A method for producing a layered structure silicon oxide film

Abstract

The application discloses a preparation method of a layered structure silicon oxide film, and belongs to the technical field of deep processing of glass thin film. First, monodisperse polystyrene microsphere emulsion is used as raw material, and 2-5 layers of ordered colloid crystal templates are prepared on a substrate through a doctor blade method. Then, tetraethyl orthosilicate is used as a precursor, hydrolysis and condensation are carried out under catalysis of a specific acid-base sequence, and an SiO2 coating sol is prepared by combining an anionic surfactant as a soft template. Finally, the sol is used as a coating liquid, the above template is used as the substrate, and a film is formed by adopting a spin coating or a pulling method, the template is removed through drying and heat treatment at 400-600 DEG C, and a silicon oxide film with a layered, through and multi-level pore structure is obtained. The method is simple and controllable, the prepared film has the characteristics of low refractive index and high optical transmittance, and has important application prospects in the field of solar photovoltaic cells.

Description

Technical Field

[0001] This invention belongs to the field of glass deep processing thin film preparation technology, specifically, it relates to a method for preparing a layered silicon oxide film. Background Technology

[0002] With the rapid development of photovoltaic and energy-efficient building technologies, the demand for high-performance optical thin films is also increasing. Microstructural control of thin film materials to prepare high-performance thin film materials is an emerging field in nanomaterials in recent years.

[0003] The core of this research lies in precisely constructing micro- and nano-structures to endow materials with special functions that planar thin films lack. The performance of thin film materials is highly coupled with their microstructure; therefore, the controllable fabrication of micro- and nano-structures is a key technological challenge in the field of glass deep-processing thin films. Artificially constructing microstructures for glass thin films is a core means of enhancing their optical, electrical, and thermal functionalities. Microstructured film surfaces can significantly increase specific surface area and strengthen interfacial interactions with the phase medium. This not only allows for the control of the incident angle through light scattering to achieve anti-reflection effects but also enables precise adjustment of surface wettability, achieving superhydrophilic or superhydrophobic properties. These advantages give it broad application potential in high-end fields such as solar cells. Among these, silicon oxide (SiO2) thin films, due to their excellent optical stability and chemical inertness, have become the preferred material for photovoltaic cover glass and other applications. Optimizing its surface microstructure is a core direction for improving anti-reflection, wettability, and mechanical properties.

[0004] Traditionally, silicon oxide thin films are mainly prepared using processes such as physical vapor deposition (PVD) or chemical vapor deposition (CVD). While these methods offer advantages in terms of film uniformity and density, the resulting film structures are often dense and non-porous or randomly porous, limiting improvements in optical performance, particularly in achieving low refractive indices, thus restricting their applications. Therefore, it is urgent to address these issues to enable silicon oxide thin films to be better utilized in the field of solar cells. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing a layered silicon oxide film.

[0006] The objective of this invention can be achieved through the following technical solutions: A method for preparing a layered silicon oxide film includes the following steps: S1. Using polystyrene microsphere emulsion as raw material, a scraping method is used to coat it onto a clean glass substrate. After the coating is completed, it is allowed to dry naturally at room temperature to obtain a few-layer colloidal crystal template. S2. Add anhydrous ethanol, tetraethyl orthosilicate and deionized water to the reaction vessel, mix well, heat the system to 30-60℃, add acid solution, adjust the pH of the system to 2-5, continue stirring for 1-3h, then add surfactant and alkaline solution, adjust the pH of the system to 7-9, and stir for another 1-3h to obtain SiO2 coating sol. S3. Using SiO2 coating sol as the coating solution and a few-layer colloidal crystal template as the substrate, the coating is carried out by spin coating or dip coating. After coating, the wet film is quickly dried and then transferred into a muffle furnace for heat treatment to obtain a layered silicon oxide film.

[0007] Furthermore, in step S1, the gap size of the coating bar in the coating method is 2-20 μm, and the coating speed is 1-5 m / min.

[0008] Furthermore, in step S1, the particle layer of the few-layer colloidal crystal template is 2-5 layers.

[0009] Furthermore, in step S1, the solid content of the polystyrene microsphere emulsion is 0.5-5.0 wt%, wherein the particle size of the polystyrene microspheres is 30-300 nm.

[0010] Furthermore, the surfactant in step S2 is an anionic surfactant.

[0011] Furthermore, in step S2, the acid solution is one of hydrochloric acid solution, boric acid solution, and sulfuric acid solution.

[0012] Furthermore, the alkaline solution in step S2 is ammonia.

[0013] Furthermore, the order of adding acid and alkali in step S2 can be changed. If alkali is added first, the pH of the system is adjusted to 7-9. After ammonia stripping, acid is added and the pH of the system is adjusted to 5-7.

[0014] Furthermore, in step S3, the spin coating speed is 1000-3000 rpm and the time is 10-30 s.

[0015] Furthermore, the lifting speed of the lifting method in step S3 is 0.5-2 mm / s.

[0016] Furthermore, the drying conditions in step S3 are drying in an oven at 100-200℃ for 0.5-2 hours.

[0017] Furthermore, the heat treatment conditions in step S3 are to raise the temperature to 400-600℃ at a rate of 2-5℃ / min and hold it at that temperature for 1-2 hours.

[0018] This invention first utilizes polystyrene microspheres to form a few-layer colloidal crystal template through precise coating. The orderly arranged microspheres not only provide a layered framework for the subsequent film but also define the deposition area and pore structure of silicon oxide. Using tetraethyl orthosilicate as a precursor, through hydrolysis and condensation, and by utilizing the dispersing effect of surfactants, sol particles can be uniformly filled into the gaps and surface of the template. After the third step of film deposition, heat treatment can completely oxidize and decompose the template, leaving layered macroporous channels that complement the template structure. This forms a layered silicon oxide film with both high specific surface area and structural stability. Its macroporous structure significantly reduces the refractive index and improves optical transmittance.

[0019] The beneficial effects of this invention are: 1. The thin film prepared by this invention has internal macropores and a layered structure. This special structure greatly reduces the refractive index of the thin film and can improve the optical transmittance of the substrate, which has important application prospects in the field of solar photovoltaic cells. 2. At the same time, this preparation method can also adjust the particle size of silica sol film, which has a certain regulatory effect on the microstructure and hardness of the film, thus broadening the application scenarios. Attached Figure Description

[0020] The invention will now be further described with reference to the accompanying drawings.

[0021] Figure 1 This is a SEM cross-sectional image of the few-layer colloidal crystal template prepared in Example 1 of the present invention.

[0022] Figure 2 This is a SEM cross-sectional image of the layered silicon oxide film prepared in Example 1 of the present invention.

[0023] Figure 3 This is a SEM image of the layered silicon oxide film obtained in Example 1 of the present invention. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1 A method for preparing a layered silicon oxide film includes the following steps: S1. Using a polystyrene microsphere emulsion with a solid content of 0.5wt% (the particle size of the polystyrene microspheres is 200nm) as raw material, a blade coating method is adopted (the gap size of the blade coating bar is 2μm, and the coating speed is 1m / min) to coat it on a clean glass substrate. After the coating is completed, it is naturally dried at room temperature to obtain a few-layer colloidal crystal template (2 layers). S2. Add 150 mL of anhydrous ethanol, 10 mL of tetraethyl orthosilicate and 5 mL of deionized water to the reaction vessel. After mixing evenly, heat the system to 40 °C, add hydrochloric acid solution (concentration 0.1 mol / L), adjust the pH of the system to 2, and continue stirring for 1 h. Then add sodium dodecyl sulfate and ammonia water, adjust the pH of the system to 7, and stir for another 1 h to obtain SiO2 coating sol. S3. Using SiO2 coating sol as the coating solution and a few-layer colloidal crystal template as the substrate, the coating was carried out by spin coating (1000 rpm, 10 s). After coating, the wet film was quickly placed in an oven and dried at 100°C for 2 h. Then it was transferred to a muffle furnace and heated to 400°C at a rate of 2°C / min for 1 h to obtain a layered silicon oxide film. The cross-section of the few-layer colloidal crystal template obtained in step S1 was observed using an electron microscope, and the resulting SEM image is shown below. Figure 1 As shown; further, the cross-section and surface of the layered silicon oxide film were observed, and the resulting SEM images are as follows. Figure 2 and Figure 3 As shown.

[0026] Example 2 A method for preparing a layered silicon oxide film includes the following steps: S1. Using a polystyrene microsphere emulsion with a solid content of 0.5wt% (the particle size of the polystyrene microspheres is 200nm) as raw material, a blade coating method is adopted (the gap size of the blade coating bar is 20μm, and the coating speed is 5m / min) to coat it on a clean glass substrate. After the coating is completed, it is naturally dried at room temperature to obtain a few-layer colloidal crystal template (2 layers). S2. Add 150 mL of anhydrous ethanol, 10 mL of tetraethyl orthosilicate and 5 mL of deionized water to the reaction vessel, mix well, heat the system to 40 °C, add ammonia water, adjust the pH of the system to 9, continue stirring for 1-3 h, then add sodium dodecyl sulfate and hydrochloric acid solution (concentration 0.1 mol / L), treat with ammonia stripping at 85 °C for 4 h, adjust the pH of the system to 5, and stir for another 3 h to obtain SiO2 coating sol; S3. Using SiO2 coating sol as the coating solution and a few-layer colloidal crystal template as the substrate, the coating was carried out by the Czochralski method (coiling speed of 2 mm / s). After coating, the wet film was quickly placed in an oven and dried at 200°C for 0.5 h. Then it was transferred to a muffle furnace and heated to 600°C at a rate of 5°C / min for 2 h to obtain a layered silicon oxide film.

[0027] This invention is from Figure 1 As can be seen, the polystyrene microspheres are arranged in an orderly manner on the glass substrate, and the overall layered stacked structure is clear. This template provides a structural basis for subsequent SiO2 sol filling. Figure 2 The film clearly shows a distinct layered stacked structure, with the layers arranged in parallel; from Figure 3 An ordered array of pores with uniform pore size and no obvious agglomeration can be observed on the surface of the thin film. In summary, the method of the present invention can indeed prepare a silicon oxide thin film with a layered, ordered, and porous structure, which has important application prospects in the field of solar photovoltaic cells.

[0028] In the description of this specification, references to terms such as "an embodiment," "example," and "specific example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0029] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A method for preparing a layered silicon oxide film, characterized in that, Includes the following steps: S1. Using polystyrene microsphere emulsion as raw material, a scraping method is used to coat it onto a clean glass substrate. After the coating is completed, it is allowed to dry naturally at room temperature to obtain a few-layer colloidal crystal template. S2. Add anhydrous ethanol, tetraethyl orthosilicate and deionized water to the reaction vessel, mix well, heat the system to 30-60℃, add acid solution, adjust the pH of the system to 2-5, continue stirring for 1-3h, then add surfactant and alkaline solution, adjust the pH of the system to 7-9, and stir for another 1-3h to obtain SiO2 coating sol. S3. Using SiO2 coating sol as the coating solution and a few-layer colloidal crystal template as the substrate, the coating is carried out by spin coating or dip coating, then dried and heat-treated to obtain a layered silicon oxide film.

2. The method for preparing a layered silicon oxide film according to claim 1, characterized in that, In step S1, the gap size of the coating bar in the coating method is 2-20 μm, and the coating speed is 1-5 m / min.

3. The method for preparing a layered silicon oxide film according to claim 1, characterized in that, In step S1, the particle layers of the few-layer colloidal crystal template are 2-5 layers.

4. The method for preparing a layered silicon oxide film according to claim 1, characterized in that, In step S1, the solid content of the polystyrene microsphere emulsion is 0.5-5.0 wt%, and the particle size of the polystyrene microspheres is 30-300 nm.

5. The method for preparing a layered silicon oxide film according to claim 1, characterized in that, The surfactant in step S2 is an anionic surfactant.

6. The method for preparing a layered silicon oxide film according to claim 1, characterized in that, The order of adding acid and alkali in step S2 can be changed. If alkali is added first, the pH of the system is adjusted to 7-9. After ammonia stripping, acid is added and the pH of the system is adjusted to 5-7.

7. The method for preparing a layered silicon oxide film according to claim 1, characterized in that, In step S3, the spin coating speed is 1000-3000 rpm and the time is 10-30 s.

8. The method for preparing a layered silicon oxide film according to claim 1, characterized in that, The lifting speed in step S3 is 0.5-2 mm / s.

9. The method for preparing a layered silicon oxide film according to claim 1, characterized in that, The drying conditions in step S3 are drying in an oven at 100-200℃ for 0.5-2 hours.

10. The method for preparing a layered silicon oxide film according to claim 1, characterized in that, The heat treatment conditions in step S3 are to raise the temperature to 400-600℃ at a rate of 2-5℃ / min and hold it at that temperature for 1-2 hours.

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