A method for preparing WO3 nanocone electrochromic film

Abstract

The present invention discloses a method for preparing a WO3 nano-cone array electrochromic film, which is applied to the field of electrochromic materials and devices. In view of the fact that the film structure prepared by the existing magnetron sputtering method is too dense and smooth, resulting in a limited effective contact area with the electrolyte, which in turn limits the further improvement of the performance of the electrochromic device, the present invention proposes a targeted solution; the present invention uses glass coated with indium tin oxide (ITO) on the surface as a substrate, places a silver target and a tungsten target at a DC target position and a radio frequency target position respectively, and uses a co-sputtering coating technology to induce the growth of a WO3 nanoparticle seed layer by doping metallic silver; and uses a reactive sputtering coating technology to grow a WO3 nano-cone array structure on the WO3 nanoparticle seed layer by doping europium. The WO3 nano-cone structure film significantly improves the electrochromic performance compared to the WO3 dense film.

Description

Technical Field

[0001] The present invention belongs to WO 3 The technical field of electrochromic film preparation is particularly related to a WO 3 Preparation method of nanocone electrochromic film. Background Art

[0002] Electrochromism refers to the phenomenon that the optical properties of a material (reflectivity, transmittance, absorptivity, etc.) undergo stable and reversible color changes under the action of a certain electric field or current.

[0003] WO 3 As a widely studied electrochromic (EC) material, it has excellent coloring ability, optical modulation ability and durability. Its electrochromic mechanism is that during the color change process, due to the action of the electric field, cations and electrons are injected into WO 3 W-containing 5+ M x WO 3 (tungsten bronze) structure, the film changes from transparent to blue.

[0004] Magnetron sputtering is a commonly used method for WO because of its advantages such as simple process and suitability for large-scale production. 3 The thin film preparation method, the thin film structure prepared in this way is dense and smooth. Although it has the advantages of strong adhesion to the substrate and good cycle stability, the contact area between the film and the electrolyte is small, cations cannot be effectively injected and extracted, and the electrochromic performance cannot be further improved, such as response time, specific capacitance, ion diffusion coefficient, etc. Therefore, on the basis of not changing the thin film preparation technology, a suitable method is found to prepare WO with a larger specific surface area. 3 Nanostructured films are of great interest. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes a WO that can effectively improve the electrochromic performance. 3 Preparation method of nanocone array electrochromic film.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a WO 3 A method for preparing a nano-cone array electrochromic film comprises:

[0007] S1, cleaning the substrate used for preparing the thin film;

[0008] S2, using silver target and tungsten target as target materials, using magnetron co-sputtering technology, setting corresponding sputtering process parameters, and using silver to induce the growth of WO on the substrate 3 Nanoparticle seed layer;

[0009] S3, using reactive sputtering coating technology, setting the corresponding sputtering process parameters, 3 Europium-doped WO grown on the nanoparticle seed layer 3 Nanocone array structure.

[0010] In the step S1, the substrate is glass with indium tin oxide (ITO) coated on the surface.

[0011] The cleaning process of the substrate in step S1 is: ultrasonically clean the substrate with acetone, ethanol and deionized water for 5 minutes in sequence, blow dry the substrate with high-purity nitrogen, and then use plasma cleaning for 5 minutes under a mixture of argon and oxygen.

[0012] In step S2, the WO 3 The growth process of the nanoparticle seed layer is:

[0013] A1. Fix the substrate on the substrate tray in the vacuum chamber of the magnetron sputtering device, place the silver target and the tungsten target on the DC sputtering target position and the RF sputtering target position in the vacuum chamber of the magnetron sputtering device respectively, adjust the substrate rotation speed to 30-40r / min, and the substrate heating temperature to 120-200℃;

[0014] A2, oxygen and argon are introduced at a rate of 50-70 sccm and 30-50 sccm respectively. After the introduction of oxygen and argon, the working pressure of the vacuum chamber is controlled at 5.0-7.0 Pa, and the DC sputtering power and RF sputtering power are adjusted to 3-7 W and 150-250 W respectively, and the sputtering time is 10-30 min;

[0015] A3. After sputtering, a WO with a diameter of 100-150nm and a height of 100-150nm is formed on the substrate. 3 Nanoparticle seed layer thin film.

[0016] The step S3 of WO 3 The growth process of nanocone array is:

[0017] A1, will grow WO 3 The substrate of the nanoparticle seed layer film is fixed on the substrate tray in the vacuum chamber of the magnetron sputtering device, the tungsten target is placed on the RF sputtering target position in the vacuum chamber of the magnetron sputtering device, the europium sheet is fixed on the tungsten target, the substrate rotation speed is adjusted to 30-40r / min, and the substrate is set to room temperature;

[0018] A2, oxygen and argon are introduced at a rate of 50-70 sccm and 30-50 sccm respectively. After the introduction of oxygen and argon, the working pressure of the vacuum chamber is controlled at 5.0-7.0 Pa, the RF sputtering power is 150-250 W, and the sputtering time is 90-110 min;

[0019] A3. After sputtering, take out the sample from the vacuum chamber and place it on WO 3 WO with a diameter of 200-300nm and a height of 200-400nm is formed on the nanoparticle seed layer. 3 Nanocone array film.

[0020] The beneficial effects of the present invention are as follows: Based on the magnetron sputtering technology, silver-tungsten co-sputtering is used to grow WO 3 Nanoparticle seed layer, on this basis, europium-doped WO was successfully prepared by reactive sputtering. 3 Nanocone array electrochromic film. The preparation method proposed in the present invention can effectively improve WO 3 The surface microstructure of the film greatly improves the WO 3 The contact area between the film and the electrolyte significantly improves the electrochromic properties of the film. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention WO 3 Schematic diagram of the structure of nanocone array electrochromic film;

[0022] Figure 2 This is a real picture of the vacuum chamber of the magnetron sputtering equipment used in the present invention;

[0023] Figure 3 (a) and (b) are WO prepared in Example 1. 3 Surface and cross-sectional scanning electron microscopy (SEM) images of nanoparticle seed layer films;

[0024] Figure 4 (a) and (b) are WO prepared in Example 1. 3 Surface and cross-sectional scanning electron microscopy (SEM) images of nanocone array films;

[0025] Figure 5 is WO prepared in Example 1 3 Nanocone array film and pure WO deposited by magnetron sputtering for 120 min 3 Comparison of visible light transmittance curves of the film in the colored state and the faded state;

[0026] Figure 6 is WO prepared in Example 1 3 Nanocone array film and pure WO deposited by magnetron sputtering for 120 min 3 Comparison of cyclic voltammetry (CV) curves of the films;

[0027] Figure 7 is WO prepared in Example 1 3Nanocone array film and pure WO deposited by magnetron sputtering for 120 min 3 Comparison chart of film response time; DETAILED DESCRIPTION

[0028] To facilitate those skilled in the art to understand the technical content of the present invention, the present invention is further explained below with reference to the accompanying drawings and specific examples.

[0029] like Figure 1 As shown, WO prepared by the present invention 3 A schematic structural diagram of a nanocone array electrochromic film. The preparation method provided by the present invention is described in detail below through specific embodiments to further demonstrate the advantages of the present invention.

[0030] Example 1

[0031] WO of this embodiment 3 The method for preparing a nano-cone array electrochromic film comprises the following steps:

[0032] The technical solution of the present invention is: a packaging method of an electric injection type electrochromic device protected by an insulating material, comprising the following steps:

[0033] S1. Use indium tin oxide (ITO) coated glass as a substrate, use acetone, ethanol, and deionized water to ultrasonically clean for 5 minutes in sequence, blow dry with high-purity nitrogen, and use plasma cleaning for 5 minutes under a mixture of argon and oxygen.

[0034] S2. Fix the substrate on the substrate tray in the magnetron sputtering vacuum chamber, such as Figure 2 As shown in mark 1, the silver target and the tungsten target are placed on the DC sputtering target position and the RF sputtering target position in the vacuum chamber of the magnetron sputtering equipment, respectively. Figure 2 As shown in marks 2 and 3; the substrate rotation speed is adjusted to 30r / min, the substrate heating temperature is 120°C, and the vacuum chamber is evacuated to a vacuum degree of less than 1×10 -3 Pa; oxygen and argon were introduced at a rate of 60 sccm and 40 sccm respectively. After the introduction of oxygen and argon, the working pressure of the vacuum chamber was controlled at 5.5 Pa, and the DC sputtering power and RF sputtering power were adjusted to 5 W and 200 W respectively, and the sputtering time was 20 min. After the sputtering was completed, the sample was taken out of the vacuum chamber, and WO with an average diameter of about 140 nm and an average height of about 170 nm was formed on the substrate. 3 Nanoparticle seed layer thin film.

[0035] S3, will grow WO 3The substrate of the nanoparticle seed layer film is fixed on the substrate tray in the magnetron sputtering vacuum chamber. The tungsten target is placed on the RF sputtering target position in the vacuum chamber of the magnetron sputtering equipment. The europium sheet is fixed on the tungsten target. The substrate rotation speed is adjusted to 30r / min. The substrate is set to room temperature. The vacuum chamber is evacuated to a vacuum degree of less than 6×10 -4 Pa; oxygen and argon were introduced at a rate of 60 sccm and 40 sccm respectively. After the introduction of oxygen and argon, the working pressure of the vacuum chamber was controlled at 5.5 Pa, the RF sputtering power was 200 W, and the sputtering time was 120 min. After the sputtering was completed, the sample was taken out of the vacuum chamber and placed on WO 3 WO with an average diameter of about 200 nm and an average height of about 300 nm is formed on the nanoparticles. 3 Nanocone array film.

[0036] Figure 3 (a) and (b) are WO prepared in this example. 3 Scanning electron microscope (SEM) images of the surface and cross section of the nanoparticle seed layer film. This figure shows that this embodiment successfully grows WO with uniform size on the ITO glass substrate. 3 Nanoparticle seed layer.

[0037] Figure 4 (a) and (b) are WO prepared in this example. 3 Scanning electron microscope (SEM) images of the surface and cross section of the nanocone array film. This figure shows that this embodiment successfully 3 Vertical WO growth on the nanoparticle seed layer 3 Nanocone arrays.

[0038] Figure 5 is the WO prepared in this example 3 Nanocone array film and pure WO deposited by magnetron sputtering for 120 min 3 Comparison of visible light transmittance curves of the film in the colored state and the faded state. 3 Nanocone array film compared with pure WO 3 The film has improved light modulation in the visible light range.

[0039] Figure 6 is the WO prepared in this example 3 Nanocone array film and pure WO deposited by magnetron sputtering for 120 min 3 Comparison of cyclic voltammetry (CV) curves of films. This figure shows that the WO prepared in this example 3 Nanocone array film compared with pure WO 3 The charges and ions injected into the film increased significantly.

[0040] Figure 7 is the WO prepared in this example 3 Nanocone array film and pure WO deposited by magnetron sputtering for 120 min 3 The film response time comparison chart shows that the WO prepared in this example 3 Nanocone array film compared with pure WO 3 Film fading and staining time is significantly reduced.

[0041] Example 2

[0042] The method for preparing the WO3 nano-cone array electrochromic film of this embodiment comprises the following steps:

[0043] The technical solution of the present invention is: a packaging method of an electric injection type electrochromic device protected by an insulating material, comprising the following steps:

[0044] S1. Use indium tin oxide (ITO) coated glass as a substrate, use acetone, ethanol, and deionized water to ultrasonically clean for 5 minutes in sequence, blow dry with high-purity nitrogen, and use plasma cleaning for 5 minutes under a mixture of argon and oxygen.

[0045] S2. Fix the substrate on the substrate tray in the magnetron sputtering vacuum chamber, such as Figure 2 As shown in mark 1, the silver target and the tungsten target are placed on the DC sputtering target position and the RF sputtering target position in the vacuum chamber of the magnetron sputtering equipment, respectively. Figure 2 As shown in marks 2 and 3; the substrate rotation speed is adjusted to 30r / min, the substrate heating temperature is 80°C, and the vacuum chamber is evacuated to a vacuum degree of less than 3×10 -3 Pa; oxygen and argon were introduced at a rate of 60 sccm and 40 sccm respectively. After the introduction of oxygen and argon, the working pressure of the vacuum chamber was controlled at 4.8 Pa. The DC sputtering power and RF sputtering power were adjusted to 5 W and 200 W respectively, and the sputtering time was 20 min. After the sputtering was completed, the sample was taken out of the vacuum chamber, and WO with an average diameter of about 130 nm and an average height of about 150 nm was formed on the substrate. 3 Nanoparticle seed layer thin film.

[0046] S3, will grow WO 3 The substrate of the nanoparticle seed layer film is fixed on the substrate tray in the magnetron sputtering vacuum chamber. The tungsten target is placed on the RF sputtering target position in the vacuum chamber of the magnetron sputtering equipment. The europium sheet is fixed on the tungsten target. The substrate rotation speed is adjusted to 30r / min. The substrate is set to room temperature. The vacuum chamber is evacuated to a vacuum degree of less than 6×10 -4Pa; oxygen and argon were introduced at a rate of 60 sccm and 40 sccm respectively. After the introduction of oxygen and argon, the working pressure of the vacuum chamber was controlled at 4.8 Pa, the RF sputtering power was 200 W, and the sputtering time was 120 min. After the sputtering was completed, the sample was taken out of the vacuum chamber and placed on WO 3 WO with an average diameter of about 200 nm and an average height of about 280 nm is formed on the nanoparticles. 3 Nanocone array film.

[0047] After testing, the above preparation method can greatly improve WO 3 The specific surface area of ​​the film increases the WO 3 Thin film electrochromic properties.

[0048] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the scope of protection of the present invention is not limited to such specific statements and embodiments. For those skilled in the art, the present invention may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for preparing a WO3 nanocone array electrochromic film, characterized in that: include: S1, cleaning the substrate used for preparing the thin film; S2, using silver target and tungsten target as target materials, using magnetron co-sputtering technology, setting corresponding sputtering process parameters, and using silver to induce the growth of WO3 nanoparticle seed layer on the substrate; S3. Using reactive sputtering coating technology, setting corresponding sputtering process parameters, and growing a europium-doped WO3 nano-cone array structure on the WO3 nano-particle seed layer.

2. The method for preparing a WO3 nano-cone array electrochromic film according to claim 1, characterized in that: The substrate described in step S1 is glass with indium tin oxide (ITO) coated on the surface.

3. The method for preparing a WO3 nano-cone array electrochromic film according to claim 1, characterized in that: The cleaning process of the substrate in step S1 is: ultrasonically clean the substrate with acetone, ethanol and deionized water for 5 minutes in sequence, blow dry the substrate with high-purity nitrogen, and then use plasma cleaning for 5 minutes under a mixture of argon and oxygen.

4. The method for preparing a WO3 nano-cone array electrochromic film according to claim 1, characterized in that: The WO3 nanoparticle growth process in step S2 is as follows: A1. Fix the substrate on the substrate tray in the vacuum chamber of the magnetron sputtering device, place the silver target and the tungsten target on the DC sputtering target position and the RF sputtering target position in the vacuum chamber of the magnetron sputtering device respectively, adjust the substrate rotation speed to 30-40r / min, and the substrate heating temperature to 120-200℃; A2, oxygen and argon are introduced at a rate of 50-70 sccm and 30-50 sccm respectively. After the introduction of oxygen and argon, the working pressure of the vacuum chamber is controlled at 5.0-7.0 Pa, and the DC sputtering power and RF sputtering power are adjusted to 3-7 W and 150-250 W respectively, and the sputtering time is 10-30 min; A3. After the sputtering is completed, a WO3 nanoparticle seed layer film with a diameter of 100-150nm and a height of 100-150nm is formed on the substrate.

5. The method for preparing a WO3 nano-cone array electrochromic film according to claim 4, characterized in that: The purity of the silver target in step A1 is 99.99%, and the purity of the tungsten target is 99.99%.

6. The method for preparing a WO3 nanocone electrochromic film according to claim 1, characterized in that: The growth process of the WO3 nano-cone array in step S3 is as follows: A1. Fix the substrate with the WO3 nanoparticle seed layer film grown on the substrate tray in the vacuum chamber of the magnetron sputtering device, place the tungsten target on the RF sputtering target position in the vacuum chamber of the magnetron sputtering device, fix the europium sheet on the tungsten target, adjust the substrate rotation speed to 30-40r / min, and set the substrate to room temperature; A2, oxygen and argon are introduced at a rate of 50-70 sccm and 30-50 sccm respectively. After the introduction of oxygen and argon, the working pressure of the vacuum chamber is controlled at 5.0-7.0 Pa, the RF sputtering power is 150-250 W, and the sputtering time is 90-110 min; A3. After the sputtering is completed, the sample is taken out from the vacuum chamber, and a WO3 nano-cone array film with a diameter of 200-300 nm and a height of 200-400 μm is formed on the WO3 nano-particle seed layer.

7. The method for preparing a WO3 nano-cone array electrochromic film according to claim 6, characterized in that: Step A1: The purity of the tungsten target is 99.99%, the purity of the europium sheet is 99.99%, and the area is 0.2-0.6 cm 2 .

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