Anti-reflection light trapping colloid based on laser ablated nano-powder as well as preparation method and application of anti-reflection light trapping colloid

Abstract

The invention relates to the technical field of nano materials and optical functional coatings, and discloses an anti-reflection light trapping colloid based on laser ablated nano powder as well as a preparation method and application of the anti-reflection light trapping colloid. The method comprises the following steps: ablating a raw material by laser to obtain nano powder with uniform particle size distribution and an oxide layer on the surface; mixing the nano powder with a solvent, a dispersing agent and / or a surfactant, and performing dispersion treatment to form stable colloid; and coating the colloid on the surface, interface or middle layer of a target device, and drying to form an antireflection and light trapping functional layer. The colloid can be used for photovoltaic solar cells, light emitting diodes (LEDs), intelligent glasses, chips, sensors and other photoelectric devices. The preparation method is simple in process and controllable in cost, the prepared colloid is stable and uniform in dispersion, interface carrier recombination is effectively inhibited through the oxide layer on the surface of the nano-powder, the problem that an existing plasma nano-structure preparation technology is high in cost is solved, and the preparation method is suitable for large-scale production and has a remarkable industrialization prospect.

Description

Technical Field

[0001] This invention relates to the field of nanomaterials and optical functional coatings, specifically to a method for preparing nanopowders based on laser ablation, dispersing the nanopowders in a solvent using a dispersant / surfactant to form a colloid, and coating it onto the surface / interface / intermediate layer of a target device to achieve its application in the fields of antireflection and light trapping. Background Technology

[0002] In optoelectronic devices such as solar cells, light-emitting diodes (LEDs), smart glasses, and optical sensors, surface light reflection is one of the key factors degrading performance. To improve device performance, developing efficient anti-reflection and light-trapping functional layers is crucial.

[0003] In recent years, crystalline silicon solar cell technology has made continuous progress, and the industry as a whole has continued to increase its R&D investment. However, the average annual increase in photoelectric conversion efficiency has dropped to about 0.5%, with a relative improvement rate of less than 2.5%. As efficiency approaches its theoretical limit, further improvements face enormous challenges. For a long time, the main paths to reduce manufacturing costs have included reducing the amount of silicon material used (thinning the silicon wafer), optimizing anti-reflection and light-trapping structures, and improving the internal quantum efficiency of the cell. Currently, the thickness of mainstream silicon wafers has been reduced to about 120 micrometers; further thinning will significantly increase the breakage rate, affecting yield and reliability.

[0004] Traditional antireflection and light-trapping techniques primarily rely on acid-base wet etching to construct pyramidal or random micro / nano structures on silicon surfaces. However, this process involves the loss of several micrometers of silicon material, and the structural morphology is significantly affected by crystal orientation, limiting uniformity and controllability. Furthermore, after decades of development, these surface texturing techniques have matured, leaving limited room for further optimization.

[0005] To overcome these bottlenecks, researchers proposed using plasmonic nanostructures to achieve efficient light management. Theoretical and experimental studies have shown that metal nanoparticles can effectively modulate the light field distribution through localized surface plasmon resonance (LSPR), plasmon coupling, and light scattering effects, thereby enhancing the light absorption of devices in the visible to near-infrared band and improving the external quantum efficiency of optoelectronic devices such as solar cells and LEDs.

[0006] However, existing methods for fabricating plasma nanostructures generally face obstacles to industrialization. For example, micro-nano fabrication techniques such as nanoimprinting and photolithography combined with reactive ion etching offer high precision, but the equipment is expensive, the processes are complex, and the production efficiency is low, making them unsuitable for large-area, low-cost device manufacturing. While the anodic aluminum oxide (AAO) template method can achieve periodic arrays, the template preparation has poor repeatability, making it difficult to ensure batch consistency. On the other hand, the method of forming nanoparticles by vacuum deposition of metal thin films followed by thermal annealing is moderately costly, but the particle size and distribution are difficult to control, resulting in poor repeatability.

[0007] More importantly, if metal nanoparticles come into direct contact with semiconductor materials, a Schottky barrier is easily formed at the interface, leading to an increase in carrier recombination rate and consequently reducing device performance. Therefore, although plasma-enhanced technology has been widely validated in academia, it has not yet been practically applied in the commercial production of solar cells.

[0008] To address the aforementioned problems, this invention proposes a novel colloid preparation method. This method utilizes laser ablation of raw materials in an air atmosphere to synthesize uniform nanoparticles with a narrow particle diameter distribution and a surface oxide layer. These nanoparticles are then dispersed into a stable colloid, and a functional layer is formed through a simple coating process. This method not only achieves high uniformity and good dispersibility of the nanoparticles but also effectively isolates the metal-semiconductor interface through the surface oxide layer, suppressing interfacial recombination. Furthermore, the entire process requires no complex equipment, making it suitable for large-scale production. It significantly reduces the preparation cost and process variability of the plasma functional layer, solving the three core challenges of high cost, low repeatability, and interfacial loss in existing technologies. Summary of the Invention

[0009] This invention provides a method for preparing a colloid and its antireflection and light-trapping applications. Through innovative laser ablation and colloidal chemical dispersion techniques, this invention prepares a nanocolloid with uniform particle size distribution and controllable surface properties. This colloid can be uniformly coated onto the surface of various devices to form a nanoparticle array layer with specific functions. Utilizing its localized surface plasmon resonance (LSPR), plasmon effect, and light scattering effect, it achieves excellent antireflection and light-trapping performance, thereby effectively improving the optoelectronic performance of the device.

[0010] To achieve the above-mentioned objectives, the technical solution of the present invention is as follows: This invention provides a method for preparing a colloid and its antireflection / light-trapping application, comprising the following steps: Laser ablation of raw materials produces nanoparticles with uniform particle size distribution and an oxide layer on the surface. The above-mentioned nanoparticles were uniformly dispersed in a solvent using a dispersant / surfactant to form a colloid.

[0011] The colloid is coated onto the surface, interface, or intermediate layer of the target device and dried to form an anti-reflection and light-trapping functional layer.

[0012] Furthermore, the laser can be a continuous laser or a pulsed laser.

[0013] Furthermore, the raw materials in step (1) are selected from at least one of the following substances: metals (silver, niobium, manganese, nickel, molybdenum, iron, tungsten, titanium, vanadium, copper, aluminum, magnesium, zinc, bismuth, zirconium), non-metals (silicon, carbon), rare earth elements (cerium), and alloys, compounds, or composite materials of the above elements. In particular, the method of the present invention can directly utilize the residues and waste generated during the industrial processing of the above materials as raw materials, realizing the recycling of resources and further reducing costs.

[0014] Typical process parameters for laser ablation are as follows: In an air atmosphere, a 500-watt pulsed laser cleaner is used to focus the laser onto the surface of a mixture of silicon particles (purity above 99%) and silicon residue through quartz glass. The laser scanning linewidth is 10-300 mm, and the scanning speed is 10 mm / s - 10 m / s. In this invention, different equipment may use different process parameters, which can be selected according to actual needs.

[0015] Furthermore, typical aqueous colloid components include solvent water (1 L), nanoparticles (0.1-10 g), sodium polyacrylate (0-5 g), PVP (0-2 g), PVA (0-2 g), Tween-80 (0-2 g), and silane coupling agent (0-10 g). The amount of each component in the colloid is adjusted accordingly as the nanoparticle content increases to maintain stable dispersion of the system. During preparation, dispersants, surfactants, and other auxiliary agents must be added in a specific order, and the pH of the system is adjusted to a suitable range using a buffer solution. Finally, a combination of mechanical stirring and ultrasonic stirring is used to ensure uniform mixing and the formation of a stable colloid.

[0016] Furthermore, the colloidal coating method includes at least one of dip coating, spray coating, roller coating, blade coating, slot coating, roll-to-roll coating, and inkjet printing. The appropriate method can be flexibly selected based on the size and shape of different devices.

[0017] Furthermore, the prepared colloid can be directly coated onto any surface, interface, or intermediate layer before encapsulation of solar cell modules, such as: the cell surface before deposition of the antireflection layer, the surface after deposition of the antireflection layer and before deposition of the electrode, and the cell surface after deposition of the electrode. It can also be coated onto any intermediate layer before encapsulation of LEDs, smart glasses, chips, and sensors to achieve antireflection and light trapping performance, thereby improving device efficiency or its low-light performance.

[0018] Furthermore, the drying process after coating is simple and efficient. It can be air-dried naturally at room temperature in a fume hood, or accelerated drying can be achieved by placing it in a drying oven or desiccant. The drying time can be controlled within 5 to 30 minutes depending on the coating thickness and process requirements.

[0019] The method described in this invention and the resulting colloid can be widely used in optoelectronic devices such as solar cells, LEDs, smart glasses, chips, and sensors.

[0020] Compared with the prior art, the advantages and beneficial effects of the present invention are: This invention innovatively solves the problems of reproducibility and carrier recombination: It fabricates nanoparticles with narrow particle size distribution and an oxide layer on the surface in a one-step laser ablation method. This oxide layer not only ensures the dispersion stability of the nanoparticles in the colloid and the reproducibility of the process, but more importantly, when applied to semiconductor devices (such as solar cells), the oxide layer acts as a physical isolation layer, effectively preventing direct contact between the metal nanoparticles and the semiconductor substrate. This significantly suppresses carrier recombination losses at the interface, a deficiency that existing direct deposition techniques for metal nanostructures struggle to overcome.

[0021] The process is simple, low-cost, and easy to scale up: The preparation process of this invention is short, does not rely on expensive vacuum equipment, and can be completed using laser equipment that is already maturely applied in industry; it can directly use industrial waste and residues as raw materials, realizing "turning waste into treasure", and has extremely high cost-effectiveness and the potential for large-scale production.

[0022] Excellent performance: Experiments show that the functional layer prepared by the method of this invention can achieve an anti-reflection effect of up to 10%, which can significantly improve the device efficiency and has significant application value and market prospects. Attached Figure Description

[0023] Figure 1 This is a scanning electron microscope image of the colloidal coating applied to the silicon surface in Example 1.

[0024] Figure 2 These are the reflectance spectra of the colloidal coated silicon wafer and the reference silicon wafer in the 400-1200nm spectral range in Example 1.

[0025] Figure 3 This is a scanning electron microscope image of the colloidal coating applied to the silicon surface in Example 2.

[0026] Figure 4 It is the reflectance of the colloidal coated silicon wafer and the reference silicon wafer in the 400-1200nm spectral range in Example 2.

[0027] Figure 5 It is the reflectance of the colloidal coated silicon wafer and the reference silicon wafer in the 400-1200nm spectral range in Example 3.

[0028] Figure 6 This is a transmission electron microscope image of the nanoparticles in Example 4.

[0029] Figure 7It is the reflectance of the colloidal coated silicon wafer and the reference silicon wafer in the 400-1200nm spectral range in Example 4.

[0030] Figure 8 It is the reflectance of the colloidal coated silicon wafer and the reference silicon wafer in the 400-1200nm spectral range in Example 5.

[0031] Figure 9 It is the reflectance of the colloidal coated silicon wafer and the reference silicon wafer in the 400-1200nm spectral range in Example 6.

[0032] Figure 10 It is the reflectance of the colloidal coated silicon wafer and the reference silicon wafer in the 400-1200nm spectral range in Example 7.

[0033] Figure 11 It is the reflectance of the colloidal coated silicon wafer and the reference silicon wafer in the 400-1200nm spectral range in Example 8.

[0034] Figure 12 It is the reflectance of the colloidal coated silicon wafer and the reference silicon wafer in the 400-1200nm spectral range in Example 9. Detailed Implementation

[0035] The following embodiments better illustrate the content of the present invention. However, the present invention is not limited to the following embodiments. Example 1

[0036] Preparation of silicon-based antireflective photocolloids and their application in solar cells. Specific steps are as follows: (1) Preparation of nanoparticles: A mixture of high-purity silicon particles and silicon processing residues was used as raw material. A 500W pulsed laser cleaning machine was used to focus the laser beam on the surface of the raw material for ablation in an air atmosphere. The key process parameters were set as follows: laser power 500W, scanning linewidth 10-300 mm, scanning speed 5 mm / s-5 m / s, and continuous scanning for 100 hours. After ablation, silicon-based nanoparticles with a natural oxide layer on the surface and uniform particle size distribution were collected.

[0037] (2) Colloid preparation: Measure 10 L of deionized water as solvent. Weigh 0.1-30 g of the nanoparticles obtained in step (1), and add 0.01-5 g of dispersant sodium hexametaphosphate, 0.01-2 g of sodium polyacrylate, and 0.01-1 g of surfactant polyvinylpyrrolidone (PVP) and Tween-80 in sequence. Use a buffer solution to adjust the pH of the mixture to a stable range of 7-9. During the addition process, after each additive is added, perform thorough mechanical stirring. After all the materials are added, perform ultrasonic dispersion treatment under ice bath conditions (power 500W, time 30 minutes) to prevent the nanoparticles from agglomerating due to temperature rise, and finally obtain a uniformly dispersed and stable silica-based colloid.

[0038] (3) Coating and Application: Commercially available monocrystalline silicon wafers and homogeneous solar cells are selected and cut into standard test sizes (wafers approximately 10 cm², cells 5-12 cm²). Using a dip-coating method, a portion of the silicon wafer and cell is immersed in the aforementioned colloid for 0.5-5 minutes. After removal, they are dried in a fume hood / drying oven for 10-20 minutes, thus forming an anti-reflective light-trapping functional layer on the surface.

[0039] (4) Performance characterization Morphological analysis: such as Figure 1 The scanning electron microscope (SEM) images show that a dense and uniform array of nanoparticles was formed on the surface of the colloidal coated silicon wafer, with the particle diameter concentrated at around 10 nm, proving that the method can achieve the controllable construction of nanostructures.

[0040] Optical performance: Reflectance was measured using a Perkin Elmer ultraviolet-visible-near-infrared spectrophotometer. For example... Figure 2 As shown, compared with the uncoated reference silicon wafer (curve "Si Reference"), the samples coated with colloids with different dip-coating parameters (corresponding to curves "Si 30s", "Si 1min", "Si 2min") showed a significant reduction in reflectance in the spectral range of 400-1000 nm, with the maximum reduction exceeding 10%, verifying the excellent broadband antireflection capability of this functional layer.

[0041] Electrical Performance: Under standard test conditions (AM 1.5G, 100 mW / cm²), the electrical performance of the solar cell was tested using a solar simulator and a source measurement unit. The short-circuit current (I_sc) of the uncoated reference cell was 235.3 mA, and the open-circuit voltage (V_oc) was 650.0 mV. After coating with the colloid, the I_sc increased to 244.8 mA (a relative increase of nearly 4.04%), and the V_oc increased to 650.9 mV. Overall, the photoelectric conversion efficiency of the cell increased by nearly 4.3%. This result directly confirms that the functional layer formed by the colloid of this invention improves light-harvesting efficiency while effectively suppressing interfacial carrier recombination due to the natural oxide layer on the surface of the nanoparticles, thus achieving synergistic gains in current and voltage. Example 2

[0042] Preparation of cerium oxide + titanium oxide-based antireflective optical composite colloids and their applications. Specific steps are as follows: (1) Preparation of nanopowder: A mixture of cerium oxide (CeO2) and titanium dioxide (TiO2) powder was used as raw material, wherein the mass ratio of TiO2 was 0.1%-50%. In an air atmosphere, a 2000W continuous laser cleaning machine was used, with the laser power set to 2000W, the scanning line width set to 50-300 mm, and the scanning speed set to 5 mm / s-2 m / s, to continuously ablate the raw material for 3 hours to obtain composite nanopowder.

[0043] (2) Colloid preparation: Measure 1 L of deionized water. Weigh 0.1-10 g of the above composite nanoparticles, and add sodium polyacrylate (0.01-2.5 g) as a dispersant, and PVP (0.01-2 g) and Tween-80 (0.01-1 g) as surfactants. Adjust the pH to a stable range using a buffer solution, and disperse the particles sequentially by stirring and ultrasonication in an ice bath to form a uniform and stable composite colloid.

[0044] (3) Coating and testing: Using the same dip coating process and drying conditions as in Example 1, the colloid was coated onto the surface of the silicon wafer to form a functional layer.

[0045] (4) Performance characterization Morphological analysis: such as Figure 3 The SEM images show that the prepared composite nanoparticles are uniformly distributed on the silicon wafer surface, with particle sizes mainly concentrated in the 10-20 nm range, further demonstrating the universality of laser ablation for preparing uniform nanoparticles from different raw materials. Optical properties: Reflectivity test results ( Figure 4 The results showed that the silicon wafer coated with this composite colloid had a reflectance reduction of more than 13% in the 400-1000 nm wavelength band compared to the reference sample. Example 3

[0046] Preparation of manganese-based antireflective optical colloids and their applications. Specific steps are as follows: (1) Preparation of nanoparticles: Manganese particles with a particle size of 0.1 mm-1 cm were used as raw materials. A 300W pulsed laser cleaning machine was used to ablate the raw materials in an air atmosphere. The key process parameters were set as follows: laser power 230W, scanning linewidth 50-200 mm, scanning speed 10 mm / s-10 m / s, and continuous ablation for 8 hours. After ablation, manganese-based nanoparticles with surface oxidation were collected.

[0047] (2) Colloid preparation: Measure 10 L of deionized water as a solvent. Weigh 0.1-10 g of the nanoparticles obtained in step (1), and add 0.01-3 g of dispersant sodium hexametaphosphate, 0.01-5 g of sodium polyacrylate, and 0.01-2 g of surfactant polyvinylpyrrolidone (PVP) in sequence. A special buffer solution is also needed to adjust the pH value to a suitable value. Add the dispersant in sequence and stir. A uniform colloid is formed.

[0048] (3) Coating and performance characterization: The colloid was coated onto the silicon wafer surface using the same dip-coating process as in Example 1, and then dried to form a functional layer. The optical reflectivity test results are as follows: Figure 5 As shown, in the wavelength range of 400-1000 nm, the reflectivity of the silicon wafer coated with manganese-based colloid is reduced by about 4% compared with the uncoated reference sample, confirming that manganese-based nanoparticles also have anti-reflection function. Example 4

[0049] Preparation of vanadium-based antireflection colloids and their applications. Specific steps are as follows: (1) Preparation of nanopowder: Vanadium particles or bulk materials with a size of 1 mm-3 cm were used as raw materials. A 300W pulsed laser cleaning machine was used, with the laser power set to 300W, the scanning line width set to 50-300 mm, and the scanning speed set to 10 mm / s-10 m / s. The particles were continuously ablated in air for 20 hours to obtain vanadium-based nanopowder.

[0050] (2) Colloid preparation: Measure 10 L of deionized water. Weigh 0.1-20 g of the above nanoparticles, and add sodium hexametaphosphate (0.01-3 g), sodium polyacrylate (0.01-5 g), and PVP (0.01-2 g) in sequence. Adjust the pH value to a suitable value with a special buffer solution, add the dispersant in sequence, and stir. A uniform colloid is formed.

[0051] (3) Coating and performance characterization: The functional layer was prepared using a standard dip-coating process. Transmission electron microscopy (TEM) analysis ( Figure 6 The results show that the obtained vanadium-based nanoparticles are mainly distributed below 20 nm in size and have uniform particle size. Reflectance test results ( Figure 7The results show that silicon wafers coated with this functional layer have a reflectivity reduction of about 7% in the 400-1000 nm wavelength band, demonstrating a significant anti-reflection effect. Example 5

[0052] Preparation of tungsten-based antireflective optical colloids and their applications. Specific steps are as follows: (1) Preparation of nanopowder: Commercial tungsten powder was used as raw material. A 300W pulsed laser cleaning machine was used, with the laser power set to 210W, the scanning line width set to 50-300 mm, and the scanning speed set to 10 mm / s-5 m / s. The nanopowder was prepared by ablation in air atmosphere for 8 hours.

[0053] (2) Colloid preparation: Measure 10 L of deionized water. Weigh 0.5-30 g of nanoparticles and add sodium hexametaphosphate (0.01-3 g), sodium polyacrylate (0.01-5 g), PVP (0.01-2 g), and Tween-80 (0.01-1 g). Adjust the pH value to a suitable value using a special buffer solution, add the dispersant sequentially, and stir. A homogeneous colloid is formed.

[0054] (3) Coating and performance characterization: After coating and drying, reflectivity was tested. Figure 8 The results showed that silicon wafers coated with tungsten-based colloids exhibited a more than 3% reduction in reflectivity within the 400-1000 nm wavelength range. Example 6

[0055] Preparation of bismuth-based antireflection colloids and their application in solar cells. Specific steps are as follows: (1) Preparation of nanopowder: Bismuth plates, bismuth blocks or bismuth particles are used as raw materials. A 300W pulsed laser cleaning machine is used, with the laser power set to 200W, the scanning line width set to 50-300 mm, and the scanning speed set to 10 mm / s-5 m / s. The nanopowder is obtained by ablation in air atmosphere for 10 hours.

[0056] (2) Colloid preparation: Measure 10 L of deionized water. Weigh 0.5-30 g of nanoparticles, add sodium hexametaphosphate (0.01-3 g), sodium polyacrylate (0.01-5 g), PVP (0.01-6 g), and Tween-80 (0-1 g). Adjust the pH value to a suitable value with a special buffer solution, add the dispersant in sequence, and stir. Form a homogeneous colloid.

[0057] (3) Coating and performance characterization: Coated onto the surface of the solar cell using standard processes. Reflectivity test ( Figure 9The results show that this functional layer reduces the reflectivity of the silicon wafer by more than 5% in the 400-1000 nm wavelength range. Electrical performance tests show that the short-circuit current of the battery increased from 223.3 mA to 230.7 mA after coating, a relative increase of 3.3%, directly proving the effective gain of this functional layer on the battery photocurrent. Example 7

[0058] Preparation of tin-based antireflective optical colloids and their applications. Specific steps are as follows: (1) Preparation of nanopowder: using tin plates, tin blocks or tin particles as raw materials. A 2000W continuous laser cleaning machine was used, with the laser power set to 2000W, the scanning line width set to 50-300 mm, and the scanning speed set to 10 mm / s-10 m / s. The tin-based nanopowder was obtained by continuous ablation in air atmosphere for 100 hours.

[0059] (2) Colloid preparation: Measure 10 L of deionized water. Weigh 0.5-30 g of nanoparticles, add sodium hexametaphosphate (0.01-3 g), sodium polyacrylate (0.01-5 g), PVP (0.01-2 g), and Tween-80 (0-1 g). Adjust the pH value to a suitable value with a special buffer solution, add the dispersant sequentially, and stir. Form a homogeneous colloid.

[0060] (3) Coating and performance characterization: Coating test results ( Figure 10 The data shows that tin-based functional layers can reduce the reflectivity of silicon wafers by more than 5% in the 400-1000nm wavelength range. Example 8

[0061] Preparation of tungsten-copper-based antireflective optical colloids and their applications. Specific steps are as follows: (1) Preparation of nanopowder: Tungsten copper alloy blocks or alloy powders were used as raw materials. A 2000W continuous laser cleaning machine was used, with the laser power set to 2000W, the scanning line width set to 50-300 mm, and the scanning speed set to 10 mm / s-3 m / s. The nanopowder was ablated in air for 8 hours to obtain tungsten copper composite nanopowder.

[0062] (2) Colloid preparation: Measure 10 L of deionized water. Weigh 0.5-30 g of nanoparticles, add sodium hexametaphosphate (0.01-3 g), sodium polyacrylate (0.01-5 g), PVP (0.01-8 g), and Tween-80 (0-1 g). Adjust the pH value to a suitable value with a special buffer solution, add the dispersant in sequence, and stir. Form a uniform colloid.

[0063] (3) Coating and performance characterization: Reflectivity test results ( Figure 11The results show that silicon wafers coated with this composite colloid have a reflectivity reduction of more than 8% in the 400-1000 nm wavelength band, demonstrating the synergistic enhancement potential of the alloy components in antireflection. Example 9

[0064] Preparation of nickel-based antireflective optical colloids and their applications. Specific steps are as follows: (1) Preparation of nanopowder: Nickel blocks or nickel particles are used as raw materials. A 2000W continuous laser cleaning machine is used, with the laser power set to 2000W, the scanning line width set to 50-300 mm, and the scanning speed set to 10 mm / s-3 m / s. The nickel-based nanopowder is obtained by continuous ablation in air atmosphere for 80 hours.

[0065] (2) Colloid preparation: Measure 10 L of deionized water. Weigh 0.5-30 g of nanoparticles, add sodium hexametaphosphate (0.01-3 g), sodium polyacrylate (0.01-5 g), PVP (0.01-8 g), and Tween-80 (0-1 g). Adjust the pH value to a suitable value with a special buffer solution, add the dispersant in sequence, and stir. Form a uniform colloid.

[0066] (3) Coating and performance characterization: Reflectivity test results ( Figure 12 The results showed that silicon wafers coated with nickel-based colloids exhibited a nearly 10% reduction in reflectivity within the 400-1000 nm wavelength range, achieving a significant anti-reflection effect.

[0067] As illustrated by the above embodiments, the performance of nanopowders can be adjusted by modifying powder-making parameters, including raw material composition and laser scanning parameters. A uniformly dispersed colloid can be prepared by modulating solvents and dispersants, and a surface nanoparticle array layer can be obtained by coating. This layer has anti-reflection and light-trapping functions, and can be widely used in solar cells, LEDs, smart glasses, and sensors.

[0068] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions claimed by the present invention.

Claims

1. A method for preparing a laser-ablation-nanopowder-based antireflection light-trapping colloid, characterized in that, The method comprises the following steps: (1) using laser ablation of raw materials to obtain nano-powder with uniform particle size distribution and surface oxide layer; (2) mixing the nano-powder with solvent, dispersant and / or surfactant, and forming a stable colloid after dispersion treatment; (3) coating the colloid on the surface, interface or intermediate layer of the target device, and forming a functional layer with anti-reflection and light trapping functions after drying.

2. The method of claim 1, wherein, The laser includes continuous laser and pulsed laser.

3. The method of claim 1, wherein, The raw material in step (1) is selected from at least one of silver, niobium, manganese, nickel, molybdenum, iron, tungsten, titanium, vanadium, copper, aluminum, magnesium, zinc, bismuth, zirconium, silicon, carbon, cerium; alloys, compounds and composite materials of the above elements; and also includes polishing, cutting and other waste materials generated during processing of the above materials.

4. The method of claim 1, wherein, The colloid composition contains the above nano-powder and further contains at least two of the following substances: water, alcohol, sodium polyacrylate, sodium gluconate, polyvinylpyrrolidone PVP, polyvinyl alcohol PVA, tween-80, silane coupling agent, BYK-110 dispersant, BYK-163 dispersant, sodium dodecyl sulfate and sodium hexametaphosphate.

5. The method of claim 1, wherein, The coating method includes dipping, spraying, rolling, scraping, slot coating, roll-to-roll and inkjet printing.

6. The method of claim 1, wherein, Step (3) can be applied to any surface, interface or intermediate layer before packaging of a solar cell assembly; it can also be used for the intermediate layer of any light emitting diode LED, smart glasses, chips and sensors.

7. The colloid prepared by the method of any one of claims 1 to 6 can be used to improve the anti-reflection and light trapping performance of solar cells, LEDs, smart glasses, chips and sensors, thereby improving the efficiency of the devices or improving their low light performance.

8. The colloid prepared by the preparation method of any one of claims 1-7 and its application.

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