-20 parts of inorganic semiconductor nanomaterials, 75-90 parts of organic conjugated polymers, and 1-5 parts of surface modifiers; Among them, the inorganic semiconductor nanomaterial is selected from tungsten disulfide nanosheets or molybdenum disulfide nanosheets; the organic conjugated polymer is selected from poly(3-hexylthiophene-2,5-diyl) or poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]; and the surface modifier is 3-aminopropyltriethoxysilane.

[0023] In this invention, the inorganic semiconductor nanomaterial has a sheet diameter of 50-200 nm and a thickness of 1-5 nm.

[0024] The present invention also provides a method for preparing the aforementioned composite thin film material, comprising the following steps: (1) Inorganic semiconductor nanomaterials, surface modifiers and solvents are mixed and reacted to obtain a dispersion; (2) Mix the dispersion and the organic conjugated polymer solution to obtain the precursor solution; (3) The precursor solution is applied to the substrate surface and annealed to obtain the composite film material.

[0025] In this invention, in step (1), the solvent is ethanol, and the ratio of the mass of the inorganic semiconductor nanomaterial to the volume of the solvent is 1 mg: 1-2 mL.

[0026] In this invention, step (1) includes: dispersing inorganic semiconductor nanomaterials in a solvent and adding a surface modifier.

[0027] In this invention, in step (1), the reaction temperature is 60-80℃, the stirring speed is 500-800rpm, and the time is 2-4h.

[0028] In this invention, in step (1), after the reaction is completed, centrifugation and washing are performed sequentially to obtain modified inorganic nanomaterials, which are then dispersed in chlorobenzene to obtain a dispersion; the concentration of the modified inorganic nanomaterials in the dispersion is 5-10 mg / mL.

[0029] In this invention, the centrifugation speed is 8000-10000 rpm and the time is 10-15 min; the washing reagent is ethanol, and the washing is performed 2-3 times.

[0030] In this invention, in step (2), the solvent of the organic conjugated polymer solution is chlorobenzene, and the concentration of the organic conjugated polymer in the organic conjugated polymer solution is 10-20 mg / mL.

[0031] In this invention, step (2) involves preparing the organic conjugated polymer solution by dissolving the organic conjugated polymer in a solvent and stirring for 1-2 hours at a temperature of 40-60°C and a rotation speed of 300-500 rpm to obtain the organic conjugated polymer solution.

[0032] In this invention, in step (2), the mixing is carried out by stirring at room temperature for 30-60 minutes; after the mixing is completed, the mixture is filtered through a 0.20-0.24 micrometer filter membrane to obtain the precursor solution.

[0033] In this invention, in step (3), the coating method is spin coating, the spin coating speed is 3000-5000 rpm, and the time is 30-45s.

[0034] In this invention, in step (3), the substrate includes ITO conductive glass, quartz glass or polyethylene terephthalate (PET) flexible substrate.

[0035] In this invention, in step (3), the annealing temperature is 80-120℃ and the time is 10-30min.

[0036] In this invention, in step (3), after the annealing process is completed, the material is naturally cooled to room temperature to obtain a composite film material.

[0037] In this invention, the thickness of the composite thin film material is 50-200 nm.

[0038] The present invention also provides the application of the composite thin film material described above, or the composite thin film material prepared according to the preparation method of the composite thin film material described above, in solar light absorption.

[0039] The present invention will be further described below with reference to embodiments. Unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art. The features mentioned above or in the specific examples mentioned in this invention can be combined arbitrarily, and these specific embodiments are only used to illustrate the invention and are not intended to limit the scope of the invention.

[0040] In the following examples and comparative examples of the present invention, tungsten disulfide nanosheets and molybdenum disulfide nanosheets were purchased from Aladdin, poly(3-hexylthiophene-2,5-diyl) and poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] were purchased from Sigma, and 3-aminopropyltriethoxysilane was purchased from Sinopharm Group.

[0041] Example 1 This embodiment provides a composite thin film material comprising the following raw materials in parts by weight: 10 parts of molybdenum disulfide nanosheets (100 nm in diameter and 2 nm in thickness), 87 parts of poly(3-hexylthiophene-2,5-diyl), and 3 parts of 3-aminopropyltriethoxysilane.

[0042] This embodiment also provides a method for preparing the above-mentioned composite thin film material, including the following steps: Molybdenum disulfide nanosheets were dispersed in ethanol (volume ratio of molybdenum disulfide nanosheets to ethanol was 1 mg: 1 mL), and 3-aminopropyltriethoxysilane was added. The mixture was reacted at 70 °C and 600 rpm for 3 h. After the reaction was completed, the mixture was centrifuged at 9000 rpm for 12 min and then washed twice with ethanol to obtain the modified inorganic nanomaterial. The modified inorganic nanomaterial was then dispersed in chlorobenzene to obtain a dispersion with a concentration of 10 mg / mL.

[0043] Poly(3-hexylthiophene-2,5-diyl) was dissolved in chlorobenzene and stirred for 1.5 h at 50 °C and 400 rpm to obtain an organic conjugated polymer solution with a concentration of 20 mg / mL. The dispersion and the organic conjugated polymer solution were mixed and stirred at room temperature for 45 min. The mixture was then filtered through a 0.22 μm filter membrane to obtain the precursor solution.

[0044] The precursor solution was spin-coated onto ITO conductive glass (2 cm long and 2 cm wide) at a spin speed of 4000 rpm for 40 s. After spin-coating, the glass was annealed at 100 °C for 20 min and then naturally cooled to room temperature to obtain a composite thin film material with a thickness of 120 nm.

[0045] Example 2 This embodiment provides a composite thin film material comprising the following raw materials in parts by weight: 15 parts of tungsten disulfide nanosheets (120 nm in diameter and 3 nm in thickness), 83 parts of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], and 2 parts of 3-aminopropyltriethoxysilane.

[0046] This embodiment also provides a method for preparing the above-mentioned composite thin film material, including the following steps: Tungsten disulfide nanosheets were dispersed in ethanol (volume ratio of tungsten disulfide nanosheets to ethanol was 3 mg: 4 mL), and 3-aminopropyltriethoxysilane was added. The mixture was reacted at 65 °C and 500 rpm for 2.5 h. After the reaction was completed, the mixture was centrifuged at 8500 rpm for 10 min and then washed three times with ethanol to obtain the modified inorganic nanomaterial. The modified inorganic nanomaterial was then dispersed in chlorobenzene to obtain a dispersion with a concentration of 10 mg / mL.

[0047] Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] was dissolved in chlorobenzene and stirred at 45°C and 300 rpm for 2 hours to obtain an organic conjugated polymer solution with a concentration of 10 mg / mL. The dispersion and the organic conjugated polymer solution were mixed and stirred at room temperature for 60 minutes. The mixture was then filtered through a 0.22-micron filter membrane to obtain the precursor solution.

[0048] The precursor solution was spin-coated onto a flexible PET substrate (2 cm long and 2 cm wide) at a spin speed of 3500 rpm for 35 s. After spin-coating, the substrate was annealed at 95 °C for 25 min and then allowed to cool naturally to room temperature to obtain a composite film material with a thickness of 100 nm.

[0049] Example 3 This embodiment provides a composite thin film material comprising the following raw materials in parts by weight: 8 parts of molybdenum disulfide nanosheets (80 nm in diameter and 2 nm in thickness), 90 parts of poly(3-hexylthiophene-2,5-diyl), and 2 parts of 3-aminopropyltriethoxysilane.

[0050] This embodiment also provides a method for preparing the above-mentioned composite thin film material, including the following steps: Molybdenum disulfide nanosheets were dispersed in ethanol (volume ratio of molybdenum disulfide nanosheets to ethanol was 1 mg: 1 mL), and 3-aminopropyltriethoxysilane was added. The mixture was reacted at 70 °C and 600 rpm for 3 h. After the reaction was completed, the mixture was centrifuged at 9000 rpm for 12 min and then washed twice with ethanol to obtain the modified inorganic nanomaterial. The modified inorganic nanomaterial was then dispersed in chlorobenzene to obtain a dispersion with a concentration of 10 mg / mL.

[0051] Poly(3-hexylthiophene-2,5-diyl) was dissolved in chlorobenzene and stirred for 1.5 h at 50 °C and 400 rpm to obtain an organic conjugated polymer solution with a concentration of 20 mg / mL. The dispersion and the organic conjugated polymer solution were mixed and stirred at room temperature for 45 min. The mixture was then filtered through a 0.22 μm filter membrane to obtain the precursor solution.

[0052] The precursor solution was spin-coated onto quartz glass (2 cm long and 2 cm wide) at a spin speed of 4500 rpm for 40 s. After spin-coating, the glass was annealed at 110 °C for 20 min and then allowed to cool naturally to room temperature to obtain a composite thin film material with a thickness of 100 nm.

[0053] Comparative Example 1 This comparative example provides a thin film material comprising the following raw materials in parts by mass: 10 parts of molybdenum disulfide nanosheets (100 nm in diameter and 2 nm in thickness) and 90 parts of poly(3-hexylthiophene-2,5-diyl).

[0054] This comparative example also provides a method for preparing the above-mentioned thin film material, including the following steps: Molybdenum disulfide nanosheets were dispersed in chlorobenzene to obtain a dispersion with a concentration of 10 mg / mL. Poly(3-hexylthiophene-2,5-diyl) was dissolved in chlorobenzene and stirred for 1.5 h at 50 °C and 400 rpm to obtain an organic conjugated polymer solution with a concentration of 20 mg / mL. The dispersion and the organic conjugated polymer solution were mixed and stirred at room temperature for 45 min. The mixture was then filtered through a 0.22 μm filter membrane to obtain the precursor solution.

[0055] The precursor solution was spin-coated onto ITO conductive glass (2 cm long and 2 cm wide) at a spin speed of 4000 rpm for 40 s. After spin-coating, the glass was annealed at 100 °C for 20 min and then naturally cooled to room temperature to obtain a thin film material with a thickness of 120 nm.

[0056] Comparative Example 2 This comparative example provides a thin film material comprising the following raw materials in parts by mass: 100 parts of molybdenum disulfide nanosheets (100 nm in diameter and 2 nm in thickness).

[0057] This comparative example also provides a method for preparing the above-mentioned thin film material, including the following steps: Molybdenum disulfide nanosheets were dispersed in chlorobenzene to obtain a dispersion with a concentration of 10 mg / mL. The dispersion was spin-coated onto ITO conductive glass (2 cm long and 2 cm wide) at a speed of 4000 rpm for 40 s. After spin-coating, the glass was annealed at 100 °C for 20 min and then naturally cooled to room temperature to obtain a thin film material with a thickness of 120 nm.

[0058] Comparative Example 3 This comparative example provides a thin film material comprising the following raw materials in parts by mass: 30 parts of molybdenum disulfide nanosheets (100 nm in diameter and 2 nm in thickness), 67 parts of poly(3-hexylthiophene-2,5-diyl), and 3 parts of 3-aminopropyltriethoxysilane.

[0059] This comparative example also provides a method for preparing the above-mentioned thin film material, which is the same as in Example 1.

[0060] Experimental Example 1 The light absorption capacity of the composite film materials in Examples 1-3 and the film materials in Comparative Examples 1-3 was tested, and the test results are recorded in Table 1. The tests were conducted using a PerkinElmer Lambda 950 UV-Vis-NIR spectrophotometer. Before testing, the scanning wavelength range was set to 200-2500 nm, the scanning step size was 1 nm, and the scanning speed was 600 nm / min. Baseline calibration was performed using a blank substrate (such as blank ITO glass or blank PET film) that was consistent with the sample substrate. The substrate's own absorption was subtracted. The test environment was controlled at room temperature of 25±2℃, relative humidity of 50±5%, and no strong light interference. During the test, the blank substrate was first placed in the sample holder for calibration. Then, each test sample (Examples 1-3 and Comparative Examples 1-3) was fixed in the sample holder, ensuring that the film surface was flat, free of dust and wrinkles. The scanning program was started to record the absorbance data of each band. Finally, the average absorbance of the full band (200~-2500 nm), the visible band (400-760 nm), and the near-infrared band (760-2500 nm) was extracted.

[0061] Table 1. Results of light absorption test

[0062] Experimental Example 2 The photothermal conversion capabilities of the composite thin film materials in Examples 1-3 and the thin film materials in Comparative Examples 1-3 were tested. A test system was constructed using an SS-F5-3A solar simulator (AM 1.5G standard spectrum), a FLIR E60 infrared thermometer, a Mettler PL2002 electronic balance, and an insulating ceramic support. The light source intensity was set to 100 mW / cm². 2 The test environment was room temperature 25±2℃, relative humidity 50±5% and no wind. The test time was 30 minutes (the stability standard was ≤1℃ difference between two consecutive temperature records). All samples were uniformly set to 2cm×2cm to ensure consistent light-receiving area. During the test, the mass of each sample was first weighed using an electronic balance. The samples were then fixed on an insulating ceramic support with the light-receiving surface facing the solar simulator (50cm away). The initial temperature (25℃) was recorded, and the solar simulator was turned on. The surface temperature was recorded every 5 minutes. After the temperature stabilized for 30 minutes, the photothermal conversion efficiency was calculated using the following formula: Where m is the sample mass (g); c is the specific heat capacity: 1.2 J / (g·℃); T1 is the stable temperature (℃); T0 is the initial temperature, i.e., 25℃; and S is the light-receiving area, i.e., 4 cm². 2 P represents the light source intensity, i.e., 100 mW / cm². 2 t represents the test time, which is 1800s.

[0063] Test results show that the photothermal conversion efficiencies of Examples 1-3 are 91.5%, 90.8%, and 90.2%, respectively, which are significantly higher than those of Comparative Example 1 (85.3%), Comparative Example 2 (86.7%), and Comparative Example 3 (82.1%). This indicates that the composite thin film material of the present invention can efficiently convert absorbed sunlight into heat energy and has excellent photothermal conversion performance.

[0064] Experimental Example 3 The composite film materials in Examples 1-3 and the film materials in Comparative Examples 1-3 were subjected to stability tests using a Shanghai Yiheng LHH-150S aging test chamber (with built-in LED simulated sunlight, intensity 100mW / cm²). 2 The tests were conducted using a PerkinElmer Lambda 950 UV-Vis-NIR spectrophotometer and an SS-F5-3A solar simulator. The test environment was controlled with a nitrogen protective atmosphere, a room temperature of 25±2℃, and a relative humidity of 50±5%. The test cycle was set to 1000h, with test intervals of 0h, 200h, 400h, 600h, 800h, and 1000h. All samples were not additionally encapsulated to simulate actual application scenarios. Before the test, the initial (0h) full-band absorptivity and photothermal conversion efficiency of each sample were measured as baseline data. Then, the samples were placed in an aging test chamber with the LED light source and nitrogen protection turned on. The samples were taken out at set intervals and allowed to stand at room temperature for 30min to recover to the ambient temperature. The full-band absorptivity and photothermal conversion efficiency were tested again, and the retention rate at each time point was calculated (retention rate = repeated test value / initial test value × 100%).

[0065] Test results show that after 1000 hours of long-term illumination, the composite films of Examples 1-3 retained 88.3%, 87.5%, and 86.9% of the full-band absorption rate, respectively; and 87.6%, 86.9%, and 86.5% of the photothermal conversion efficiency, respectively. In contrast, the comparative examples show that after 1000 hours, Comparative Example 1 retained only 72.4% of the full-band absorption rate and 69.8% of the photothermal efficiency; Comparative Example 2's retention rate dropped to 65.8% and 65.8% respectively; and Comparative Example 3's retention rate was only 68.5% and 68.5% respectively. Therefore, this invention effectively avoids the degradation and performance decay of the light-absorbing structure under long-term illumination, enabling the composite film material to simultaneously achieve a dual improvement in both "light absorption stability" and "photothermal stability."

[0066] Experiment Example 4 Roughness tests were conducted on the composite thin film materials in Examples 1-3 and the thin film materials in Comparative Examples 1-3. A Bruker Dimension Icon atomic force microscope (AFM) was used in tapping mode for the tests. A silicon probe (spring constant 40 N / m, resonant frequency 300 kHz) was selected. The scanning range was set to 5 μm × 5 μm (selecting the central area of ​​the sample to avoid edge effects), and the scanning resolution was 512 × 512 pixels. The test environment was controlled at room temperature 25 ± 2℃ and relative humidity below 40% (to avoid moisture affecting probe accuracy). During the test, each sample was first fixed on the AFM sample stage to ensure that the film surface was flat and free of impurities. Then, three different areas were selected at the center of each sample for scanning. The scanning time for each area was 10 min. The arithmetic mean roughness (Ra) was recorded, and the average value of the three areas was taken as the final result.

[0067] Test results show that the surface roughness of Examples 1-3 are 2.1 nm, 2.3 nm, and 1.9 nm, respectively, which are much lower than those of Comparative Example 1 (5.7 nm) and Comparative Example 3 (8.3 nm). Comparative Example 2 could not be used due to film cracking caused by the lack of organic polymer support. This indicates that the present invention significantly improves the interfacial compatibility between the organic and inorganic phases through the bridging effect of the surface modifier, inhibits the aggregation of inorganic nanosheets, and makes the film surface smoother and denser.

[0068] Therefore, this invention employs the aforementioned composite thin film material, its preparation method, and its application. By precisely selecting inorganic semiconductor nanomaterials and organic conjugated polymers, a light absorption system covering the entire ultraviolet-visible-near-infrared band is constructed. Simultaneously, by innovatively introducing 3-aminopropyltriethoxysilane as a surface modifier, the key problems of easy aggregation of inorganic phases and numerous interface defects in traditional organic-inorganic composite thin films are effectively solved, providing structural assurance for the stable performance of the material's light absorption and photothermal conversion properties.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A composite thin film material, characterized in that, The preparation raw materials include the following parts by weight: 5-20 parts of inorganic semiconductor nanomaterials, 75-90 parts of organic conjugated polymers, and 1-5 parts of surface modifiers; Among them, the inorganic semiconductor nanomaterial is selected from tungsten disulfide nanosheets or molybdenum disulfide nanosheets; the organic conjugated polymer is selected from poly(3-hexylthiophene-2,5-diyl) or poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]; and the surface modifier is 3-aminopropyltriethoxysilane.

2. The composite thin film material according to claim 1, characterized in that, The diameter of inorganic semiconductor nanomaterials is 50-200 nm, and the thickness is 1-5 nm.

3. The method for preparing the composite thin film material according to claim 1 or 2, characterized in that, Includes the following steps: (1) Inorganic semiconductor nanomaterials, surface modifiers and solvents are mixed and reacted to obtain a dispersion; (2) Mix the dispersion and the organic conjugated polymer solution to obtain the precursor solution; (3) The precursor solution is applied to the substrate surface and annealed to obtain the composite film material.

4. The method for preparing the composite thin film material according to claim 3, characterized in that, In step (1), the solvent is ethanol, and the ratio of the mass of the inorganic semiconductor nanomaterial to the volume of the solvent is 1 mg: 1-2 mL.

5. The method for preparing the composite thin film material according to claim 3, characterized in that, In step (1), the reaction temperature is 60-80℃ and the time is 2-4h.

6. The method for preparing the composite thin film material according to claim 3, characterized in that, In step (1), after the reaction is completed, the modified inorganic nanomaterials are obtained and dispersed in chlorobenzene to obtain a dispersion; the concentration of the modified inorganic nanomaterials in the dispersion is 5-10 mg / mL.

7. The method for preparing the composite thin film material according to claim 3, characterized in that, In step (2), the solvent for the organic conjugated polymer solution is chlorobenzene, and the concentration of the organic conjugated polymer in the organic conjugated polymer solution is 10-20 mg / mL.

8. The method for preparing the composite thin film material according to claim 3, characterized in that, In step (3), the coating method is spin coating, the spin coating speed is 3000-5000 rpm, and the time is 30-45s.

9. The method for preparing the composite thin film material according to claim 3, characterized in that, In step (3), the annealing temperature is 80-120℃ and the time is 10-30min.

10. The application of the composite thin film material according to claim 1 or 2, or the composite thin film material prepared by the preparation method according to any one of claims 3-9, in solar light absorption.

Images