A method for preparing a high-performance SiO2 antireflection membrane

Abstract

This invention discloses a method for preparing a high-performance SiO2 antireflection film, comprising: preparing sol A and sol B using a simple and efficient sol-gel method; performing plasma cleaning on the substrate; and performing alternating deposition of the two sols multiple times using a dip-coating method to obtain a high-performance multilayer SiO2 antireflection film with high transmittance, high laser damage threshold, and good environmental stability in the wavelength range of 1000nm to 1100nm. The high-performance multilayer SiO2 antireflection film has eight layers. Sol A is prepared using an ammonia-catalyzed sol, which has high porosity, resulting in high transmittance of the deposited film. Sol B is prepared using a hexamethyldisilazane-modified sol. The surface layer deposited with hexamethyldisilazane-modified sol introduces a large number of nonpolar hydroxyl groups on the film surface, effectively preventing water vapor and organic pollutants from entering the film pores, thereby improving the film's environmental stability, laser damage resistance, and mechanical strength.

Description

Technical Field

[0001] This invention belongs to the field of optical technology, and more specifically, this invention relates to a method for preparing a high-performance SiO2 antireflection film. Background Technology

[0002] Since the invention of the laser in the last century, lasers have been widely used in various fields due to their excellent beam characteristics, playing a significant role in promoting the progress and development of human society. High-energy and high-power laser output technology is one of the important directions in the field of laser research today. In the optical components of high-power laser devices, optical elements commonly used in the near-infrared (fundamental frequency 1053nm and 1064nm) wavelength range include mirrors, lenses, and windows. Because it is necessary to convert the fundamental frequency laser into a third-harmonic laser, some optical components of the optical assembly need to withstand irradiation by high peak power lasers to meet the engineering applications of laser transmission and frequency conversion under high peak power or high average power conditions. With the continuous increase in the output laser energy density of high-power laser devices, the problem of damage to optical components under strong laser irradiation has emerged. Improving the load-bearing capacity of optical components under strong laser irradiation is a method to achieve high-energy output in high-power laser devices. Currently, a common method is to coat the surface of optical components with an anti-reflection coating to increase the transmittance of laser light while reducing laser damage to the optical components. Meanwhile, as laser output energy continues to increase, the surface of optical thin films will suffer severe laser damage, and traditional SiO2 antireflection films are susceptible to environmental pollution, which affects the antireflection effect of the film and leads to damage to optical components. Chinese invention patent application number 202211335660.6 discloses a method for preparing a silica antireflection film. This application discloses a preparation scheme for a 2-6 layer silica film. In a specific embodiment, an acid-catalyzed SiO2 sol and an alkali-catalyzed SiO2 sol are mixed as the raw material for the bottom layer film A, with a volume ratio of 1:4. HMDS / TEOS sol is used as the raw material for the top layer film B. Then, the bottom layer film A and the top layer film A are dip-coated to obtain a double-layer silica antireflection film. The high transmittance band of this double-layer silica antireflection film is concentrated at the center wavelengths of 351nm, 527nm, 1053nm, and 1064nm. Its transmittance in the 1000nm-1100nm wavelength range has room for improvement. Simultaneously, the laser damage threshold of this silica antireflection film is ≥20J / cm². 2 There is also room for improvement in the laser damage threshold. Therefore, it is necessary to prepare antireflective films with high transmittance at fundamental frequencies of 1053 nm and 1064 nm, as well as high resistance to laser damage, good environmental stability, and high mechanical strength. Summary of the Invention

[0003] One object of the present invention is to solve at least the above-mentioned problems and / or defects, and to provide at least the advantages described below.

[0004] To achieve these objectives and other advantages according to the present invention, a method for preparing a high-performance SiO2 antireflection film is provided, comprising:

[0005] First, the prepared sol A is dip-coated onto the substrate to form the first film, denoted as film A; then, sol B is dip-coated onto the surface of the first film to form the second film, denoted as film B. The above dip-coating sequence is repeated until an alternating 8-layer high-performance SiO2 antireflection film of A / B / A / B / A / B / A / B is formed.

[0006] Preferably, the process specifically includes the following steps:

[0007] Step 1: Take a certain proportion of tetraethyl orthosilicate, anhydrous ethanol, and ammonia, mix the three solutions and seal them in a reaction vessel, stir magnetically for a certain time under certain temperature conditions, and then age them at room temperature.

[0008] Step 2: The sol aged in Step 1 is refluxed and condensed at a certain temperature to remove ammonia, thus obtaining sol A;

[0009] Step 3: Take a certain proportion of anhydrous ethanol, ammonia, deionized water, hexamethyldisilazane, and tetraethyl orthosilicate, mix the five solutions and seal them in a reaction vessel, and stir magnetically for a certain time under certain temperature conditions, and then age them at room temperature.

[0010] Step 4: Take out a certain amount of the aged sol from Step 3, add an equal volume of anhydrous ethanol and mix well to obtain sol B;

[0011] Step 5: Soak the substrate in an ethanol / acetone mixture for ultrasonic cleaning for a certain period of time, then dry it by blowing.

[0012] Step 6: Perform plasma cleaning on the substrate using a PCE-6 plasma cleaner;

[0013] Step 7: First, use sol A to deposit a layer A film on the substrate, and then use sol B to deposit a layer B film.

[0014] Step 8: Repeat step 7 until 8 layers are deposited to obtain 8 high-performance SiO2 antireflection films.

[0015] Preferably, in step one, the volume ratio of tetraethyl orthosilicate, anhydrous ethanol, and ammonia is 1:1:0.5, the stirring temperature is 30°C, the stirring time is 12 hours, and the aging time is 12 hours.

[0016] Preferably, in step two, the reflux condensation temperature is 85°C and the reflux condensation time is 6 hours.

[0017] Preferably, in step three, the volume ratio of anhydrous ethanol, ammonia, deionized water, hexamethyldisilazane, and tetraethyl orthosilicate is 10:0.05:0.2:0.1:1.

[0018] Preferably, in step five, the ultrasonic cleaning time is 10 minutes.

[0019] Preferably, in step six, the plasma cleaning power is 30W and the cleaning time is 5 minutes.

[0020] Preferably, in step seven, the substrate is immersed in the sol for 5 seconds during the lifting coating process, and the lifting speed is 100 mm / min.

[0021] This invention offers at least the following advantages: First, two high-purity SiO2 sols with different physicochemical parameters are prepared using the sol-gel method. The substrate is then cleaned using a PEC-6 plasma cleaner. The two sols are then compositely deposited using a dip-coating method to prepare a multilayer SiO2 antireflection film with high transmittance, a high laser damage threshold, and good environmental stability. This antireflection film exhibits a transmittance >99.5% and a reflectance <0.4% in the near-infrared wavelength range of 1000nm–1100nm; it also possesses good hydrophobicity (water contact angle ≥120°) and a high laser damage threshold (threshold ≥40 J / cm²). 2 This high-performance multilayer SiO2 antireflective film outperforms traditional single-layer or double-layer SiO2 antireflective films in all performance indicators within the wavelength range of 1000nm to 1100nm, and is suitable for optical components in high-power laser devices such as mirrors, lenses, and windows with fundamental frequencies of 1053nm and 1064nm.

[0022] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0023] Figure 1 The transmittance diagram is for the high-performance 8-layer SiO2 antireflection film prepared in Example 1.

[0024] Figure 2 The reflectance diagram of the high-performance 8-layer SiO2 antireflection film prepared in Example 1;

[0025] Figure 3 The contact angle diagram of the high-performance 8-layer SiO2 antireflection film prepared in Example 1;

[0026] Figure 4 This is an adhesion test diagram of the high-performance 8-layer SiO2 antireflection film prepared in Example 1;

[0027] Figure 5 Laser damage attempt of the high-performance 8-layer SiO2 antireflection film prepared in Example 1;

[0028] Figure 6 The transmittance of the 8-layer SiO2 antireflection film prepared for Comparative Example 1 is shown in the diagram.

[0029] Figure 7 The reflectance diagram of the 8-layer SiO2 antireflection film prepared for Comparative Example 1. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0031] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0032] Example 1

[0033] This embodiment provides a method for preparing a high-performance SiO2 antireflection film, including the following steps:

[0034] Step 1: Take 10 mL of tetraethyl orthosilicate, 100 mL of anhydrous ethanol, and 0.5 mL of ammonia. Mix the above three solutions and seal them in a double-necked flask. Stir magnetically for 12 h at 30 °C, and then age at room temperature for 12 h.

[0035] Step 2: Refluxing and condensing the sol aged in Step 1 at 85°C for 6 hours to remove ammonia, thus obtaining sol A;

[0036] Step 3: Take 100 mL of anhydrous ethanol, 0.5 nL of ammonia, 2 mL of deionized water, 1 mL of hexamethyldisilazane, and 10 mL of tetraethyl orthosilicate. Mix the above 5 solutions and seal them in a double-necked flask. Stir magnetically at 30°C for 12 h, and then age at room temperature for 12 h.

[0037] Step 4: Take out a certain amount of the aged sol from Step 3, add an equal volume of anhydrous ethanol and mix well to obtain sol B;

[0038] Step 5: Soak the substrate in an ethanol / acetone mixture for ultrasonic cleaning for 10 minutes, then dry it by blowing.

[0039] Step 6: Perform plasma cleaning on the substrate using a PCE-6 plasma cleaner with a cleaning power of 30W and a cleaning time of 5 minutes.

[0040] Step 7: First, use sol A to deposit one layer on the substrate, and then use sol B to deposit a second layer. When lifting the coating, the substrate is immersed in the sol for 5 seconds and the lifting speed is 100 mm / min.

[0041] Step 8: Repeat step 7 until 8 layers are deposited to obtain 8 high-performance SiO2 antireflection films.

[0042] The high-performance SiO2 antireflection membrane sample prepared in this embodiment, such as Figure 1 As shown. The transmittance at the center wavelength of 1053 nm, measured by ultraviolet spectrophotometer, is 99.66%; as Figure 2 As shown, the reflectance measured by atomic force microscopy is 0.25%; Figure 3 As shown, the water contact angle measured by the water contact measuring instrument is 123°; Figure 4 As shown, the laser damage threshold obtained through tests such as 1064nm fundamental frequency laser damage is 43J / cm. 2 The film adhesion capability reaches level 5B.

[0043] Comparative Example 1

[0044] This comparative example provides a method for preparing a SiO2 antireflection film, including the following steps:

[0045] Step 1: Preparation of alkaline-catalyzed SiO2 sol. The specific method is as follows: Take 10 mL of tetraethyl orthosilicate, 100 mL of anhydrous ethanol and 0.5 mL of ammonia water and mix them to obtain a solution. Seal the solution in a 250 mL double-necked round-bottom flask and stir it at 30 °C for 12 h. Then place it at room temperature for aging for 12 h to obtain alkaline-catalyzed SiO2 sol, denoted as solC.

[0046] Step 2: Preparation of acid-catalyzed SiO2 sol. The specific method is as follows: Take 11 mL of tetraethyl orthosilicate, 110 mL of anhydrous ethanol and 4 mL of deionized water and mix them evenly. The deionized water contains 0.02 mL of concentrated hydrochloric acid to obtain a reaction solution. Seal the reaction solution in a 250 mL round bottom flask and stir it at 40 °C for 12 h. Then place it at room temperature for aging for 24 h to obtain acid-catalyzed SiO2 sol, denoted as solD.

[0047] Step 3: Prepare HMDS / TEOS sol. The specific method is as follows: Take 100 mL of anhydrous ethanol, 0.5 nL of ammonia water, 2 mL of deionized water, 1 mL of hexamethyldisilazane (HMDS) and 10 mL of tetraethyl orthosilicate (TEOS) and mix them. Add these reagents to a 250 mL round bottom flask and stir at 30 °C for 12 h. Then place it at room temperature for aging for 12 h. Add an equal volume of anhydrous ethanol and mix well to obtain HMDS / TEOS sol, denoted as solB.

[0048] Step 4: Mix solC and solD at a volume ratio of 1:9 to obtain an acid-base composite sol, denoted as solA; perform plasma cleaning on the substrate using a PCE-6 plasma cleaner with a cleaning power of 30W and a cleaning time of 5min.

[0049] Step 5: Soak the substrate in an ethanol / acetone mixture for 10 minutes using ultrasonic cleaning and then blow dry. Completely immerse the substrate in sol A for 5 seconds and deposit sol A onto the pre-cleaned substrate at a pull-up speed of 100 mm / min to form the bottom layer film A. Then, completely immerse the substrate in sol B for 5 seconds and deposit sol B onto the bottom layer film A at a pull-up speed of 80 mm / min to form the top layer film B. Repeat this process to deposit 8 layers of SiO2 antireflection film A / B / A / B / A / B / A / B. After pulling out the film, air dry it at room temperature and then dry it in an oven.

[0050] The SiO2 antireflection membrane sample prepared in this comparative example, such as... Figure 6 As shown, the transmittance measured by ultraviolet spectrophotometer exhibits a 'V' shape, with the highest transmittance at the center wavelength of 1053 nm being only 93.89%, far lower than that of Example 1; as Figure 7 As shown, its reflectance at the center wavelength of 1053 nm, measured by an ultraviolet spectrophotometer, is 6.28%, which is much higher than that of Example 1. Therefore, its optical performance is far inferior to that of Example 1.

[0051] The number of devices and processing scale described herein are for the purpose of simplifying the description of the invention. Applications, modifications, and variations of the invention will be readily apparent to those skilled in the art.

[0052] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for preparing a high-performance SiO2 antireflection membrane, characterized in that, include: First, the prepared sol A is dip-coated onto the substrate to form the first film, denoted as film A; then, sol B is dip-coated onto the surface of the first film to form the second film, denoted as film B. The above dip-coating sequence is repeated until an alternating 8-layer high-performance SiO2 antireflection film of A / B / A / B / A / B / A / B is formed. Specifically, the following steps are included: Step 1: Take a certain proportion of tetraethyl orthosilicate, anhydrous ethanol, and ammonia, mix the three solutions and seal them in a reaction vessel, and stir magnetically for a certain time under certain temperature conditions, and then age at room temperature; the volume ratio of tetraethyl orthosilicate, anhydrous ethanol, and ammonia is 1:10:0.5, the stirring temperature is 30 ℃, the stirring time is 12 h, and the aging time is 12 h. Step 2: The sol aged in Step 1 is refluxed and condensed at a certain temperature to remove ammonia, thus obtaining sol A; the reflux condensation temperature is 85 ℃ and the reflux condensation time is 6 h. Step 3: Take a certain proportion of anhydrous ethanol, ammonia, deionized water, hexamethyldisilazane, and tetraethyl orthosilicate, mix the five solutions and seal them in a reaction vessel, and stir magnetically for a certain time under certain temperature conditions, and then age them at room temperature; the volume ratio of anhydrous ethanol, ammonia, deionized water, hexamethyldisilazane, and tetraethyl orthosilicate is 10:0.05:0.2:0.1:1; Step 4: Take out a certain amount of the aged sol from Step 3, add an equal volume of anhydrous ethanol and mix well to obtain sol B; Step 5: Soak the substrate in an ethanol / acetone mixture for ultrasonic cleaning for a certain period of time, then dry it by blowing. Step 6: Perform plasma cleaning on the substrate using a PCE-6 plasma cleaner; Step 7: First, use sol A to deposit a layer A film on the substrate, and then use sol B to deposit a layer B film. Step 8: Repeat step 7 until 8 layers are deposited to obtain 8 high-performance SiO2 antireflection films.

2. The method for preparing the high-performance SiO2 antireflection film as described in claim 1, characterized in that, In step five, the ultrasonic cleaning time is 10 minutes.

3. The method for preparing the high-performance SiO2 antireflection film as described in claim 1, characterized in that, In step six, the plasma cleaning power is 30 W and the cleaning time is 5 min.

4. The method for preparing the high-performance SiO2 antireflection film as described in claim 1, characterized in that, In step seven, the substrate is immersed in the sol for 5 seconds during the coating process, and the lifting speed is 100 mm / min.

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