High-mobility low-energy-consumption thin film transistor and preparation method thereof

Abstract

The invention relates to the technical field of thin film transistors, in particular to a high-mobility and low-energy-consumption thin film transistor and a preparation method thereof. According to the method, an amorphous indium tin oxide thin film, a molybdenum-doped amorphous indium tin oxide thin film and an amorphous tin oxide thin film are sequentially prepared at the room temperature through the pulse plasma deposition technology, so that a multilayer film of an amorphous indium tin oxide thin film / molybdenum-doped amorphous indium tin oxide thin film / amorphous tin oxide thin film structure is formed to serve as a channel layer; according to the method, an aluminum-doped zinc oxide thin film prepared by an electron beam evaporation technology is used as an electrode, a polytetraethylenephenol thin film prepared by a dip-coating process is used as a dielectric layer, and the method is applied to the development of a top gate structure thin film transistor. The prepared thin film transistor device works in an enhancement mode, and has relatively high saturation mobility (greater than 50cm < 2 > / Vs) and relatively low off-state current (lt; 10-10A) and a threshold voltage close to zero.

Description

Technical Field

[0001] The present invention relates to the technical field of thin film transistors, in particular to a high-mobility and low-energy-consumption thin film transistor and a preparation method thereof. Background Art

[0002] In recent years, thin-film transistors (TFTs) with amorphous indium tin oxide (a-ITO) as the channel layer are expected to break through the technical bottleneck of traditional silicon-based (amorphous silicon or polycrystalline silicon) TFTs due to the advantages of a-ITO thin films such as high carrier mobility, good visible light transparency, and stable amorphous structure, thereby promoting the development of new generation flat panel display technologies such as ultra-high-definition large-size displays, transparent displays, and flexible displays. However, studies have shown that the carrier concentration of a-ITO thin films is too high, causing TFT devices as channel layers to often exhibit a high off-state current and even the devices often work in depletion mode (the threshold voltage is negative, and a negative voltage is required to turn it off in actual applications), resulting in a low switching ratio of the device and excessive energy consumption. In recent years, some research groups have tried to introduce low-electro-negative elements (such as Al, Ga, Ti, etc.) into the a-ITO channel layer or perform subsequent heat treatment on the a-ITO channel layer after preparation (such as annealing in an atmospheric environment, annealing in an oxygen atmosphere, etc.), intending to reduce the carrier concentration by inhibiting the formation of oxygen vacancies in the a-ITO channel layer, effectively reducing the off-state current of the a-ITO TFT device, thereby successfully improving the switching ratio of the device and appropriately reducing the device energy consumption, but this is often at the expense of the mobility of the device. It is well known that in a 240Hz 4K2K (70-inch) active matrix liquid crystal display (AMLCD), the mobility of the TFT is required to be at least 3cm2 / Vs, while in a 240Hz 8K4K ultra-high-definition current-driven active matrix organic light-emitting diode display (AMOLED), the mobility of the TFT is required to be even above 30cm2 / Vs. Therefore, it is necessary to break through the high mobility (>30cm2 / Vs) and low energy consumption (such as: off-state current <10 -10 The development of a-ITO TFT devices with a positive threshold voltage close to 0V is the key to whether they can be successfully applied to the next generation of displays. In fact, by selecting appropriate channel layer film forming technology, improving film forming process conditions, and optimizing channel layer structure design, the performance of a-ITO TFT devices (such as mobility) may also be continuously promoted while reducing device energy consumption.

[0003] Considering the advantages of pulsed plasma deposition (PPD) technology in depositing thin films, such as compactness, flatness, good repeatability, and suitability for preparing multi-element thin film materials, the present invention attempts to prepare an oxide channel layer at room temperature based on the PPD method and apply it to the development of corresponding TFT devices. At the same time, considering the development needs of transparent and flexible displays, TFTs also need to be both transparent and rollable.

[0004] Therefore, the current research focus is on studying the low-temperature preparation of high-mobility, low-energy-consumption transparent rollable TFTs in order to obtain new ideas and effective solutions. Summary of the invention

[0005] In order to solve the above technical problems existing in the prior art, the present invention provides a low-cost, high-mobility, low-energy-consumption thin-film transistor with good electrical performance and low energy consumption, and a preparation method thereof.

[0006] A method for preparing a thin film transistor with high mobility and low energy consumption comprises the following steps:

[0007] (1) On a polyethylene terephthalate (PET) substrate, an amorphous indium tin oxide (a-ITO) film, a molybdenum-doped amorphous indium tin oxide (a-MITO) film, and an amorphous tin oxide (a-SnO2) film are sequentially prepared at room temperature using pulsed plasma deposition (PPD) technology to form a channel layer of an "a-ITO / a-MITO / a-SnO2" structure;

[0008] (2) on the channel layer, using a mask and electron beam evaporation technology to prepare an aluminum-doped zinc oxide (AZO) thin film as a source / drain electrode;

[0009] (3) using an immersion-pulling process, using a precursor solution containing polytetravinylphenol (PVP) to prepare a PVP film as a dielectric layer on the source / drain electrodes and the channel layer;

[0010] (4) On the above-mentioned PVP dielectric layer, an aluminum-doped zinc oxide (AZO) thin film is prepared as a gate electrode by using electron beam evaporation technology in combination with a mask, thereby obtaining the desired product.

[0011] Furthermore, in step (1), when a heterogeneous multilayer film of a three-layer film structure of "a-ITO / a-MITO / a-SnO2" is prepared at room temperature by the PPD method as a channel layer, firstly, an indium tin oxide target is selected to prepare an a-ITO film under the conditions of an operating voltage of 13.2 kV, an operating current of 4.5 to 6.5 mA, an oxygen pressure of 0 Pa, and a deposition time of 3 to 4 min; then, a molybdenum-doped indium tin oxide target is selected to prepare an a-ITO film under the conditions of an operating voltage of 13.2 kV, an operating current of 4.5 to 6.5 mA, an oxygen pressure of 0 Pa, and a deposition time of 3 to 4 min. The a-MITO film was prepared under the conditions of 2kV, working current of 3.0-4.0mA, oxygen pressure of 6.5Pa, and deposition time of 3-4min; then, tin oxide target was selected to deposit a-SnO2 film under the conditions of working voltage of 13.2kV, working current of 2.0-2.5mA, oxygen pressure of 6.5Pa, and deposition time of 2-3min, and the channel layer of "a-ITO / a-MITO / a-SnO2" structure was obtained.

[0012] Furthermore, the indium tin oxide target has a molar ratio of indium to tin of In:Sn=1:1.

[0013] Furthermore, the molybdenum-doped indium tin oxide target has a molar ratio of molybdenum to indium tin of Mo:In:Sn=2:24:24.

[0014] Furthermore, in the step (2), when the electron beam evaporation technology is used to prepare the AZO film as the source / drain electrode, aluminum zinc oxide powder is selected as the evaporation material, the electron gun operates at 7 kV, the current is 130-150 mA, the electron gun is filled with an oxygen atmosphere, and the beam current is 80 sccm, thereby obtaining an AZO film with low surface resistance, high visible light transparency and good flatness as the drain / drain electrode.

[0015] Furthermore, in the step (3), the concentration of the precursor solution of polytetraethylene phenol is 35 mg / mL, the organic solvent is anhydrous ethanol, the pulling speed of the PVP film prepared by the immersion pulling method is 0.5-0.8 mm / s, the number of pulling times is 3 to 6 times, and after pulling, it is baked at 70-90°C for 60-100 minutes to finally obtain the dielectric layer of the PVP film.

[0016] Furthermore, in the step (2), when the electron beam evaporation technology is used to prepare the AZO film as the gate electrode, aluminum zinc oxide powder is selected as the evaporation material, the electron gun operates at 7 kV, the current is 130-150 mA, the electron gun is filled with an oxygen atmosphere, and the beam current is 80 sccm, thereby obtaining an AZO film with low surface resistance, high visible light transparency and good flatness as the gate electrode.

[0017] Furthermore, the aluminum-zinc oxide powder has an aluminum-zinc molar ratio of An:Zn=3:100.

[0018] The high-mobility, low-energy-consumption thin-film transistor prepared by the above-mentioned method for preparing a high-mobility, low-energy-consumption thin-film transistor consists of a substrate, a channel layer, a dielectric layer, a gate electrode, and a source / drain electrode. The substrate is a PET substrate; the channel layer is a multilayer film (a-ITO / a-MITO / a-SnO2) with a heterogeneous three-layer structure composed of an a-ITO film, a Mo-doped a-ITO (a-MITO) film, and an amorphous tin oxide (a-SnO2) film; the dielectric layer is an organic polytetravinylphenol (PVP) film; the source / drain electrode and the gate electrode are aluminum-doped zinc oxide (AZO) films. The thin-film transistor has a high saturation mobility (62.3cm 2 / Vs), a threshold voltage close to zero (0.17V) and a low off-state current (<10 -10 A).

[0019] Compared with the prior art, the technical effects created by the present invention are embodied in:

[0020] (1) While preparing the oxide channel layer by the PPD method, the present invention also takes advantage of the synergistic advantages of improving the film forming process conditions and designing a heterogeneous multi-channel layer structure, ultimately providing a new idea and effective solution for the low-temperature preparation of high-mobility, low-energy consumption transparent rollable TFTs.

[0021] (2) The method of the present invention uses pulse plasma deposition technology to sequentially prepare an amorphous indium tin oxide film, a molybdenum-doped amorphous indium tin oxide film, and an amorphous tin oxide film at room temperature to form a multilayer film of "amorphous indium tin oxide film / molybdenum-doped amorphous indium tin oxide film / amorphous tin oxide film" structure as a channel layer; an aluminum-doped zinc oxide film prepared by electron beam evaporation technology is used as an electrode, and a polytetraethylene phenol film prepared by an immersion pulling process is used as a dielectric layer, and they are applied to the development of top-gate structure thin film transistors.

[0022] (3) The thin film transistor device prepared by the method of the present invention works in the enhancement mode and has a high saturation mobility (62.3 cm 2 / Vs), a threshold voltage close to zero (0.17V) and a low off-state current (<10 -10 A). BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structural cross-section of the thin film transistor in the present invention. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further defined below in conjunction with specific implementation methods, but the scope of protection required is not limited to the description.

[0025] Example 1

[0026] A top-gate TFT is prepared by using PET as a substrate, a three-layer film of "a-ITO / a-MITO / a-SnO2" structure as a channel layer, an organic PVP film as a dielectric layer, and an AZO film as a source / drain electrode and a gate electrode. The structure of the TFT is as follows: Figure 1 As shown, the specific steps are as follows:

[0027] First, a three-layer film of "a-ITO / a-MITO / a-SnO2" structure was prepared as the channel layer. The specific implementation is as follows: (1) an indium tin oxide target (purity 99.99%, indium tin molar ratio of In:Sn=1:1) is selected to prepare an a-ITO film under the conditions of a working voltage of 13.2 kV, a working current of 4.5 mA, an oxygen pressure of 0 Pa, and a deposition time of 4 min; (2) a molybdenum-doped indium tin oxide target (purity 99.99%, molybdenum indium tin molar ratio of Mo:In:Sn=2:24:24) is selected to deposit an a-MITO film on the a-ITO film under the conditions of a working voltage of 13.2 kV, a working current of 3.0 mA, an oxygen pressure of 6.5 Pa, and a deposition time of 4 min; (3) a tin oxide target (purity 99.99%) is selected to deposit an a-SnO2 film on the a-MITO film under the conditions of a working voltage of 13.2 kV, a working current of 2.5 mA, an oxygen pressure of 6.5 Pa, and a deposition time of 3 min. Based on the implementation of steps (1)-(3), a channel layer of "a-ITO / a-MITO / a-SnO2" structure is finally obtained;

[0028] Subsequently, when preparing AZO thin film as source / drain electrode on the channel layer of the "a-ITO / a-MITO / a-SnO2" structure, the specific implementation is as follows: using electron beam evaporation technology, aluminum zinc oxide powder (purity 99.99%, aluminum zinc molar ratio An: Zn = 3: 100) is selected as evaporation material, the electron gun working voltage is set to 7kV, the working current is set to 130mA, the electron gun is filled with oxygen atmosphere, and the beam current is 80sccm, and an aluminum oxide mask is used to prepare AZO thin film as drain / drain electrode;

[0029] Next, prepare Figure 1 The PVP dielectric layer in the substrate is specifically implemented as follows: the substrate including the channel layer and the source / drain electrodes is immersed in a 35 mg / mL polytetraethylene phenol anhydrous ethanol precursor solution, and after being pulled at a speed of 0.5 mm / s, it is baked in an oven at 80°C for 80 minutes to solidify, thereby obtaining a PVP film. The entire pulling and annealing process is repeated 6 times to obtain a PVP channel layer.

[0030] Finally, AZO thin film is prepared as the gate electrode. The specific implementation is: using electron beam evaporation technology, aluminum zinc oxide powder (purity 99.99%, aluminum zinc molar ratio An: Zn = 3: 100) is selected as the evaporation material, the electron gun working voltage is set to 7kV, the working current is 130mA, the electron gun is filled with oxygen atmosphere, and the beam current is 80sccm. The AZO thin film is prepared as the gate electrode using an aluminum oxide mask;

[0031] In this embodiment, the TFT has a relatively high saturation mobility (50.9 cm 2 / Vs), a threshold voltage close to zero (0.90V) and a low off-state current (<10 -10 A).

[0032] Example 2

[0033] A top-gate TFT is prepared by using PET as a substrate, a three-layer film of "a-ITO / a-MITO / a-SnO2" structure as a channel layer, an organic PVP film as a dielectric layer, and an AZO film as a source / drain electrode and a gate electrode. The structure of the TFT is as follows: Figure 1 As shown, the specific steps are as follows:

[0034] First, a three-layer film of "a-ITO / a-MITO / a-SnO2" structure was prepared as the channel layer. The specific implementation is as follows: (1) an indium tin oxide target (purity 99.99%, indium tin molar ratio of In:Sn=1:1) is selected to prepare an a-ITO film under the conditions of a working voltage of 13.2 kV, a working current of 6.5 mA, an oxygen pressure of 0 Pa, and a deposition time of 3 min; (2) a molybdenum-doped indium tin oxide target (purity 99.99%, molybdenum indium tin molar ratio of Mo:In:Sn=2:24:24) is selected to deposit an a-MITO film on the a-ITO film under the conditions of a working voltage of 13.2 kV, a working current of 4.0 mA, an oxygen pressure of 6.5 Pa, and a deposition time of 3 min; (3) a tin oxide target (purity 99.99%) is selected to deposit an a-SnO2 film on the a-MITO film under the conditions of a working voltage of 13.2 kV, a working current of 2.0, an oxygen pressure of 6.5 Pa, and a deposition time of 2 min. Based on the implementation of steps (1)-(3), a channel layer of "a-ITO / a-MITO / a-SnO2" structure is finally obtained;

[0035] Subsequently, when preparing AZO thin film as source / drain electrode on the channel layer of the "a-ITO / a-MITO / a-SnO2" structure, the specific implementation is as follows: using electron beam evaporation technology, aluminum zinc oxide powder (purity 99.99%, aluminum zinc molar ratio An: Zn = 3: 100) is selected as evaporation material, the electron gun working voltage is set to 7kV, the working current is 150mA, the electron gun is filled with oxygen atmosphere, and the beam current is 80sccm, and an aluminum oxide mask is used to prepare AZO thin film as drain / drain electrode;

[0036] Next, prepare Figure 1The PVP dielectric layer in the substrate is specifically implemented as follows: the substrate including the channel layer and the source / drain electrodes is immersed in a 35 mg / mL polytetraethylene phenol anhydrous ethanol precursor solution, and after being pulled at a speed of 0.8 mm / s, it is baked in an oven at 80°C for 80 minutes to solidify, thereby obtaining a PVP film. The entire pulling and annealing process is repeated 3 times to obtain a PVP channel layer.

[0037] Finally, AZO thin film is prepared as the gate electrode. The specific implementation is: using electron beam evaporation technology, aluminum zinc oxide powder (purity 99.99%, aluminum zinc molar ratio An: Zn = 3: 100) is selected as the evaporation material, the electron gun working voltage is set to 7kV, the working current is 150mA, the electron gun is filled with oxygen atmosphere, and the beam current is 80sccm. The AZO thin film is prepared as the gate electrode using an aluminum oxide mask;

[0038] In this embodiment, the TFT has a relatively high saturation mobility (56.7 cm 2 / Vs), a threshold voltage close to zero (0.32V) and a low off-state current (<10 -10 A).

[0039] Example 3

[0040] A top-gate TFT is prepared by using PET as a substrate, a three-layer film of "a-ITO / a-MITO / a-SnO2" structure as a channel layer, an organic PVP film as a dielectric layer, and an AZO film as a source / drain electrode and a gate electrode. The structure of the TFT is as follows: Figure 1 As shown, the specific steps are as follows:

[0041] First, a three-layer film of "a-ITO / a-MITO / a-SnO2" structure was prepared as the channel layer. The specific implementation is as follows: (1) an indium tin oxide target (purity 99.99%, indium tin molar ratio of In:Sn=1:1) is selected to prepare an a-ITO film under the conditions of a working voltage of 13.2 kV, a working current of 5.5 mA, an oxygen pressure of 0 Pa, and a deposition time of 4 min; (2) a molybdenum-doped indium tin oxide target (purity 99.99%, molybdenum indium tin molar ratio of Mo:In:Sn=2:24:24) is selected to deposit an a-MITO film on the a-ITO film under the conditions of a working voltage of 13.2 kV, a working current of 4.0 mA, an oxygen pressure of 6.5 Pa, and a deposition time of 3 min; (3) a tin oxide target (purity 99.99%) is selected to deposit an a-SnO2 film on the a-MITO film under the conditions of a working voltage of 13.2 kV, a working current of 2.0, an oxygen pressure of 6.5 Pa, and a deposition time of 2 min. Based on the implementation of steps (1)-(3), a channel layer of "a-ITO / a-MITO / a-SnO2" structure is finally obtained;

[0042] Subsequently, when preparing AZO thin film as source / drain electrode on the channel layer of the "a-ITO / a-MITO / a-SnO2" structure, the specific implementation is as follows: using electron beam evaporation technology, aluminum zinc oxide powder (purity 99.99%, aluminum zinc molar ratio An: Zn = 3: 100) is selected as evaporation material, the electron gun working voltage is set to 7kV, the working current is 150mA, the electron gun is filled with oxygen atmosphere, and the beam current is 80sccm, and an aluminum oxide mask is used to prepare AZO thin film as drain / drain electrode;

[0043] Next, prepare Figure 1 The PVP dielectric layer in the substrate is specifically implemented as follows: the substrate including the channel layer and the source / drain electrodes is immersed in a 35 mg / mL polytetraethylene phenol anhydrous ethanol precursor solution, and after being pulled at a speed of 0.8 mm / s, it is baked in an oven at 80°C for 80 minutes to solidify, thereby obtaining a PVP film. The entire pulling and annealing process is repeated 3 times to obtain a PVP channel layer.

[0044] Finally, AZO thin film is prepared as the gate electrode. The specific implementation is: using electron beam evaporation technology, aluminum zinc oxide powder (purity 99.99%, aluminum zinc molar ratio An: Zn = 3: 100) is selected as the evaporation material, the electron gun working voltage is set to 7kV, the working current is 150mA, the electron gun is filled with oxygen atmosphere, and the beam current is 80sccm. The AZO thin film is prepared as the gate electrode using an aluminum oxide mask;

[0045] In this embodiment, the TFT has a relatively high saturation mobility (53.1 cm 2 / Vs), a threshold voltage close to zero (0.65V) and a low off-state current (<10 -10 A).

[0046] Example 4

[0047] A top-gate TFT is prepared by using PET as a substrate, a three-layer film of "a-ITO / a-MITO / a-SnO2" structure as a channel layer, an organic PVP film as a dielectric layer, and an AZO film as a source / drain electrode and a gate electrode. The structure of the TFT is as follows: Figure 1 As shown, the specific steps are as follows:

[0048] First, a three-layer film of "a-ITO / a-MITO / a-SnO2" structure was prepared as the channel layer. The specific implementation is as follows: (1) an indium tin oxide target (purity 99.99%, indium tin molar ratio of In:Sn=1:1) is selected to prepare an a-ITO film under the conditions of a working voltage of 13.2 kV, a working current of 6.5 mA, an oxygen pressure of 0 Pa, and a deposition time of 4 min; (2) a molybdenum-doped indium tin oxide target (purity 99.99%, molybdenum indium tin molar ratio of Mo:In:Sn=2:24:24) is selected to deposit an a-MITO film on the a-ITO film under the conditions of a working voltage of 13.2 kV, a working current of 3.0 mA, an oxygen pressure of 6.5 Pa, and a deposition time of 3 min; (3) a tin oxide target (purity 99.99%) is selected to deposit an a-SnO2 film on the a-MITO film under the conditions of a working voltage of 13.2 kV, a working current of 2.0 mA, an oxygen pressure of 6.5 Pa, and a deposition time of 2 min. Based on the implementation of steps (1)-(3), a channel layer of "a-ITO / a-MITO / a-SnO2" structure is finally obtained;

[0049] Subsequently, when preparing AZO thin film as source / drain electrode on the channel layer of the "a-ITO / a-MITO / a-SnO2" structure, the specific implementation is as follows: using electron beam evaporation technology, aluminum zinc oxide powder (purity 99.99%, aluminum zinc molar ratio An: Zn = 3: 100) is selected as evaporation material, the electron gun working voltage is set to 7kV, the working current is 140mA, the electron gun is filled with oxygen atmosphere, and the beam current is 80sccm, and an aluminum oxide mask is used to prepare AZO thin film as drain / drain electrode;

[0050] Next, prepare Figure 1 The PVP dielectric layer in the substrate is specifically implemented as follows: the substrate including the channel layer and the source / drain electrodes is immersed in a 35 mg / mL polytetraethylene phenol anhydrous ethanol precursor solution, and after being pulled at a speed of 0.6 mm / s, it is baked in an oven at 80°C for 80 minutes to solidify, thereby obtaining a PVP film. The entire pulling and annealing process is repeated 4 times to obtain a PVP channel layer.

[0051] Finally, AZO thin film is prepared as the gate electrode. The specific implementation is as follows: using electron beam evaporation technology, aluminum zinc oxide powder (purity 99.99%, aluminum zinc molar ratio An: Zn = 3: 100) is selected as the evaporation material, the electron gun working voltage is set to 7kV, the working current is 140mA, the electron gun is filled with oxygen atmosphere, and the beam current is 80sccm, and an aluminum oxide mask is used to prepare an AZO thin film as the gate electrode;

[0052] In this embodiment, the TFT has a relatively high saturation mobility (62.3 cm 2 / Vs), a threshold voltage close to zero (0.17V) and a low off-state current (<10 -10 A).

[0053] The saturation mobility, off-state current, and threshold voltage of the TFTs obtained in Examples 1-4 are compared:

[0054] Saturation mobility Off-state current Threshold voltage Example 1 <![CDATA[50.9cm 2 / Vs]]> <![CDATA[<10 -10 A]]> 0.90V Example 2 <![CDATA[56.7cm 2 / Vs]]> <![CDATA[<10 -10 A]]> 0.32V Example 3 <![CDATA[53.1cm 2 / Vs]]> <![CDATA[<10 -10 A]]> 0.65V Example 4 <![CDATA[62.3cm 2 / Vs]]> <![CDATA[<10 -10 A]]> 0.17V

[0055] The above data show that the present invention is a low temperature preparation (<100°C) high mobility (>50cm 2 / Vs) low energy consumption (e.g. off-state current <10 -10 A, thin film transistors with a positive threshold voltage close to 0V) provide a feasible solution.

[0056] Finally, it should be pointed out that the above embodiments are only representative examples of the present invention. Obviously, the technical solution of the present invention is not limited to the above embodiments, and there are many variations. All variations that can be directly derived or associated with the content disclosed by ordinary technicians in this field should be considered as the protection scope of the present invention.

Claims

1. A method for preparing a high-mobility and low-energy-consumption thin-film transistor, characterized in that: The steps include: (1) On a polyethylene terephthalate (PET) substrate, amorphous indium tin oxide (a-ITO) thin film, molybdenum-doped amorphous indium tin oxide (a-MITO) thin film, and amorphous tin oxide (a-SnO2) thin film were sequentially prepared at room temperature using pulsed plasma deposition (PPD) technology to form an "a-ITO / a-MITO / a-SnO2” channel layer; (2) on the channel layer, using a mask and electron beam evaporation technology to prepare an aluminum-doped zinc oxide (AZO) thin film as a source / drain electrode; (3) using an immersion-pulling process, using a precursor solution containing polytetravinylphenol (PVP) to prepare a PVP film as a dielectric layer on the source / drain electrodes and the channel layer; (4) On the above-mentioned PVP dielectric layer, an aluminum-doped zinc oxide AZO thin film is prepared as a gate electrode by using electron beam evaporation technology in combination with a mask, thereby obtaining the desired product.

2. The method for preparing a high-mobility and low-energy-consumption thin-film transistor according to claim 1, characterized in that: In the step (1), when a heterogeneous multilayer film of a three-layer film structure of "a-ITO / a-MITO / a-SnO2" is prepared at room temperature by the PPD method as a channel layer, firstly, an indium tin oxide target is selected to prepare an a-ITO film under the conditions of an operating voltage of 13.2 kV, an operating current of 4.5-6.5 mA, an oxygen pressure of 0 Pa, and a deposition time of 3-4 min; then, a molybdenum-doped indium tin oxide target is selected to prepare an a-MITO film under the conditions of an operating voltage of 13.2 kV, an operating current of 3.0-4.0 mA, an oxygen pressure of 6.5 Pa, and a deposition time of 3-4 min; Subsequently, a tin oxide target was selected to deposit an a-SnO2 thin film at an operating voltage of 13.2 kV, an operating current of 2.0-2.5 mA, an oxygen pressure of 6.5 Pa, and a deposition time of 2-3 min, thereby obtaining a channel layer of an "a-ITO / a-MITO / a-SnO2" structure.

3. The method for preparing a high-mobility and low-energy-consumption thin-film transistor according to claim 2, characterized in that: The indium tin oxide target has an indium tin molar ratio of In:Sn=1:

1.

4. The method for preparing a high-mobility and low-energy-consumption thin-film transistor according to claim 2, characterized in that: The molybdenum-doped indium tin oxide target has a molar ratio of molybdenum, indium, and tin of Mo:In:Sn=2:24:

24.

5. The method for preparing a high-mobility and low-energy-consumption thin-film transistor according to claim 1, characterized in that: In the step (2), when the electron beam evaporation technology is used to prepare the AZO film as the source / drain electrode, aluminum zinc oxide powder is selected as the evaporation material, the electron gun operates at 7 kV, the current is 130-150 mA, the electron gun is filled with oxygen atmosphere, and the beam current is 80 sccm, thereby preparing the AZO film as the drain / drain electrode.

6. The method for preparing a high-mobility and low-energy-consumption thin-film transistor according to claim 1, characterized in that: In the step (3), the concentration of the precursor solution of polytetraethylene phenol is 35 mg / mL, the organic solvent is anhydrous ethanol, the pulling speed of the PVP film prepared by the immersion pulling method is 0.5-0.8 mm / s, the number of pulling times is 3 to 6 times, and after pulling, it is baked at 70-90° C. for 60-100 minutes to finally obtain the dielectric layer of the PVP film.

7. The method for preparing a high-mobility and low-energy-consumption thin-film transistor according to claim 1, characterized in that: In the step (2), when electron beam evaporation technology is used to prepare AZO thin film as a gate electrode, aluminum zinc oxide powder is selected as the evaporation material, the electron gun operates at 7 kV, the current is 130-150 mA, the electron gun is filled with oxygen atmosphere, and the beam current is 80 sccm, thereby preparing AZO thin film as a gate electrode.

8. The method for preparing a high-mobility and low-energy-consumption thin-film transistor according to any one of claims 2 and 5, characterized in that: The aluminum-zinc oxide powder has an aluminum-zinc molar ratio of An:Zn=3:

100.

9. A high-mobility, low-energy-consumption thin-film transistor, characterized in that: It consists of a substrate, a channel layer, a dielectric layer, a gate electrode, and source / drain electrodes; the substrate is a PET substrate; the channel layer is a multilayer film (a-ITO / a-MITO / a-SnO2) with a heterogeneous three-layer structure consisting of an a-ITO film, a Mo-doped a-ITO (a-MITO) film, and an amorphous tin oxide (a-SnO2) film; the dielectric layer is an organic polytetravinylphenol (PVP) film; the source / drain electrodes and the gate electrode are aluminum-doped zinc oxide (AZO) films.

10. The high-mobility and low-energy-consumption thin-film transistor according to claim 9, characterized in that: It is prepared by the preparation method according to any one of claims 1 to 8.

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