Tin oxide-based thin film and method for producing the same

Abstract

This application relates to a tin oxide-based thin film and a method for preparing the same. The tin oxide-based thin film of this application comprises a material having an amorphous structure with the following general chemical formula: M x Sn 1‑x O 2(1‑y) F 2y Where 0.001≤x≤0.2, 0≤y≤0.1, and M is a doping metal element with an ionic radius less than or equal to 120 pm. Compared to substitutional doping in traditional semiconductor materials, the tin oxide-based thin film in this application uses a metal element with an ionic radius less than or equal to 120 pm for doping. Furthermore, the amorphous structure of this material has a low interstitial defect formation energy, and these defects mainly exist as interstitial defects in the thin film, reducing structural defects and improving the electrical performance of the tin oxide-based thin film. Simultaneously, the doping metal element located at the interstitial sites acts as a shallow donor in the thin film, further enhancing its electrical performance. The tin oxide-based thin film of this application exhibits better electrical performance than traditional tin oxide thin films.

Description

Technical Field

[0001] This application relates to the field of conductive thin film technology, and in particular to a tin oxide-based thin film and its preparation method. Background Technology

[0002] Indium oxide (In₂O₃)-based transparent conductive materials are currently the most commonly used transparent conductive oxides (TCOs) in industry. However, indium metal is relatively rare, and In₂O₃ exhibits instability in reducing atmospheres and relatively high humidity environments. In recent years, tin oxide-based TCO thin films have been developed and utilized as alternatives to In₂O₃ thin films, and are widely used in technologies such as solar cells, touch screens, thin-film transistors, and semiconductor lasers. However, traditional tin oxide-based thin films have relatively poor electrical properties. Summary of the Invention

[0003] Therefore, it is necessary to provide a tin oxide-based thin film and its preparation method. The tin oxide-based thin film of this application has good electrical properties.

[0004] In a first aspect, this application provides a tin oxide-based thin film, comprising a material having an amorphous structure having the following general chemical formula:

[0005] M x Sn 1-x O 2(1-y) F 2y Where 0.001≤x≤0.2, 0≤y≤0.1, and M is a doped metal element with an ionic radius less than or equal to 120 pm.

[0006] In some embodiments, M includes at least one of alkali metal elements, alkaline earth metal elements, lanthanide metal elements, Y, Ti, Mn, Fe, Co, Ni, Cu, Zn, Nd, Ta, Nb, Sb, W, Mo, and Cd.

[0007] In some embodiments, M comprises one or more of Li and Zn, Mg, Ca, Ba, Y and La, and the work function of the tin oxide-based thin film is greater than 3.4 eV and less than 4.5 eV.

[0008] In some embodiments, M is Li and y=0, and the work function of the tin oxide-based thin film is greater than 3.4 eV and less than 3.66 eV.

[0009] In some embodiments, M is one or more of Zn, Mg, Ca, Ba, Y and La, and the work function of the tin oxide-based thin film is greater than 3.66 eV and less than 4.5 eV.

[0010] In some embodiments, the thickness of the tin oxide-based thin film is 1 nm to 200 nm.

[0011] Secondly, this application provides a method for preparing any of the above-described tin oxide-based thin films, comprising:

[0012] A tin oxide-based thin film is prepared on a substrate, the tin oxide-based thin film comprising a material having an amorphous structure with the following general chemical formula: M x Sn 1-x O 2(1-y) F 2y Where 0.001≤x≤0.2, 0≤y≤0.1, and M is a doped metal element with an ionic radius less than or equal to 120 pm.

[0013] In some embodiments, preparing a tin oxide-based thin film on a substrate includes:

[0014] The tin oxide-based thin film is deposited using a tin oxide target containing doped metal element M, or using a tin oxide target containing doped metal element M and fluorine element.

[0015] In some embodiments, M includes at least one of alkali metal elements, alkaline earth metal elements, lanthanide metal elements, Y, Ti, Mn, Fe, Co, Ni, Cu, Zn, Nd, Ta, Nb, Sb, W, Mo, and Cd.

[0016] In some embodiments, the deposition temperature is 20°C to 300°C.

[0017] In some embodiments, the deposition time is 2 min to 100 min.

[0018] In some embodiments, the deposition power is 0.2 W / cm². 2 ~3W / cm 2 .

[0019] The aforementioned tin oxide-based thin films include materials with an amorphous structure having the following general chemical formula: M x Sn 1-x O 2(1-y) F 2y Where 0.001≤x≤0.2, 0≤y≤0.1, and M is a doping metal element with an ionic radius less than or equal to 120 pm. Compared to substitutional doping in traditional semiconductor materials, the tin oxide-based thin film of this application uses a metal element with an ionic radius less than or equal to 120 pm for doping. Furthermore, the amorphous structure of this material has a low interstitial defect formation energy, and these defects mainly exist as interstitial defects in the thin film, which can reduce structural defects in the tin oxide-based thin film and improve its electrical performance. Simultaneously, the doping metal element at the interstitial sites acts as a shallow donor in the thin film, further enhancing its electrical performance. Attached Figure Description

[0020] Figure 1 The Li prepared in Example 1 and Comparative Example 1 of this application 0.12 Sn 0.88 XRD pattern of tin oxide-based thin films;

[0021] Figure 2 The Mg prepared in Example 2 and Comparative Example 2 of this application 0.05 Sn 0.95 XRD pattern of tin oxide-based thin films;

[0022] Figure 3 The Zn prepared in Example 3 and Comparative Example 3 of this application 0.08 Sn 0.92 XRD pattern of tin oxide-based thin films;

[0023] Figure 4 The Y prepared in Example 4 and Comparative Example 4 of this application 0.03 Sn 0.97 XRD pattern of tin oxide-based thin films;

[0024] Figure 5 The La prepared in Example 5 and Comparative Example 5 of this application 0.04 Sn 0.96 XRD pattern of tin oxide-based thin films;

[0025] Figure 6 The Li prepared in Example 7 of this application 0.01 Zn 0.01 Sn 0.98 XRD pattern of tin oxide-based thin films;

[0026] Figure 7 The Li prepared in Example 1 of this application 0.12 Sn 0.88 UPS diagram of tin oxide-based thin films;

[0027] Figure 8 The Mg prepared in Example 2 of this application 0.05 Sn 0.95 UPS diagram of tin oxide-based thin films;

[0028] Figure 9 Zn prepared in Example 3 of this application 0.08 Sn 0.92 UPS diagram of tin oxide-based thin films;

[0029] Figure 10 Y prepared in Example 4 of this application 0.03 Sn 0.97 UPS diagram of tin oxide-based thin films;

[0030] Figure 11 The Li prepared in Example 7 of this application 0.01 Zn 0.01 Sn 0.98 UPS diagram of tin oxide-based thin films;

[0031] Figure 12 SnO, the control group provided in this application 0.98 F 0.02 UPS diagram of tin oxide-based thin films. Detailed Implementation

[0032] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0034] One embodiment of this application provides a tin oxide-based thin film, comprising a material having an amorphous structure with the following general chemical formula: M x Sn 1-x O 2(1-y) F 2y Where 0.001≤x≤0.2, 0≤y≤0.1, and M is a doped metal element with an ionic radius less than or equal to 120 pm.

[0035] The aforementioned tin oxide-based thin films include materials with an amorphous structure having the following general chemical formula: M x Sn 1-x O 2(1-y) F 2yWhere 0.001≤x≤0.2, 0≤y≤0.1, and M is a doping metal element with an ionic radius less than or equal to 120 pm. Compared to substitutional doping in traditional semiconductor materials, the tin oxide-based thin film in this application uses a metal element with an ionic radius less than or equal to 120 pm for doping. Furthermore, the amorphous structure of this material has a low interstitial defect formation energy, and these defects mainly exist as interstitial defects in the thin film, reducing structural defects and improving the electrical performance of the tin oxide-based thin film. Simultaneously, the doping metal element at the interstitial sites acts as a shallow donor in the thin film, further enhancing its electrical performance. The tin oxide-based thin film of this application exhibits better electrical performance than traditional tin oxide thin films.

[0036] Optionally, x can be 0.001, 0.002, 0.003, 0.004, 0.005, 0.008, 0.01, 0.015, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.195, or 0.2.

[0037] Optionally, y can be 0, 0.0001, 0.001, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.091, 0.092, 0.093, 0.094, 0.095, 0.099, 0.0999, or 0.1.

[0038] Optionally, the ionic radius of M is ≤120 pm if 50 pm ≤ M. Further optionally, the ionic radius of M is 50 pm, 52 pm, 54 pm, 56 pm, 58 pm, 60 pm, 62 pm, 64 pm, 66 pm, 68 pm, 70 pm, 72 pm, 74 pm, 76 pm, 78 pm, 80 pm, 82 pm, 84 pm, 86 pm, 88 pm, 90 pm, 92 pm, 94 pm, 96 pm, 98 pm, 100 pm, 102 pm, 104 pm, 106 pm, 108 pm, 110 pm, 112 pm, 114 pm, 116 pm, 118 pm, or 120 pm.

[0039] In some embodiments, the tin oxide-based thin film is composed of a material having an amorphous structure with the following general chemical formula: M x Sn 1-x O 2(1-y) F 2y Where 0.001≤x≤0.2, 0≤y≤0.1, and M is a doped metal element with an ionic radius less than or equal to 120 pm.

[0040] In some embodiments, the tin oxide-based thin film has an amorphous structure. Based on the tin oxide-based thin film with the above-described composition, the amorphous tin oxide-based thin film exhibits superior electrical properties compared to monocrystalline or polycrystalline tin oxide-based thin films. The amorphous structure of the tin oxide-based thin film is more conducive to strain relaxation caused by interstitial impurities compared to polycrystalline or monocrystalline structures, thus achieving a higher interstitial impurity concentration, significantly increasing the carrier concentration of the film, reducing the resistivity of the film, and resulting in superior conductivity for the amorphous tin oxide-based thin film.

[0041] In some embodiments, M includes at least one selected from alkali metals, alkaline earth metals, lanthanides, Y, Ti, Mn, Fe, Co, Ni, Cu, Zn, Nd, Ta, Nb, Sb, W, Mo, and Cd. Optionally, M includes at least one selected from Li, Mg, Sc, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sb, Y, La, and Ta.

[0042] In some embodiments, M comprises one or more of Li and Zn, Mg, Ca, Ba, Y and La, and the work function of the tin oxide-based thin film is greater than 3.4 eV and less than 4.5 eV. When tin oxide is co-doped with one or more of Li and Zn, Mg, Ca, Ba, Y and La, tin oxide-based thin films with tunable work functions over a wide range can be obtained.

[0043] In some embodiments, M is Li and y=0, and the work function of the tin oxide-based thin film is greater than 3.4 eV and less than 3.66 eV. When M is Li and y=0, a work function higher than that of the conventional SnO composition can be obtained. 0.98 F 0.02 Tin oxide-based thin films (FTO) with low tin oxide content.

[0044] In some embodiments, M is one or more of Zn, Mg, Ca, Ba, Y, and La, and the work function of the tin oxide-based thin film is greater than 3.66 eV and less than 4.5 eV. When tin oxide is doped with one or more of Zn, Mg, Ca, Ba, Y, and La, a tin oxide-based thin film with a higher work function than the FTO thin film can be obtained.

[0045] Using metal elements as dopants, different metal ion structures and radii will have different effects on the work function of the thin film. Doping with Li can decrease the work function of tin oxide-based thin films, while doping with Zn, Mg, Ca, Ba, Y, or La can increase the work function. This makes the work function of tin oxide-based thin films adjustable within a certain range, which can expand the application range of tin oxide-based thin films.

[0046] In some embodiments, the thickness of the tin oxide-based thin film is 1 nm to 200 nm. Within this thickness range of the tin oxide-based thin film, M x Sn 1-x O 2(1-y) F 2y The material maintains its amorphous structure well; however, when the thickness of the tin oxide-based thin film is too large, M... x Sn 1- x O 2(1-y) F 2y The material may crystallize, leading to a decrease in the electrical properties of the thin film. Optionally, the thickness of the tin oxide-based thin film is 1 nm, 2 nm, 3 nm, 5 nm, 7 nm, 9 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, or 200 nm.

[0047] Another embodiment of this application provides a method for preparing any of the above-mentioned tin oxide-based thin films, comprising: preparing a tin oxide-based thin film on a substrate, wherein the tin oxide-based thin film comprises a material having an amorphous structure having the following general chemical formula: M x Sn 1- x O 2(1-y) F 2y Where 0.001≤x≤0.2, 0≤y≤0.1, and M is a doped metal element with an ionic radius less than or equal to 120 pm.

[0048] In some embodiments, preparing a tin oxide-based thin film on a substrate includes: depositing a tin oxide-based thin film using a tin oxide target containing a doped metal element M, or depositing a tin oxide-based thin film using a tin oxide target containing both a doped metal element M and a fluorine element.

[0049] In some embodiments, M includes at least one selected from alkali metals, alkaline earth metals, lanthanides, Y, Ti, Mn, Fe, Co, Ni, Cu, Zn, Nd, Ta, Nb, Sb, W, Mo, and Cd. Optionally, M includes at least one selected from Li, Mg, Sc, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sb, Y, La, and Ta.

[0050] In some embodiments, the deposition temperature is 20°C to 300°C. The crystallization temperature of tin oxide-based thin films is above 400°C. Compared to polycrystalline or single-crystal structures, the amorphous structure of tin oxide-based thin films is more conducive to strain relaxation caused by interstitial impurities, thus achieving a higher interstitial impurity concentration, significantly increasing the carrier concentration of the film, and reducing the resistivity. Therefore, tin oxide-based thin films with an amorphous structure exhibit superior conductivity. Tin oxide-based thin films with an amorphous structure can be prepared within this temperature range. Optionally, the deposition temperature is 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃, 110℃, 120℃, 130℃, 150℃, 160℃, 180℃, 200℃, 210℃, 220℃, 230℃, 250℃, 260℃, 280℃, 290℃, or 300℃.

[0051] In some embodiments, the deposition time is 2 min to 100 min. By controlling the deposition time, the thickness of the tin oxide-based thin film can be controlled. Within this deposition time range, a tin oxide-based thin film of suitable thickness can be obtained, enabling the tin oxide-based thin film to simultaneously possess good conductivity and transparency. Optionally, the deposition time is 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 12 min, 15 min, 18 min, 20 min, 22 min, 25 min, 28 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, 65 min, 70 min, 72 min, 75 min, 78 min, 80 min, 82 min, 85 min, 88 min, 90 min, 92 min, 95 min, 98 min, 99 min, or 100 min.

[0052] In some embodiments, the deposition power is 0.2 W / cm². 2 ~3W / cm 2 It is understood that the deposition power represents the power supply of the deposition equipment corresponding to a unit area of ​​target material. Within this deposition power range, tin oxide-based thin films with good film formation can be obtained. Optionally, the deposition power is 0.2 W / cm². 2 0.3W / cm 2 0.4W / cm 2 0.5W / cm 2 0.6W / cm 2 0.7W / cm 2 0.8W / cm 2 0.9W / cm2 1W / cm 2 1.1W / cm 2 1.2W / cm 2 1.3W / cm 2 1.4W / cm 2 1.5W / cm 2 1.6W / cm 2 1.7W / cm 2 1.8W / cm 2 1.9W / cm 2 2W / cm 2 2.1W / cm 2 2.2W / cm 2 2.3W / cm 2 2.4W / cm 2 2.5W / cm 2 2.6W / cm 2 2.7W / cm 2 2.8W / cm 2 2.9W / cm 2 Or 3W / cm 2 .

[0053] In some embodiments, tin oxide-based thin films are prepared by magnetron sputtering or reactive plasma deposition.

[0054] In some embodiments, the gas atmosphere for magnetron sputtering or reactive plasma deposition is a mixture of inert and oxidizing gases.

[0055] In some embodiments, the oxidizing gas includes oxygen.

[0056] In some embodiments, the inert gas includes at least one of helium, neon, argon, krypton, and xenon.

[0057] In some embodiments, the gas pressure of the mixed gas during the deposition process is 0.1 Pa to 10 Pa. Optionally, the gas pressure of the mixed gas is 0.1 Pa, 0.2 Pa, 0.5 Pa, 1 Pa, 1.5 Pa, 2 Pa, 2.5 Pa, 3 Pa, 3.5 Pa, 4 Pa, 4.5 Pa, 5 Pa, 5.5 Pa, 6 Pa, 6.5 Pa, 7 Pa, 7.5 Pa, 8 Pa, 8.5 Pa, 9 Pa, 9.5 Pa, or 10 Pa.

[0058] In some embodiments, the flow ratio of the inert gas to the oxidizing gas is (1~30):1. Optionally, the flow ratio of the inert gas to the oxidizing gas is 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 21:1, 22:1, 23:1, 24:1, 25:1, 26:1, 27:1, 28:1, 29:1, or 30:1.

[0059] The following are specific embodiments.

[0060] Example 1

[0061] The tin oxide-based thin film prepared in this embodiment has a composition of Li. 0.12 Sn 0.88 O.

[0062] The method for preparing the tin oxide-based thin film in this embodiment is as follows:

[0063] (1) A tin oxide-based thin film was deposited using a magnetron sputtering device. The target material for magnetron sputtering was Li-doped tin oxide ceramic. The substrate was placed in the reaction chamber of the magnetron sputtering device, the reaction chamber was evacuated, and the temperature of the substrate was controlled at 180°C.

[0064] (2) Argon and oxygen are introduced into the reaction chamber to make the gas pressure in the reaction chamber 0.4 Pa, and the power of magnetron sputtering is controlled to be 1.48 W / cm. 2 Tin oxide-based thin films were deposited for 27 minutes.

[0065] Example 2

[0066] The tin oxide-based thin film prepared in this embodiment has a composition of Mg. 0.05 Sn 0.95 O.

[0067] The method for preparing the tin oxide-based thin film in this embodiment is as follows:

[0068] (1) A tin oxide-based thin film was deposited using a magnetron sputtering device. The target material for magnetron sputtering was Mg-doped tin oxide ceramic. The substrate was placed in the reaction chamber of the magnetron sputtering device, the reaction chamber was evacuated, and the temperature of the substrate was controlled at 180°C.

[0069] (2) Argon and oxygen are introduced into the reaction chamber to make the gas pressure in the reaction chamber 0.4 Pa, and the power of magnetron sputtering is controlled to be 1.48 W / cm. 2 Tin oxide-based thin films were deposited for 27 minutes.

[0070] Example 3

[0071] The tin oxide-based thin film prepared in this embodiment has a composition of Zn. 0.08 Sn 0.92 O.

[0072] The method for preparing the tin oxide-based thin film in this embodiment is as follows:

[0073] (1) A tin oxide-based thin film was deposited using a magnetron sputtering device. The target material for magnetron sputtering was Zn-doped tin oxide ceramic. The substrate was placed in the reaction chamber of the magnetron sputtering device, the reaction chamber was evacuated, and the temperature of the substrate was controlled at 180°C.

[0074] (2) Argon and oxygen are introduced into the reaction chamber to make the gas pressure in the reaction chamber 0.4 Pa, and the power of magnetron sputtering is controlled to be 1.48 W / cm. 2 Tin oxide-based thin films were deposited for 27 minutes.

[0075] Example 4

[0076] The tin oxide-based thin film prepared in this embodiment has the following composition: Y 0.03 Sn 0.97 O.

[0077] The method for preparing the tin oxide-based thin film in this embodiment is as follows:

[0078] (1) A tin oxide-based thin film was deposited using a magnetron sputtering device. The target material for magnetron sputtering was Y-doped tin oxide ceramic. The substrate was placed in the reaction chamber of the magnetron sputtering device, the reaction chamber was evacuated, and the temperature of the substrate was controlled at 180°C.

[0079] (2) Argon and oxygen are introduced into the reaction chamber to make the gas pressure in the reaction chamber 0.4 Pa, and the power of magnetron sputtering is controlled to be 1.48 W / cm. 2 Tin oxide-based thin films were deposited for 27 minutes.

[0080] Example 5

[0081] The tin oxide-based thin film prepared in this embodiment has a composition of La. 0.04 Sn 0.96 O.

[0082] The method for preparing the tin oxide-based thin film in this embodiment is as follows:

[0083] (1) A tin oxide-based thin film was deposited using a magnetron sputtering device. The target material for magnetron sputtering was La-doped tin oxide ceramic. The substrate was placed in the reaction chamber of the magnetron sputtering device, the reaction chamber was evacuated, and the temperature of the substrate was controlled at 180°C.

[0084] (2) Argon and oxygen are introduced into the reaction chamber to make the gas pressure in the reaction chamber 0.4 Pa, and the power of magnetron sputtering is controlled to be 1.48 W / cm. 2 Tin oxide-based thin films were deposited for 27 minutes.

[0085] Example 6

[0086] The tin oxide-based thin film prepared in this embodiment has a composition of Li. 0.03 Sn 0.97 O 1.9 F 0.1 .

[0087] The method for preparing the tin oxide-based thin film in this embodiment is as follows:

[0088] (1) A tin oxide-based thin film was deposited using a magnetron sputtering device. The target material for magnetron sputtering was La-doped tin oxide ceramic. The substrate was placed in the reaction chamber of the magnetron sputtering device, the reaction chamber was evacuated, and the temperature of the substrate was controlled at 180°C.

[0089] (2) Argon and oxygen are introduced into the reaction chamber to make the gas pressure in the reaction chamber 0.4 Pa, and the power of magnetron sputtering is controlled to be 1.48 W / cm. 2 Tin oxide-based thin films were deposited for 27 minutes.

[0090] Example 7

[0091] The tin oxide-based thin film prepared in this embodiment has a composition of Li. 0.01 Zn 0.01 Sn 0.98 O.

[0092] The method for preparing the tin oxide-based thin film in this embodiment is as follows:

[0093] (1) A tin oxide-based thin film was deposited using a magnetron sputtering device. The target material for magnetron sputtering was tin oxide ceramic co-doped with Li and Zn. The substrate was placed in the reaction chamber of the magnetron sputtering device, the reaction chamber was evacuated, and the temperature of the substrate was controlled at 180°C.

[0094] (2) Argon and oxygen are introduced into the reaction chamber to make the gas pressure in the reaction chamber 0.4 Pa, and the power of magnetron sputtering is controlled to be 1.48 W / cm. 2 Tin oxide-based thin films were deposited for 27 minutes.

[0095] Comparative Example 1

[0096] The tin oxide-based thin film prepared in this comparative example has a composition of Li. 0.12 Sn 0.88 O.

[0097] The method for preparing the tin oxide-based thin film in this comparative example is as follows:

[0098] (1) A tin oxide-based thin film was deposited using a magnetron sputtering device. The target material for magnetron sputtering was Li-doped tin oxide ceramic. The substrate was placed in the reaction chamber of the magnetron sputtering device, the reaction chamber was evacuated, and the temperature of the substrate was controlled at 400°C.

[0099] (2) Argon and oxygen are introduced into the reaction chamber to make the gas pressure in the reaction chamber 0.4 Pa, and the power of magnetron sputtering is controlled to be 1.48 W / cm. 2 Tin oxide-based thin films were deposited for 27 minutes.

[0100] Comparative Example 2

[0101] The tin oxide-based thin film prepared in this comparative example has a composition of Mg. 0.05 Sn 0.95 O.

[0102] The method for preparing the tin oxide-based thin film in this comparative example is as follows:

[0103] (1) A tin oxide-based thin film was deposited using a magnetron sputtering device. The target material for magnetron sputtering was Mg-doped tin oxide ceramic. The substrate was placed in the reaction chamber of the magnetron sputtering device, the reaction chamber was evacuated, and the temperature of the substrate was controlled at 400°C.

[0104] (2) Argon and oxygen are introduced into the reaction chamber to make the gas pressure in the reaction chamber 0.4 Pa, and the power of magnetron sputtering is controlled to be 1.48 W / cm. 2 Tin oxide-based thin films were deposited for 27 minutes.

[0105] Comparative Example 3

[0106] The tin oxide-based thin film prepared in this comparative example has a composition of Zn. 0.08 Sn 0.92 O.

[0107] The method for preparing the tin oxide-based thin film in this comparative example is as follows:

[0108] (1) A tin oxide-based thin film was deposited using a magnetron sputtering device. The target material for magnetron sputtering was Zn-doped tin oxide ceramic. The substrate was placed in the reaction chamber of the magnetron sputtering device, the reaction chamber was evacuated, and the temperature of the substrate was controlled at 400°C.

[0109] (2) Argon and oxygen are introduced into the reaction chamber to make the gas pressure in the reaction chamber 0.4 Pa, and the power of magnetron sputtering is controlled to be 1.48 W / cm. 2 Tin oxide-based thin films were deposited for 27 minutes.

[0110] Comparative Example 4

[0111] The tin oxide-based thin film prepared in this comparative example has the following composition: Y 0.03 Sn 0.97 O.

[0112] The method for preparing the tin oxide-based thin film in this comparative example is as follows:

[0113] (1) A tin oxide-based thin film was deposited using a magnetron sputtering device. The target material for magnetron sputtering was Y-doped tin oxide ceramic. The substrate was placed in the reaction chamber of the magnetron sputtering device, the reaction chamber was evacuated, and the temperature of the substrate was controlled at 600°C.

[0114] (2) Argon and oxygen are introduced into the reaction chamber to make the gas pressure in the reaction chamber 0.4 Pa, and the power of magnetron sputtering is controlled to be 1.48 W / cm. 2 Tin oxide-based thin films were deposited for 27 minutes.

[0115] Comparative Example 5

[0116] The tin oxide-based thin film prepared in this comparative example has a composition of La. 0.04 Sn 0.96 O.

[0117] The method for preparing the tin oxide-based thin film in this comparative example is as follows:

[0118] (1) A tin oxide-based thin film was deposited using a magnetron sputtering device. The target material for magnetron sputtering was La-doped tin oxide ceramic. The substrate was placed in the reaction chamber of the magnetron sputtering device, the reaction chamber was evacuated, and the temperature of the substrate was controlled at 500°C.

[0119] (2) Argon and oxygen are introduced into the reaction chamber to make the gas pressure in the reaction chamber 0.4 Pa, and the power of magnetron sputtering is controlled to be 1.48 W / cm. 2 Tin oxide-based thin films were deposited for 27 minutes.

[0120] Comparative Example 6

[0121] The tin oxide-based thin film prepared in this comparative example has the following composition: Ba 0.1 Sn 0.9 O, where Ba 2+ The radius is 135 pm.

[0122] The method for preparing the tin oxide-based thin film in this comparative example is as follows:

[0123] (1) A tin oxide-based thin film was deposited using a magnetron sputtering device. The target material for magnetron sputtering was Ba-doped tin oxide ceramic. The substrate was placed in the reaction chamber of the magnetron sputtering device, the reaction chamber was evacuated, and the temperature of the substrate was controlled at 180°C.

[0124] (2) Argon and oxygen are introduced into the reaction chamber to make the gas pressure in the reaction chamber 0.4 Pa, and the power of magnetron sputtering is controlled to be 1.48 W / cm. 2 Tin oxide-based thin films were deposited for 27 minutes.

[0125] The compositions of the tin oxide-based thin films prepared in Examples 1-7 and Comparative Examples 1-6, as well as the temperature, pressure, power, and time of magnetron sputtering in the preparation process, are shown in Table 1 below:

[0126] Table 1

[0127]

[0128] Reference Figures 1-6 The electrical properties of the tin oxide-based thin films prepared in Examples 1-7 and Comparative Examples 1-6 were tested. Figures 1-6 The images show the XRD patterns of the tin oxide-based thin films prepared in Examples 1-5, 7 and Comparative Examples 1-5. These include the carrier concentration n (10⁻⁶). 20 / cm 3 ), mobility μ (cm) 2 / Vs), resistivity ρ (10 -3 Ωcm), and also tested the transmittance T (%) and absorbance A (%), referring to Figures 7-12 Furthermore, the tin oxide-based thin films prepared in Examples 1-4 and 7, as well as the SnO-based thin films, were also analyzed. 0.98 F 0.02 The work function of the tin oxide-based thin film was tested. Figures 7-12 The UPS diagrams for the above-mentioned tin oxide-based thin films are shown in Table 2 below.

[0129] Table 2

[0130]

[0131] As shown in Table 2 above, the tin oxide-based thin films prepared in Examples 1-7 all exhibit higher carrier concentration (n), higher mobility (μ), significantly lower resistivity, higher transmittance (T), and lower absorbance (A) compared to the tin oxide-based thin films prepared in Comparative Examples 1-6. In Examples 1-6, the deposition temperature was controlled at 180℃, i.e., within the range of 20℃ to 300℃, which resulted in amorphous tin oxide-based thin films. In contrast, the deposition temperatures in Comparative Examples 1-6 were all above 400℃, leading to the crystallization of the tin oxide-based thin films. This indicates that when the dopant element M is a dopant metal element with an ionic radius less than or equal to 120 pm, and the tin oxide-based thin film material is amorphous, a tin oxide-based thin film with better electrical properties can be obtained.

[0132] Meanwhile, the component is SnO 0.98 F 0.02 The tin oxide-based thin film, used as a control group, had a work function of 3.66 eV. The tin oxide-based thin film prepared in Example 1 had a composition of Li. 0.12 Sn 0.88 The work function of the tin oxide film prepared in Examples 2-4 is 3.58 eV, which is lower than that of the control group film. This means that when M is Li and y=0, a tin oxide-based film with a reduced work function can be obtained. The work functions of the films prepared in Examples 7-8 are higher than those of the control group film. This means that when M is at least Mg, Zn, or Y, a tin oxide-based film with an increased work function can be obtained. 0.01 Zn 0.01 Sn 0.98 O, where M includes Li and Zn, has a work function of 3.71 eV. In this application, the work function of the tin oxide-based thin film can be tuned by doping with different elements, thus broadening its applicability in solar cells and flexible devices.

[0133] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0134] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims, and the specification and drawings can be used to interpret the content of the claims.

Claims

1. A tin oxide-based thin film, characterized in that, This includes materials with amorphous structures having the following general chemical formula: M x Sn 1-x O 2(1-y) F 2y Wherein, 0.001≤x≤0.2, y=0, M is a doped metal element with an ionic radius less than or equal to 120 pm; M includes one or more of Li and Zn, Mg, Ca, Y and La, and the work function of the tin oxide-based thin film is greater than 3.4 eV and less than 4.5 eV.

2. The tin oxide-based thin film according to claim 1, characterized in that, M is Li and y=0, and the work function of the tin oxide-based thin film is greater than 3.4 eV and less than 3.66 eV.

3. The tin oxide-based thin film according to claim 1, characterized in that, M is one or more of Zn, Mg, Ca, Y and La, and the work function of the tin oxide-based thin film is greater than 3.66 eV and less than 4.5 eV.

4. The tin oxide-based thin film according to any one of claims 1 to 3, characterized in that, The thickness of the tin oxide-based thin film is 1 nm to 200 nm.

5. A method for preparing a tin oxide-based thin film according to any one of claims 1 to 4, characterized in that, include: A tin oxide-based thin film is prepared on a substrate, the tin oxide-based thin film comprising a material having an amorphous structure with the following general chemical formula: M x Sn 1-x O 2(1-y) F 2y Wherein, 0.001≤x≤0.2, y=0, M is a doped metal element with an ionic radius less than or equal to 120 pm; M includes one or more of Li and Zn, Mg, Ca, Y and La, and the work function of the tin oxide-based thin film is greater than 3.4 eV and less than 4.5 eV; The preparation of a tin oxide-based thin film on a substrate includes: depositing the tin oxide-based thin film using a tin oxide target containing a doped metal element M; the deposition temperature is 20°C to 300°C.

6. The method for preparing tin oxide-based thin films according to claim 5, characterized in that, The deposition time is 2 min to 100 min; And / or, the deposition power is 0.2 W / cm². 2 ~3W / cm 2 .

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