Preparation method of transparent copper-tungsten oxide film

Abstract

The invention provides a preparation method of a transparent copper-tungsten oxide film, which comprises the following steps: cleaning and blow-drying a glass substrate, placing the treated glass substrate on a substrate table of a magnetron sputtering coating machine, vacuumizing a vacuum chamber, and after the vacuum degree reaches a target value, carrying out vacuum coating on the glass substrate to obtain the transparent copper-tungsten oxide film. Introducing high-purity argon into the vacuum chamber; when the pressure of argon in the vacuum chamber reaches 0.7-0.8 Pa, sputtering a Cu target and a W target at the same time to obtain oxide films with different thicknesses; when the thickness of the oxide thin film is 30-100 nm, the obtained oxide thin film is the transparent copper-tungsten oxide thin film; and when the thickness of the oxide film is greater than 100nm, soaking the obtained oxide film in deionized water in a room temperature environment to obtain the transparent copper-tungsten oxide film. The transparent copper-tungsten oxide thin films with different thicknesses can be prepared by adopting a sputtering method or adopting the sputtering method and a simple and environment-friendly room-temperature soaking method, and the method is convenient to operate, low in cost, green and environment-friendly.

Description

Technical Field

[0001] The invention relates to the technical field of oxide thin films, in particular to a method for preparing a transparent copper-tungsten oxide thin film. Background Art

[0002] Transparent oxide films have been widely used in catalysis, sensing and other fields due to their unique optical properties. For example, transparent ITO and AZO films can be used as transparent electrodes in displays, touch screens, solar cells and other devices. Transparent oxide films can effectively reflect blue and purple light, which can promote the growth of crops in the agricultural field; transparent oxide films deposited on glass substrates can be used as optical filters, and transparent oxide glass optical elements can be used to prepare achromatic lenses; transparent oxide films in low-emissivity glass can block ultraviolet rays and reduce radiation, and transparent oxide films can also be used for decoration and shielding in daily life.

[0003] At present, there are a large number of reports on the preparation of oxide thin films, such as electron beam evaporation, magnetron sputtering, vapor deposition, plasma-assisted molecular beam epitaxy, electrochemical deposition, spray thermal decomposition, etc. Among the above preparation methods, the vapor deposition method has high film quality and can achieve high-speed, large-area, uniform, and multi-piece growth at one time, but the raw materials are chemically unstable, toxic and expensive, and the tail gas needs special equipment to handle; although the molecular beam epitaxy method can accurately control the deposition parameters and realize dynamic and real-time monitoring of the epitaxial growth mode of the thin film, the growth of the film is too slow and difficult to use in production. It is difficult to grow multi-component thin films and the growth temperature cannot be too high. Among them, the magnetron sputtering process is an indispensable process flow in semiconductor chips, optical glass and new display devices due to its advantages such as simple equipment, easy control, large coating area and strong adhesion. The use of magnetron sputtering technology to prepare high-quality thin films has always been one of the focuses of related process development. At present, magnetron sputtering technology is mostly used to prepare metal oxide thin films by reactive sputtering, with a metal target as the cathode, argon and oxygen introduced for reaction, and the desired thin film is generated on the substrate. Although magnetron sputtering can achieve thin film growth under a controlled atmosphere, it cannot effectively guarantee the transparency of the oxide thin film, especially when the film thickness is thick, which will increase its light absorption, resulting in a decrease in light transmittance and lower transparency of the oxide thin film. Summary of the invention

[0004] In order to solve the deficiencies in the prior art, the present invention provides a method for preparing a transparent copper tungsten oxide film. Transparent copper tungsten oxide films of different thicknesses can be prepared by adopting a "sputtering method" or a "sputtering method + a simple and environmentally friendly immersion method at room temperature". The method is easy to operate, low in cost, and environmentally friendly.

[0005] In order to achieve the above object, the specific scheme adopted by the present invention is: A method for preparing a transparent copper-tungsten oxide film mainly comprises the following steps: S1, washing the glass substrate with anhydrous ethanol and deionized water in turn and then drying it; S2, placing the treated glass substrate on the substrate table of the magnetron sputtering coating machine, evacuating the vacuum chamber, and after the vacuum degree reaches the target value, introducing high-purity argon gas into the vacuum chamber; S3. When the argon pressure in the vacuum chamber reaches 0.7-0.8 Pa, the Cu target and the W target are sputtered simultaneously to obtain oxide films of different thicknesses; When the thickness of the oxide film is between 30 and 100 nm, the obtained oxide film is a transparent copper-tungsten oxide film; When the thickness of the oxide film is greater than 100 nm, the obtained oxide film is immersed in deionized water at room temperature to obtain a transparent copper-tungsten oxide film.

[0006] Furthermore, in step S2, the atomic percentage of tungsten in the oxide film is 25-50 at%.

[0007] Furthermore, in step S2, when the thickness of the oxide film is between 30 and 100 nm, the vacuum target value is 5*10 -3 ~9*10 -3 Pa; When the thickness of the oxide film is greater than 100nm, the vacuum target value is 9*10 -3 ~6*10 -4 Pa.

[0008] Further, in step S3, the Cu target and the W target are sputtered simultaneously for 30 to 120 seconds to obtain an oxide film with a thickness of 30 to 100 nm; The Cu target and the W target were sputtered simultaneously for 120 to 360 seconds to obtain an oxide film with a thickness greater than 100 nm.

[0009] Furthermore, in step S3, the soaking time is 1 to 20 hours.

[0010] Beneficial effects: (1) In the sputtering process of the present invention, there is no need to introduce oxygen, heat the substrate stage, introduce oxygen into the coating chamber, or perform post-heat treatment on the sample. A transparent copper tungsten oxide film can be prepared by a "sputtering method" or a "sputtering method + a simple and environmentally friendly immersion method at room temperature". Unlike the previous method of preparing transparent oxide films, which usually requires preheating of the substrate or preparation first and then high-temperature annealing, the preparation method proposed by the present invention does not require heating, is easy to operate, low in cost, and environmentally friendly.

[0011] (2) The present invention adds an appropriate amount of W element to the Cu film, so that some gaps and vacancies exist on the surface and inside of the composite film, which is convenient for the adsorption of O molecules. During the deposition process, the vacuum degree is controlled so that the O atoms remaining in the vacuum chamber enter the film through the gaps and vacancies, thereby partially converting the zero-valent Cu in the alloy film into 0 , W 0 Oxidized to Cu + , W 6+ , a thin transparent copper tungsten oxide film can be obtained.

[0012] (3) The present invention takes the deposited sample out of the vacuum chamber and immerses it in deionized water for a certain period of time, allowing the oxygen molecules in the water to diffuse into the film and react with Cu and W to produce oxides. Even if the film is thick, a transparent copper-tungsten oxide film can be prepared. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is the macroscopic morphology of the sample prepared in Example 1.

[0014] Figure 2 This is a scan of the surface morphology of the sample prepared in Example 1.

[0015] Figure 3 This is the valence state XPS diagram of the sample prepared in Example 1.

[0016] Figure 4 This is the macroscopic morphology of the sample prepared in Example 2.

[0017] Figure 5 This is the macroscopic morphology of the oxide film in Example 3.

[0018] Figure 6 This is the macroscopic morphology of the oxide film in Example 3 after immersion.

[0019] Figure 7 This is the valence state XPS diagram of the sample prepared in Example 3.

[0020] Figure 8 This is the macroscopic morphology of the oxide film in Example 4.

[0021] Fig. 9 This is the macroscopic morphology of the oxide film in Example 4 after immersion.

[0022] Fig.10 This is the macroscopic morphology of the oxide film in Example 5.

[0023] Fig.11 This is the macroscopic morphology of the oxide film in Example 5 after immersion.

[0024] Fig.12This is the macroscopic morphology of the sample prepared in Comparative Example 1. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] Example 1 A method for preparing a transparent copper-tungsten oxide film mainly comprises the following steps: S1. Glass substrate cleaning The glass substrate was placed in a beaker filled with anhydrous ethanol, and the beaker was placed in an ultrasonic cleaning machine for ultrasonic cleaning for 5 minutes, and then the cleaned glass was placed in a beaker filled with deionized water for ultrasonic cleaning for 10 minutes, and the cleaned glass substrate was blown dry with nitrogen, and then the substrate was fixed to the substrate stage of the magnetron sputtering coating machine; S2. Target preparation and vacuum control The coating was carried out using a JCP-350 DC magnetron sputtering coating machine. The Cu target and W target were placed at the target position of the coating machine. After the target material and the glass substrate were placed, the vacuum chamber of the coating machine was closed and the vacuum chamber was evacuated to a vacuum degree of 7*10 -3 Pa; S3. Deposition and preparation of transparent copper tungsten oxide thin film High-purity argon gas was introduced into the vacuum chamber to make the gas pressure in the vacuum chamber reach 0.7 Pa, and then the power of the Cu target and the W target were turned on at the same time to start sputtering, and a composite film was deposited on the glass substrate for 60 s to prepare a Cu-32W at% oxide film with a thickness of 92 nm, i.e. a transparent copper tungsten oxide film was obtained.

[0027] The macroscopic morphology of the sample prepared in this example is as follows Figure 1 As shown by Figure 1 It can be seen that the film layer is transparent light yellow. Figure 2 The surface morphology scanning diagram of the sample prepared in this embodiment is shown in FIG. Figure 2 It can be seen that the surface of the film is flat and smooth. Figure 3 The valence state XPS diagram of the sample prepared in this example is shown. Figure 3 It can be seen that there is Cu in the film + , W 6+ , indicating that this example indeed prepared a transparent copper tungsten oxide film.

[0028] Example 2 The difference between Example 2 and Example 1 is that in step S3, the deposition time is 30s and the film thickness is 50nm. The macroscopic morphology of the sample prepared in this example is as follows: Figure 4 As shown by Figure 4 It can be seen that the film layer is transparent light yellow.

[0029] Example 3 A method for preparing a transparent copper-tungsten oxide film mainly comprises the following steps: S1. Glass substrate cleaning The glass substrate was placed in a beaker filled with anhydrous ethanol, and the beaker was placed in an ultrasonic cleaning machine for ultrasonic cleaning for 15 minutes. The cleaned glass substrate was then placed in a beaker filled with deionized water for ultrasonic cleaning for 8 minutes. The cleaned glass substrate was blown dry with nitrogen, and then the substrate was fixed to the substrate stage of the magnetron sputtering coating machine. S2. Target preparation and vacuum control The coating is carried out using a JCP-350 DC magnetron sputtering coating machine. The Cu target and W target are placed at the target position of the coating machine. After the target material and the glass substrate are placed, the vacuum chamber of the coating machine is closed and the vacuum chamber is evacuated to a vacuum degree of 9*10 -3 Pa; S3. Deposition and preparation of oxide thin film High-purity argon gas was introduced into the vacuum chamber to make the pressure in the vacuum chamber reach 0.8 Pa, and then the power of the Cu target and the W target were turned on at the same time to start sputtering, and the composite film was deposited on the glass substrate for 120 seconds to prepare a Cu-30 W at % oxide film with a film thickness of 220 nm. The macroscopic morphology of the oxide film is shown in FIG. Figure 5 As shown by Figure 5 It can be seen that the film is opaque; S4. Preparation of transparent copper tungsten oxide film by immersion Take out the prepared oxide film sample and soak it in deionized water at room temperature for 1 hour to prepare a transparent copper tungsten oxide film. The macroscopic morphology of the transparent copper tungsten oxide film is shown in Figure 2. Figure 6 As shown by Figure 6 It can be seen that the film layer is transparent light yellow. Figure 7 The valence state XPS diagram of the sample prepared in this example is shown. Figure 7 It can be seen that there is Cu in the film + , W 6 + , indicating that this example indeed prepared a transparent copper tungsten oxide film.

[0030] Example 4 The difference between Example 4 and Example 3 is that: (1) in step S2, the vacuum degree is set to 9*10 -4Pa; (2) In step S3, the deposition time is 240s, and a Cu-39 W at % oxide film is prepared with a film thickness of 438nm; the macroscopic morphology of the oxide film is as follows Figure 8 As shown by Figure 8 It can be seen that the film is opaque; (3) In step S4, after immersion for 10 hours, a transparent copper tungsten oxide film is obtained. The macroscopic morphology of the transparent copper tungsten oxide film is as follows: Fig. 9 As shown by Fig. 9 It can be seen that the film layer is transparent.

[0031] Example 5 The difference between Example 5 and Example 3 is that: (1) in step S2, the vacuum degree is set to 6*10 -4 Pa; (2) In step S3, the deposition time is 360s, and a Cu-50W at% oxide film is prepared with a film thickness of 600nm; the macroscopic morphology of the oxide film is as follows Fig.10 As shown by Fig.10 It can be seen that the film is opaque; (3) In step S4, after immersion for 20 hours, a transparent copper tungsten oxide film is obtained. The macroscopic morphology of the transparent copper tungsten oxide film is as follows: Fig.11 As shown by Fig.11 It can be seen that the film layer is transparent yellow.

[0032] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that: (1) in step S2, the vacuum degree is set to 6*10 -4 Pa, the macroscopic morphology of the obtained oxide film is as follows Fig.12 As shown by Fig.12 It can be seen that the film is opaque.

[0033] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any equivalent changes or modifications made according to the essence of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a transparent copper-tungsten oxide thin film, characterized in that: The main steps are as follows: S1, washing the glass substrate with anhydrous ethanol and deionized water in turn and then drying it; S2, placing the treated glass substrate on the substrate table of the magnetron sputtering coating machine, evacuating the vacuum chamber, and after the vacuum degree reaches the target value, introducing high-purity argon gas into the vacuum chamber; S3. When the argon pressure in the vacuum chamber reaches 0.7-0.8 Pa, the Cu target and the W target are sputtered simultaneously to obtain oxide films of different thicknesses; When the thickness of the oxide film is between 30 and 100 nm, the obtained oxide film is a transparent copper-tungsten oxide film; When the thickness of the oxide film is greater than 100 nm, the obtained oxide film is immersed in deionized water at room temperature to obtain a transparent copper-tungsten oxide film.

2. The method for preparing a transparent copper-tungsten oxide thin film according to claim 1, characterized in that: In step S2, the atomic percentage of tungsten in the oxide film is 25-50 at%.

3. The method for preparing a transparent copper-tungsten oxide thin film according to claim 1, characterized in that: In step S2, when the thickness of the oxide film is between 30 and 100 nm, the vacuum target value is 5*10 -3 ~9*10 -3 Pa; When the thickness of the oxide film is greater than 100nm, the vacuum target value is 9*10 -3 ~6*10 -4 Pa.

4. The method for preparing a transparent copper-tungsten oxide thin film according to claim 1, characterized in that: In step S3, the Cu target and the W target are sputtered simultaneously for 30 to 120 seconds to obtain an oxide film with a thickness of 30 to 100 nm; The Cu target and the W target were sputtered simultaneously for 120 to 360 seconds to obtain an oxide film with a thickness greater than 100 nm.

5. The method for preparing a transparent copper-tungsten oxide thin film according to claim 1, characterized in that: In step S3, the soaking time is 1 to 20 hours.

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