Gallium indium tin oxide film and preparation method thereof

Abstract

The invention relates to a gallium indium tin oxide film and a preparation method thereof. The preparation method of the gallium indium tin oxide thin film comprises the following steps: carrying out corona treatment on the surface of a substrate to obtain a pretreated substrate; preparing a liquid gallium-indium-tin alloy; and coating the surface of the pretreated substrate with a liquid gallium-indium-tin alloy to obtain the gallium-indium-tin oxide film. The preparation method of the Ga-ITO film has the advantages of being short in flow process, high in controllability, low in energy consumption, high in adjustability and the like, raw materials needed in the preparation process are non-toxic, convenient to collect and reusable, and the preparation cost of the Ga-ITO film can be greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of transparent conductive films, and in particular to a gallium indium tin oxide film and a preparation method thereof. Background Art

[0002] Transparent conductive oxides (TCOs) are of considerable technological interest due to their unique electronic band structure, which makes them both highly conductive and transparent in the visible range. The most prominent application of transparent conductive oxides is as transparent electrodes for liquid crystal displays, organic light-emitting diodes (LEDs) and touch-responsive screens, which can be found in smartphones and flat-panel displays. They are also used in applications such as low-emission windows, optoelectronic devices, solar cells, electrochromic windows, plasmonics and lab-on-chip biosensing.

[0003] Indium tin oxide (ITO) is a widely used TCO that has been used in industry for decades. One of the main disadvantages of ITO is that it is typically deposited using physical vapor deposition techniques, which rely on vacuum technology and high temperature conditions. Due to the ceramic nature of the films, these films are inherently brittle and, therefore, incompatible with flexible electronics. In addition, the indium in ITO is a relatively low-abundance and high-cost element. Although global indium reserves are estimated to be sufficient to support demand in the 21st century, reliance on relatively thick ITO films may ultimately prove to be unsustainable and cost-prohibitive.

[0004] Gallium indium tin oxide film not only reduces the cost of ITO, but also gallium (Ga) as an emerging metal resource has abundant reserves; it further increases the possibility of low-cost large-scale production of gallium indium tin oxide transparent conductive film.

[0005] Therefore, it is very important and necessary to seek a method for preparing a gallium indium tin oxide thin film that can obtain high transparency and reduce the production cost of the gallium indium tin oxide thin film. Summary of the invention

[0006] In order to solve at least one of the above technical problems, the present invention provides a gallium indium tin oxide thin film and a preparation method thereof.

[0007] As one aspect, the present invention provides a method for preparing a gallium indium tin oxide thin film, the preparation method comprising: subjecting a substrate surface to corona treatment to obtain a pretreated substrate; preparing a liquid gallium indium tin alloy; and coating the liquid gallium indium tin alloy on the surface of the pretreated substrate to obtain a gallium indium tin oxide thin film.

[0008] In some embodiments of the present invention, in the step of subjecting the substrate surface to corona treatment to obtain a pre-treated substrate, the substrate surface is subjected to corona treatment by exciting air plasma with a high voltage electric field; wherein the treatment conditions of the high voltage electric field exciting air plasma are as follows: a treatment power of 1500 to 2000 W, a treatment temperature of room temperature, an atmospheric environment, and a treatment time of 20 to 40 s.

[0009] In some embodiments of the present invention, the step of preparing the liquid gallium-indium-tin alloy includes: melting a mixture of gallium metal element, indium metal element and tin metal element to obtain the liquid gallium-indium-tin alloy.

[0010] In some embodiments of the present invention, the liquid gallium-indium-tin alloy includes 0.5-2% Ga, 88-95% In, and 4.5%-10% Sn in terms of atomic percentage.

[0011] In some embodiments of the present invention, the melting point of the liquid gallium-indium-tin alloy is 190-240°C.

[0012] In some embodiments of the present invention, the step of coating the liquid gallium indium tin alloy on the surface of a pretreated substrate to obtain a gallium indium tin oxide film includes: in an aerobic environment, rolling the evenly stirred liquid gallium indium tin alloy from one end of the surface of the pretreated substrate to the other end, removing the liquid gallium indium tin alloy remaining on the surface of the substrate, and obtaining a gallium indium tin oxide film.

[0013] In some embodiments of the present invention, in the step of rolling the evenly stirred liquid gallium indium tin alloy from one end of the pretreated substrate surface to the other end, the rolling speed of the liquid gallium indium tin alloy is 0.5 to 3 cm / min, preferably 1 to 2 cm / min; and / or the number of rolling times is 1 to 60 times, preferably 10 to 30 times.

[0014] In some embodiments of the present invention, the substrate includes at least one of a Si wafer, a SiO2 / Si wafer, a sapphire wafer, a quartz wafer or a polyimide.

[0015] As another aspect, the present invention provides a gallium indium tin oxide thin film obtained by the above-mentioned preparation method.

[0016] As another aspect, the present invention provides an epitaxial wafer, comprising a substrate and an epitaxial layer, wherein the epitaxial layer is the above-mentioned gallium indium tin oxide thin film; wherein the thickness of the gallium indium tin oxide thin film is 0.8 to 60 nm, and / or the band gap width of the gallium indium tin oxide thin film is 3.77 to 4.81 eV.

[0017] The technical solution provided by the embodiment of the present invention has the following advantages:

[0018] The preparation method of the gallium indium tin oxide film of the embodiment of the present invention adopts the method of printing transparent oxide conductive film at low temperature (<250°C) to dope gallium oxide into indium tin oxide, thereby realizing the printing preparation of two-dimensional transparent conductive film under low temperature conditions, and also obtaining a gallium indium tin oxide transparent conductive film with controllable thickness and high transparency; wherein the doping of gallium oxide improves the transparency of the indium tin oxide transparent conductive film. In addition, the preparation method of the gallium indium tin oxide film of the present invention has the advantages of short process, simple steps, strong controllability, low energy consumption and strong adjustability, and the raw materials required in the preparation process are non-toxic, easy to collect and reusable, which can greatly reduce the cost of preparing Ga-ITO film.

[0019] The method for preparing the gallium indium tin oxide thin film according to the embodiment of the present invention can also be performed by directly printing the patterned gallium indium tin oxide thin film on the patterned substrate to be coated.

[0020] The method for preparing the gallium indium tin oxide thin film in the embodiment of the present invention solves the problems of high cost, low efficiency, and complex process faced by the vapor phase epitaxy method in preparing transparent oxide thin films, and is conducive to promoting the large-scale application of transparent oxide thin films in the fields of optoelectronic devices, solar cells, liquid crystal displays, and smart touch systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0023] Figure 1 A flow chart of a method for preparing a gallium indium tin oxide thin film according to an embodiment of the present invention;

[0024] Figure 2 Schematic diagram of rolling printing of a gallium indium tin oxide film on a substrate surface according to an embodiment of the present invention; wherein B1 is a Si / SiO2 wafer; B2 is a gallium indium tin oxide film and a residual liquid alloy coating; B3 is a roller; B4 is gallium indium tin liquid metal ink; and B5 is a rolling printing direction;

[0025] Figure 3 A comparison chart of the transmittance of the gallium indium tin oxide thin film prepared in Example 1 of the present invention, the gallium indium tin oxide thin film prepared in Example 2, and the indium tin oxide thin film prepared in Comparative Example 1;

[0026] Figure 4 This is an optical band gap diagram of the gallium indium tin oxide thin film prepared in Example 1 of the present invention;

[0027] Figure 5 This is an optical band gap diagram of the gallium indium tin oxide film prepared in Example 2 of the present invention. DETAILED DESCRIPTION

[0028] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0030] According to an embodiment of the present invention, a method for preparing a gallium indium tin oxide thin film is provided, the method comprising: (1) subjecting a substrate surface to corona treatment to obtain a pretreated substrate; (2) preparing a liquid gallium indium tin alloy; and (3) coating the liquid gallium indium tin alloy on the surface of the pretreated substrate to obtain a gallium indium tin oxide thin film.

[0031] In some embodiments of the present invention, a flow chart of a method for preparing a gallium indium tin oxide thin film is as follows: Figure 1 As shown, the process specifically includes the following steps: in an oxygen environment, heating a mixture of gallium metal, indium metal, and tin metal until it is melted and stirring evenly; performing corona treatment on the surface of the substrate to be coated by exciting air plasma with a high-voltage electric field; spreading and printing liquid gallium indium tin alloy on the surface of the substrate, and using a glass rod to guide the flow; cleaning the surface of the substrate with cotton dipped in boiling alcohol to obtain a transparent gallium indium tin oxide film.

[0032] In some embodiments of the present invention, in step (1), the surface of the substrate to be coated is subjected to corona treatment by exciting air plasma with a high voltage electric field. The corona treatment can increase the surface energy of the substrate, which is conducive to the adhesion of the nano-Ga-ITO film of the self-limiting oxide layer on the surface of the liquid Ga-In-Sn alloy to the substrate surface.

[0033] In some implementations of the present invention, in step (1), preferably, the conditions for plasma treatment are: setting the low-temperature plasma power to 1500-2000W, for example, 1568W, 1753W, 1829W, 1891W, 1926W, 1987W, etc.; the treatment temperature is room temperature, the treatment environment is an atmospheric environment, and the treatment time is 20-40s, for example, 21s, 26s, 32s, 36s, 39s, etc. Through the above treatment, it is more conducive to enhancing the surface energy of the substrate.

[0034] In some embodiments of the present invention, in step (1), preferably, the substrate includes at least one of a Si wafer, a SiO2 / Si wafer, a sapphire wafer, a quartz wafer, and polyimide (PI).

[0035] In some embodiments of the present invention, in step (1), preferably, the substrate SiO2 / Si wafer is subjected to corona pretreatment, the SiO2 dielectric layer is facing the discharge electrode, and the low-temperature plasma power is set to 1500-2000W, for example, it can be 1561W, 1750W, 1826W, 1893W, 1928W, 1992W, etc.; the processing temperature is room temperature, the processing environment is the atmospheric environment, and the processing time is 20-40s, for example, it can be 23s, 27s, 31s, 35s, 38s, etc.

[0036] In some embodiments of the present invention, in step (2), preferably, the temperature at which the liquid gallium indium tin alloy is uniformly stirred is 190-240°C, for example, it can be 192°C, 198°C, 209°C, 218°C, 229°C, 237°C, etc.; the stirring speed is 300-500r / min, for example, it can be 316r / min, 368r / min, 412r / min, 468r / min, 483r / min, 498r / min, etc.; the stirring time is 10-30min, for example, it can be 11.2min, 14.9min, 18.6min, 23.6min, 29.2min, etc.

[0037] In some embodiments of the present invention, in step (2), preferably, in terms of atomic substance amount percentage, the composition of the gallium indium tin alloy includes: Ga element: 0.5-2%, for example, it can be 0.53%, 0.89%, 1.27%, 1.53%, 1.96%, etc.; In element: 88-95%, for example, it can be 89.2%, 90.6%, 91.8%, 93.6%, 94.9%, etc.; Sn element: 4.5%-10%, for example, it can be 4.62%, 5.68%, 6.8%, 7.6%, 8.9%, 9.8%, etc.; preferably, Ga element: 1%; In element: 94.05%; Sn element: 4.95%. When the atomic substance percentages of Ga, In and Sn in the liquid gallium indium tin alloy are respectively within this range (Ga element: 0.5-2%; In element: 88-95%; Sn element: 4.5%-10%), it is beneficial to prepare a gallium indium tin oxide film with optimal performance. Moreover, adding Ga content can reduce the preparation cost of the gallium indium tin alloy, thereby reducing the preparation cost of the gallium indium tin oxide film.

[0038] In some embodiments of the present invention, in step (2), preferably, the melting point of the gallium indium tin alloy is 190-240°C, for example, 192°C, 203°C, 216°C, 223°C, 231°C, 239°C, etc. The gallium indium tin alloy within this melting point range can enable the oxidation preparation process of the gallium indium tin oxide film to be carried out at room temperature, which is conducive to the preparation of a gallium indium tin oxide film with excellent performance.

[0039] In some embodiments of the present invention, in step (3), the specific operation of coating is: in an aerobic environment, a glass rod is used for guiding, and the evenly stirred liquid gallium indium tin alloy is rolled from one end of the substrate obtained in step (1) to the other end, and after rolling back and forth multiple times; the liquid alloy remaining on the surface of the substrate is removed to obtain a gallium indium tin oxide film (i.e., Ga-ITO film).

[0040] In some embodiments of the present invention, in the specific operation of coating in step (3), a schematic diagram of rolling printing a gallium indium tin oxide film on the surface of a substrate is shown in FIG. Figure 2 As shown, B1 is the Si / SiO2 wafer; B2 is the gallium indium tin oxide film and the residual liquid alloy coating; B3 is the roller; B4 is the gallium indium tin liquid metal ink; and B5 is the rolling printing direction.

[0041] In some embodiments of the present invention, in the specific operation of coating in step (3), preferably, in the step of rolling the uniformly stirred liquid gallium indium tin alloy from one end of the pre-treated substrate surface to the other end, the rolling speed of the liquid alloy is 0.5 to 3 cm / min, for example, it can be 0.5 cm / min, 0.9 cm / min, 1.1 cm / min, 1.8 cm / min, 2.3 cm / min, 2.8 cm / min, etc.; within this speed range, the surface of the gallium indium tin oxide film printed by diversion is flat and free of defects such as cracks and holes. Further preferably, the rolling speed of the liquid alloy is 1 to 2 cm / min, for example, it can be 1.1 cm / min, 1.3 cm / min, 1.6 cm / min, 1.8 cm / min, 1.9 cm / min, etc.

[0042] In some embodiments of the present invention, in the specific operation of coating in step (3), preferably, in the step of rolling the uniformly stirred liquid gallium indium tin alloy from one end of the pre-treated substrate surface to the other end, the number of times the liquid alloy is rolled does not exceed 60 times, for example, it can be 18 times, 29 times, 37 times, 46 times, 58 times, etc.; when the number of rolling does not exceed 60 times, the surface of the printed gallium indium tin oxide film is smooth and defect-free, and the film quality is very high; after the number of rolling exceeds 60 times, the metal residue on the surface of the gallium indium tin oxide gradually increases, and a high-quality gallium indium tin oxide film cannot be obtained. Further preferably, the number of times the liquid alloy is rolled is 10 to 30 times, for example, it can be 12 times, 16 times, 19 times, 23 times, 29 times, etc.

[0043] In some embodiments of the present invention, in the specific operation of coating in step (3), after each rolling is completed, the dielectric layer of the substrate is cleaned with cotton dipped in boiling alcohol until the liquid Ga-In-Sn alloy is completely removed before the next coating is performed.

[0044] In some embodiments of the present invention, an epitaxial wafer is obtained by using the above-mentioned method for preparing an indium tin oxide thin film. The epitaxial wafer includes a substrate and a gallium indium tin oxide thin film attached to the surface of the substrate. Preferably, the thickness of the gallium indium tin oxide (Ga-ITO) thin film is 0.8 to 60 nm, for example, it can be 12.8 nm, 23.7 nm, 36.8 nm, 47.9 nm, 51.6 nm, 59.8 nm, etc.; the bandgap width of the Ga-ITO thin film layer is 3.77 to 4.81 eV, for example, it can be 3.81 eV, 3.92 eV, 4.23 eV, 4.58 eV, 4.79 eV, etc.

[0045] In order to further illustrate the effect of the present invention, specific embodiments are used for illustration below.

[0046] Example 1

[0047] This embodiment provides a Ga 0.01 (In 0.94 Sn 0.05 ) is the preparation of a transparent gallium indium tin oxide conductive film made of liquid metal ink material, the process is as follows Figure 1 As shown, the following steps are included:

[0048] (1) Preparation of Gallium Indium Tin (GaIn 0.01 (In 0.94 Sn 0.05), in terms of atomic mass percentage) Liquid alloy: Use a balance to measure 0.61g Ga, 94.27g In and 5.13g Sn respectively. Place the weighed Ga, In and Sn metal blocks in a clean quartz flat-bottomed crucible, then place the crucible on a heating table with the heating temperature set to 200°C. Place the heating table in an atmospheric environment. After the metal blocks are completely melted, use a glass rod to stir the liquid metal clockwise for 5 minutes to fully mix the liquid metal.

[0049] (2) Corona treatment of electronic substrate surface: A Si / SiO2 wafer with a diameter of 2 inches, a Si substrate thickness of 500 μm and a SiO2 layer thickness of 300 nm was placed on the discharge roller of a low-temperature plasma instrument, wherein the SiO2 dielectric layer was facing the discharge electrode. The low-temperature plasma power was set to 500 W, the treatment temperature was room temperature, the treatment conditions were: a local pure oxygen environment at the discharge roller, and the treatment time was 30 s.

[0050] (3) Printing of GaInO transparent conductive film: After the corona treatment, the SiO2 / Si electronic substrate is quickly transferred to the heating table and the corona-treated SiO2 dielectric layer is coated with liquid GaInT alloy. The liquid metal is evenly scraped onto the surface of the SiO2 dielectric layer using a roller. The scraping process is shown in the figure. Figure 2 As shown, the temperature of the heating stage was maintained at 200° C. After standing for 3 min, the liquid metal was removed from the surface of the dielectric layer, and then cleaned with cotton dipped in boiling alcohol until the liquid metal was completely removed.

[0051] (4) After repeating step (3) four times, a gallium indium tin oxide thin film layer with a thickness of 8 nm is printed and deposited on the surface of the Si / SiO2 wafer to obtain a gallium indium tin oxide thin film.

[0052] Example 2

[0053] This embodiment provides a Ga 0.005 (In 0.945 Sn 0.050 ) is the preparation of a transparent gallium indium tin oxide conductive film made of liquid metal ink material, the process is as follows Figure 1 As shown, the following steps are included:

[0054] (1) Preparation of Gallium Indium Tin (GaIn 0.005 (In 0.945 Sn 0.050), measured as percentage of atomic substance) Liquid alloy: Use a balance to measure 0.30g Ga, 94.55g In and 5.15g Sn respectively. Place the weighed Ga, In and Sn metal blocks in a clean quartz flat-bottomed crucible, then place the crucible on a heating table with the heating temperature set to 200°C. Place the heating table in an atmospheric environment. After the metal blocks are completely melted, stir the liquid metal clockwise for 5 minutes with a glass rod to fully mix the liquid metal.

[0055] (2) Corona treatment of electronic substrate surface: A Si / SiO2 wafer with a diameter of 2 inches, a Si substrate thickness of 500 μm and a SiO2 layer thickness of 300 nm was placed on the discharge roller of a low-temperature plasma instrument, wherein the SiO2 dielectric layer was facing the discharge electrode. The low-temperature plasma power was set to 500 W, the treatment temperature was room temperature, the treatment conditions were: a local pure oxygen environment at the discharge roller, and the treatment time was 30 s.

[0056] (3) Printing of GaInO transparent conductive film: After the corona treatment, the SiO2 / Si electronic substrate is quickly transferred to the heating table and the corona-treated SiO2 dielectric layer is coated with liquid GaInT alloy. The liquid metal is evenly scraped onto the surface of the SiO2 dielectric layer using a roller. The scraping process is shown in the figure. Figure 2 As shown, the temperature of the heating stage was maintained at 200° C. After standing for 3 min, the liquid metal was removed from the surface of the dielectric layer, and then cleaned with cotton dipped in boiling alcohol until the liquid metal was completely removed.

[0057] (4) After repeating step (3) four times, a gallium indium tin oxide thin film layer with a thickness of 8 nm is printed and deposited on the surface of the Si / SiO2 wafer to obtain a gallium indium tin oxide thin film.

[0058] Comparative Example 1

[0059] This comparative example provides a method of 0.95 Sn 0.05 Preparation of transparent indium tin oxide conductive film for liquid metal ink material, the process is as follows Figure 1 As shown, the following steps are included:

[0060] (1) Preparation of Indium Tin 0.95 Sn 0.05 , measured as percentage of atomic substance) Liquid alloy: Use a balance to weigh 94.84g In and 5.16g Sn respectively. Place the weighed In and Sn metal blocks in a clean quartz flat-bottomed crucible, then place the crucible on a heating table with the heating temperature set to 240°C. Place the heating table in an atmospheric environment. After the metal blocks are completely melted, use a glass rod to stir the liquid metal clockwise for 5 minutes to fully mix the liquid metal.

[0061] (2) Corona treatment of electronic substrate surface: A Si / SiO2 wafer with a diameter of 2 inches, a Si substrate thickness of 500 μm and a SiO2 layer thickness of 300 nm was placed on the discharge roller of a low-temperature plasma instrument, wherein the SiO2 dielectric layer was facing the discharge electrode. The low-temperature plasma power was set to 500 W, the treatment temperature was room temperature, the treatment conditions were: a local pure oxygen environment at the discharge roller, and the treatment time was 30 s.

[0062] (3) Printing of indium tin oxide transparent conductive film: After the corona treatment, the SiO2 / Si electronic substrate is quickly transferred to the heating table and the corona-treated SiO2 dielectric layer is coated with liquid indium tin alloy. The liquid metal is evenly scraped onto the surface of the SiO2 dielectric layer using a roller. The scraping process diagram is shown in the figure. Figure 2 As shown, the temperature of the heating stage was maintained at 240° C. After standing for 3 min, the liquid metal was removed from the surface of the dielectric layer, and then cleaned with cotton dipped in boiling alcohol until the liquid metal was completely removed.

[0063] (4) After repeating step (3) four times, an indium tin oxide thin film layer with a thickness of 8 nm was printed and deposited on the surface of the Si / SiO2 wafer to obtain an indium tin oxide thin film.

[0064] Test Example 1

[0065] 1. Bandgap width: The bandgap width of the gallium indium tin oxide thin film prepared in Examples 1 and 2 was measured using a UV-vis spectrophotometer. The parameters of the UV-vis spectrophotometer were as follows: the absorption spectrum wavelength was set to 200 to 800 nm, and the scanning step was 5 nm / s.

[0066] Figure 3 It is a comparison chart of the transmittance of the gallium indium tin oxide thin film prepared in Example 1, the gallium indium tin oxide thin film prepared in Example 2 and the indium tin oxide thin film prepared in Comparative Example 1; wherein, "ITO" represents the indium tin oxide thin film prepared in Comparative Example 1, "Ga0.5" represents the gallium indium tin oxide thin film prepared in Example 2, and "Ga1.0" represents the gallium indium tin oxide thin film prepared in Example 1.

[0067] Figure 4 This is an optical band gap diagram of the gallium indium tin oxide thin film prepared in Example 1; wherein, “Ga1.0” represents the gallium indium tin oxide thin film prepared in Example 1.

[0068] Figure 5 This is an optical band gap diagram of the gallium indium tin oxide thin film prepared in Example 2; wherein, “Ga0.5” represents the gallium indium tin oxide thin film prepared in Example 2.

[0069] according to Figures 3 to 5 The data in are analyzed as follows:

[0070] (1) From Figure 3 It can be seen that the light transmission critical wavelength of the gallium indium tin oxide thin film prepared in Example 1 and Example 2 is 340nm, while the light absorption critical wavelength of the indium tin oxide thin film prepared in Comparative Example 1 is 400nm.

[0071] (2) From Figure 4 and Figure 5 It can be seen that the bandgap widths of the gallium indium tin oxide films prepared in Example 1 and Example 2 are 4.81 eV and 4.46 eV respectively. After testing, the bandgap width of the ITO film prepared in Comparative Example 1 is 3.77 eV.

[0072] 2. Resistivity test: The resistivity of the gallium indium tin oxide film prepared in Example 1 was measured using a four-probe method. The parameters of the probes used were as follows: model Guangzhou Four Probe Technology FT-203, C=6.280, F=1.001.

[0073] The test results are as follows: the sheet resistance of the gallium indium tin oxide thin film of Example 1 is 16.82 kΩ / □, and the sheet resistance of the indium tin oxide thin film of Comparative Example 1 is 8.08 kΩ / □.

[0074] In summary, the gallium indium tin oxide film and the preparation method thereof provided in the embodiment of the present invention prepare a transparent conductive film by melting the gallium indium tin alloy in an aerobic environment and then directly coating it on the surface of a substrate. The present invention rolls liquid Ga-In-Sn alloy on the surface of the substrate, and then spontaneously oxidizes it, so that a large-area, high-quality, patterned, and thickness-controlled Ga-ITO transparent conductive film can be obtained on the surface of the substrate. The preparation method of the gallium indium tin oxide film of the embodiment of the present invention has the characteristics of simple steps and low cost.

[0075] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0076] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments described herein, but should conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a gallium indium tin oxide thin film, characterized in that: The preparation method comprises: Performing corona treatment on the surface of the substrate to obtain a pre-treated substrate; Preparation of liquid gallium-indium-tin alloy; The liquid gallium indium tin alloy is coated on the surface of the pre-treated substrate to obtain a gallium indium tin oxide film.

2. The method for preparing the gallium indium tin oxide thin film according to claim 1, characterized in that: In the step of subjecting the substrate surface to corona treatment to obtain a pretreated substrate, the substrate surface is subjected to corona treatment by exciting air plasma with a high voltage electric field; The processing conditions of the high-voltage electric field exciting air plasma method are as follows: processing power is 1500-2000W, processing temperature is room temperature, processing environment is atmospheric environment, and processing time is 20-40s.

3. The method for preparing a gallium indium tin oxide thin film according to claim 1 or 2, characterized in that: The step of preparing the liquid gallium-indium-tin alloy comprises: melting a mixture of gallium metal element, indium metal element and tin metal element to obtain the liquid gallium-indium-tin alloy.

4. The method for preparing the gallium indium tin oxide thin film according to claim 3, characterized in that: Calculated by atomic percentage, the liquid gallium-indium-tin alloy includes 0.5-2% Ga, 88-95% In, and 4.5%-10% Sn.

5. The method for preparing the gallium indium tin oxide thin film according to claim 4, characterized in that: The melting point of the liquid gallium-indium-tin alloy is 190-240°C.

6. The method for preparing a gallium indium tin oxide thin film according to any one of claims 1 to 5, characterized in that: The step of coating the liquid gallium indium tin alloy on the surface of the pre-treated substrate to obtain a gallium indium tin oxide film comprises: In an oxygen environment, the evenly stirred liquid gallium indium tin alloy is rolled from one end of the pre-treated substrate surface to the other end, and the liquid gallium indium tin alloy remaining on the substrate surface is removed to obtain a gallium indium tin oxide film.

7. The method for preparing the gallium indium tin oxide thin film according to claim 6, characterized in that: In the step of rolling the uniformly stirred liquid gallium indium tin alloy from one end of the pre-treated substrate surface to the other end, The rolling speed of the liquid gallium-indium-tin alloy is 0.5 to 3 cm / min, preferably 1 to 2 cm / min; And / or, the number of scrolling is 1 to 60 times, preferably 10 to 30 times.

8. The method for preparing a gallium indium tin oxide thin film according to any one of claims 1 to 7, characterized in that: The substrate includes at least one of a Si wafer, a SiO2 / Si wafer, a sapphire wafer, a quartz wafer or a polyimide.

9. A gallium indium tin oxide thin film obtained by the preparation method according to any one of claims 1 to 8.

10. An epitaxial wafer, characterized in that: The epitaxial wafer comprises a substrate and an epitaxial layer, and the epitaxial layer is the gallium indium tin oxide thin film according to claim 9; Wherein, the thickness of the gallium indium tin oxide film is 0.8-60 nm, and / or the band gap width of the gallium indium tin oxide film is 3.77-4.81 eV.

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