Antimony-doped tin dioxide transparent conductive thin film and preparation method thereof

Abstract

The application discloses a kind of antimony-doped tin dioxide transparent conductive film and preparation method thereof.The preparation method of the film includes the following steps: (1) using vacuum evaporation method to form tin / antimony / tin layered sandwich structure metal film on the surface of substrate;(2) the metal film prepared in step (1) is used as working electrode, and platinum electrode is used as counter electrode for electrolysis;(3) the metal film after electrolysis is taken out for cleaning, and then annealing treatment is carried out, to obtain the antimony-doped tin dioxide transparent conductive film.The application obtains tin dioxide film by vacuum evaporation of tin and antimony metal, and obtains transparent conductive tin dioxide film after high-temperature annealing.The sheet resistance of the film can reach 198Ω / □, and the light transmittance can reach more than 70% after the film is doped with antimony.The application has the advantages of good universality, low equipment requirement, simple preparation and good repeatability, and has good popularization value.

Description

Technical Field

[0001] This invention relates to the field of transparent conductive thin film technology, specifically to an antimony-doped tin dioxide transparent conductive thin film and its preparation method. Background Technology

[0002] Transparent conductive films are in high demand as important electrode materials in the semiconductor industry. Highly conductive and highly transparent conductive films, with their excellent electrical properties, optical performance, and high stability, are widely used in electronic and optical devices, such as touchscreens, detectors, liquid crystal displays, and solar cells (Defect and Diffusion Forum, 2022, 417, 243).

[0003] Among all the studied semiconductor metal oxide transparent conductive thin film (TCO) materials, Sn-doped In₂O₃ (ITO) exhibits excellent transmittance and conductivity, dominating applications in optoelectronic devices, particularly high-end screen displays. However, the scarcity and dispersion of indium in the Earth's crust limits its production and increases its price, making it difficult to meet the rapidly growing market demand. Tin dioxide is a broadband semiconductor oxide material with good transparency, conductivity, and physicochemical stability, boasting a band gap as high as 3.8 eV. It possesses unique optical, electrical, and catalytic properties and is widely used in adsorption catalysis, gas sensors, semiconductor conductive glasses, and solar cells. However, tin dioxide also suffers from bulk and surface defects that trap charge carriers and impair its electronic properties. Furthermore, tin dioxide-based transparent conductive films exhibit spontaneous aggregation effects, forming pinholes or island-like structures within the film that hinder electron migration. To address these issues, a crucial strategy is ion doping to alter the band structure and trapped states of tin dioxide. Alkali metal ions such as Li₂O₃... + K + and Mg 2+ It is expected to improve the conductivity and stability of the electron transport layer of tin dioxide, and the superior conductivity of alkali ions can reduce series resistance, thereby increasing open-circuit voltage (Nanoscale Research Letters, 2017, 12, 238). Other ions, such as Cd... 3+ Sb 3+ and Y 3+ The aim is to create donor centers within the thin film to accelerate charge migration and thus improve the film's conductivity (Advanced Energy Materials, 2018, 8, 20).

[0004] Although there has been much research on tin dioxide-based transparent conductive films, there are still problems such as high equipment requirements and complex preparation methods. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, this invention provides an antimony-doped tin dioxide transparent conductive film and its preparation method. This invention takes a novel approach, preparing an antimony-doped tin dioxide transparent conductive film through vacuum evaporation and anodic oxidation. This invention features low equipment requirements, a simple preparation method, controllable cost, and environmental friendliness, and has good potential for widespread application. To achieve the above objectives, the technical solution adopted by this invention is as follows:

[0006] The first aspect of this invention provides a method for preparing an antimony-doped tin dioxide transparent conductive film, comprising the following steps:

[0007] (1) A metal thin film with a tin / antimony / tin layer sandwich structure is formed on the substrate surface using vacuum evaporation;

[0008] (2) Electrolysis is performed using the metal thin film prepared in step (1) as the working electrode and the platinum electrode as the counter electrode.

[0009] (3) Take out the electrolytic metal film, clean it, and then perform annealing to obtain the antimony-doped tin dioxide transparent conductive film.

[0010] In some embodiments of the present invention, the substrate is a glass substrate; the glass substrate is cleaned and placed on a vacuum evaporation machine substrate, and metallic tin, metallic antimony, and metallic tin are placed sequentially on a tungsten boat. After being heated by electricity, a metal thin film with a tin / antimony / tin layered sandwich structure is formed.

[0011] Preferably, in step (1), the amount of tin in the two tin layers of the metal film is the same.

[0012] Preferably, in step (1), the ratio of the total amount of tin in the two tin layers to the amount of antimony in the antimony layer is (5-20):1.

[0013] Preferably, in step (2), the electrolyte used for electrolysis is prepared by deionized water and dimethyl sulfoxide in a volume ratio of 1:(0.5-1.5), and (0.15-0.25) mol / L citric acid monohydrate is added to the solution; in some preferred embodiments of the present invention, the electrolyte used for electrolysis is prepared by deionized water and dimethyl sulfoxide in a volume ratio of 1:1, and (0.15-0.25) mol / L citric acid monohydrate is added to the solution.

[0014] Preferably, in step (2), the electrolysis voltage is 2-6V; more preferably, the electrolysis voltage is 3-5V.

[0015] Preferably, in step (2), the electrolytic voltage is applied for 1-6 minutes; more preferably, the electrolytic voltage is applied for 2-5 minutes.

[0016] Preferably, in step (3), the electrolyzed metal film is taken out, rinsed with anhydrous ethanol, and then naturally dried before annealing.

[0017] Preferably, in step (3), the annealing temperature is 450-550°C; more preferably, the annealing temperature is 480-520°C; in some preferred embodiments of the present invention, the annealing temperature is 500°C.

[0018] Preferably, in step (3), the annealing time is 2.5-3.5h; more preferably, the annealing time is 2.8-3.2h; in some preferred embodiments of the present invention, the annealing time is 3h.

[0019] A second aspect of the present invention provides an antimony-doped tin dioxide transparent conductive film, which is prepared by the aforementioned preparation method.

[0020] Preferably, the visible light transmittance of the antimony-doped tin dioxide transparent conductive film is ≥65%.

[0021] Preferably, the sheet resistance of the antimony-doped tin dioxide transparent conductive film is ≥180Ω / □.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] This invention involves vacuum evaporation of tin and antimony metals, followed by anodic oxidation to obtain a tin dioxide thin film, and then high-temperature annealing to obtain a transparent conductive tin dioxide thin film. After antimony doping, the transparent conductive tin dioxide thin film exhibits a sheet resistance of 198 Ω / □ and a light transmittance exceeding 70%. This invention has advantages such as good versatility, low equipment requirements, simple preparation, and good reproducibility, making it highly valuable for widespread application. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of an electrochemical workstation.

[0025] Figure 2 This is a schematic diagram of a metal thin film after vacuum evaporation.

[0026] Figure 3 The Mott-Schottky pattern of the antimony-doped tin dioxide transparent conductive film of Example 1 is shown.

[0027] Appendix Figure 1 mark:

[0028] 1-Power supply, 2-Working electrode, 3-Counter electrode, 4-Electrolyte. Detailed Implementation

[0029] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.

[0031] Example 1

[0032] This embodiment provides a method for preparing an antimony-doped tin dioxide transparent conductive film, which specifically includes the following steps:

[0033] (1) Clean the ultra-white glass substrate with a cleaning agent and boil it in deionized water. Then, ultrasonically clean it for ten minutes each with deionized water, anhydrous ethanol, and deionized water. Remove the glass and dry it in a dryer for later use.

[0034] (2) Weigh 0.8g of tin and divide it into two portions. Weigh 0.08g of antimony for later use.

[0035] (3) Place the ultra-white glass substrate on the base of the vacuum evaporation machine and put 0.4g of metallic tin in the tungsten boat.

[0036] (4) After evacuating the glass cover of the vacuum evaporation machine, gradually increase the current passing through the tungsten boat until the tin metal dissolves and evaporates at a uniform rate, so that the tin vapor evaporates onto the glass substrate to form a tin metal film.

[0037] (5) Place 0.08g of metallic antimony in a tungsten boat and repeat step (4) to allow antimony vapor to evaporate onto the glass substrate.

[0038] (6) Place 0.4g of metallic tin in a tungsten boat and repeat step (4) to allow tin vapor to evaporate onto the glass substrate.

[0039] (7) Remove the metal thin film and use it as the working electrode, and use the platinum metal sheet as the counter electrode, such as Figure 1 As shown, the operating power supply was set to 5V, and the bias voltage was applied for 4 minutes. The electrolyte consisted of 25mL deionized water and 25mL dimethyl sulfoxide, with a 0.15mol / L citric acid monohydrate solution added.

[0040] (8) The obtained intermediate film was rinsed with anhydrous ethanol, air-dried naturally, and then placed in a heating furnace and annealed at 500 degrees Celsius for 3 hours to finally obtain an antimony-doped tin dioxide transparent conductive film.

[0041] Testing showed that the visible light transmittance of the antimony-doped tin dioxide transparent conductive film was greater than 70%, and its carrier concentration was n = 4.73 × 10⁻⁶. 20 cm -3 Its sheet resistance is 198Ω / □ and its conductivity is 10.929S / cm.

[0042] Example 2

[0043] This embodiment provides a method for preparing an antimony-doped tin dioxide transparent conductive film, which specifically includes the following steps:

[0044] (1) Repeat step (1) in Example 1.

[0045] (2) Weigh 0.8g of tin and divide it into two portions. Weigh 0.04g of antimony for later use.

[0046] (3) Except that the amount of antimony metal used is 0.04g, repeat steps (3-6) in Example 1.

[0047] (4) Remove the metal thin film and use it as the working electrode, and use the platinum metal sheet as the counter electrode, such as Figure 1 As shown, the operating power supply was set to 5V, and the bias voltage was applied for 4 minutes. The electrolyte consisted of 25mL deionized water and 25mL dimethyl sulfoxide, with a 0.15mol / L citric acid monohydrate solution added.

[0048] (5) The obtained intermediate film was rinsed with anhydrous ethanol, air-dried naturally, and then placed in a heating furnace and annealed at 500 degrees Celsius for 3 hours to finally obtain an antimony-doped tin dioxide transparent conductive film.

[0049] Tests showed that the antimony-doped tin dioxide transparent conductive film has a visible light transmittance of over 70%, a sheet resistance of 315 Ω / □, and a conductivity of 6.949 S / cm.

[0050] Example 3

[0051] This embodiment provides a method for preparing an antimony-doped tin dioxide transparent conductive film, which specifically includes the following steps:

[0052] (1) Repeat step (1) in Example 1.

[0053] (2) Weigh 0.8g of tin and divide it into two portions. Weigh 0.16g of antimony for later use.

[0054] (3) Except that the amount of antimony metal used is 0.16g, repeat steps (3-6) in Example 1.

[0055] (4) Remove the metal thin film and use it as the working electrode, and use the platinum metal sheet as the counter electrode, such as Figure 1 As shown, the operating power supply was set to 5V, and the bias voltage was applied for 4 minutes. The electrolyte consisted of 25mL deionized water and 25mL dimethyl sulfoxide, with a 0.15mol / L citric acid monohydrate solution added.

[0056] (5) The obtained intermediate film was rinsed with anhydrous ethanol, air-dried naturally, and then placed in a heating furnace and annealed at 500 degrees Celsius for 3 hours to finally obtain an antimony-doped tin dioxide transparent conductive film.

[0057] Tests showed that the antimony-doped tin dioxide transparent conductive film has a visible light transmittance of over 70%, a sheet resistance of 425 Ω / □, and a conductivity of 4.963 S / cm.

[0058] Example 4

[0059] This embodiment provides a method for preparing an antimony-doped tin dioxide transparent conductive film, which specifically includes the following steps:

[0060] (1) Repeat step (1) in Example 1.

[0061] (2) Weigh 0.4g of tin and divide it into two portions. Weigh 0.04g of antimony for later use.

[0062] (3) Except that the amount of tin is 0.4g and the amount of antimony is 0.04g, repeat steps (3-6) in Example 1.

[0063] (4) Remove the metal thin film and use it as the working electrode, and use the platinum metal sheet as the counter electrode, such as Figure 1 As shown, the operating power supply was set to 5V, and the bias voltage was applied for 4 minutes. The electrolyte consisted of 25mL deionized water and 25mL dimethyl sulfoxide, with a 0.15mol / L citric acid monohydrate solution added.

[0064] (5) The obtained intermediate film was rinsed with anhydrous ethanol, air-dried naturally, and then placed in a heating furnace and annealed at 500 degrees Celsius for 3 hours to finally obtain an antimony-doped tin dioxide transparent conductive film.

[0065] Tests showed that the visible light transmittance of the antimony-doped tin dioxide transparent conductive film was greater than 76%, and the sheet resistance was 864 Ω / □.

[0066] Example 5

[0067] This embodiment provides a method for preparing an antimony-doped tin dioxide transparent conductive film, which specifically includes the following steps:

[0068] (1) Repeat step (1) in Example 1.

[0069] (2) Weigh 1.2g of tin and divide it into two portions. Weigh 0.12g of antimony for later use.

[0070] (3) Except that the amount of tin is 1.2g and the amount of antimony is 0.12g, repeat steps (3-6) in Example 1.

[0071] (4) Remove the metal thin film and use it as the working electrode, and use the platinum metal sheet as the counter electrode, such as Figure 1 As shown, the operating power supply was set to 5V, and the bias voltage was applied for 4 minutes. The electrolyte consisted of 25mL deionized water and 25mL dimethyl sulfoxide, with a 0.15mol / L citric acid monohydrate solution added.

[0072] (5) The obtained intermediate film was rinsed with anhydrous ethanol, air-dried naturally, and then placed in a heating furnace and annealed at 500 degrees Celsius for 3 hours to finally obtain an antimony-doped tin dioxide transparent conductive film.

[0073] Tests showed that the visible light transmittance of the antimony-doped tin dioxide transparent conductive film was greater than 65%, and the sheet resistance was 432 Ω / □.

[0074] Based on Example 1, the ratio of tin to antimony and the film thickness were adjusted to obtain the sheet resistance and conductivity data shown in Table 1 below:

[0075] Table 1

[0076] Sn:Sb Thin film thickness (μm) Shear resistance (Ω / □) Electrical conductivity σ (S / cm) 20:1 4.568 315 6.949 10:1 4.623 198 10.929 5:1 4.742 425 4.963

[0077] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A method for preparing an antimony-doped tin dioxide transparent conductive thin film, characterized by, The method comprises the following steps: (1) forming a metal film of tin / antimony / tin layered sandwich structure on the surface of a substrate by vacuum evaporation; (2) electrolyzing the metal film prepared in step (1) as a working electrode and a platinum electrode as a counter electrode; (3) taking out the metal film after electrolysis for cleaning and then annealing to obtain the antimony-doped tin dioxide transparent conductive film; In step (1), the two tin layers of the metal film have the same amount of tin, and the total amount of tin in the two tin layers is 5-20 times that of the amount of antimony in the antimony layer; In step (2), the electrolyte used in the electrolysis is prepared by mixing deionized water and dimethyl sulfoxide at a volume ratio of 1:(0.5-1.5), and (0.15-0.25) mol / L of citric acid monohydrate is added to the solution.

2. The method for preparing an antimony-doped tin dioxide transparent conductive thin film according to claim 1, characterized in that, In step (2), the voltage of the electrolysis is 2-6V.

3. The method for preparing an antimony-doped tin dioxide transparent conductive thin film according to claim 2, characterized in that, In step (2), the electrolysis voltage is applied for 1-6min.

4. The method for preparing an antimony-doped tin dioxide transparent conductive thin film according to claim 1, characterized in that, In step (3), the annealing temperature is 450-550℃, and the annealing time is 2.5-3.5h.

5. A transparent conductive film of antimony-doped tin dioxide, characterized by, The antimony-doped tin dioxide transparent conductive film prepared by the method of any one of claims 1-4.

6. The antimony doped tin oxide transparent conductive thin film according to claim 5, characterized in that, The visible light transmittance of the antimony-doped tin dioxide transparent conductive film is ≥65%.

7. The antimony doped tin oxide transparent conductive thin film according to claim 5, wherein The sheet resistance of the antimony-doped tin dioxide transparent conductive thin film is ≥180 .

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