Transparent conductive oxide thin film, perovskite solar cell and preparation method of transparent conductive oxide thin film and perovskite solar cell

Abstract

The invention relates to the technical field of solar cells, in particular to a transparent conductive oxide thin film, a perovskite solar cell and a preparation method of the transparent conductive oxide thin film. The transparent conductive oxide thin film includes a tellurium-doped transparent conductive oxide. According to the embodiment of the invention, tellurium is used as a doping element, and when doping is carried out in the transparent conductive oxide, the tellurium element can enter lattice vacancies and fill vacancy defects or gap defects, so that the carrier mobility, the carrier concentration, the sheet resistance and the resistivity of the TCO thin film are improved, and the performance of the perovskite solar cell is improved.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a transparent conductive oxide film and a perovskite solar cell and a preparation method thereof. Background Art

[0002] Transparent conductive oxide (TCO) film is a thin film material with good light transmittance and conductivity. It is widely used in touch screens, liquid crystal displays, organic light emitting diodes, thin film solar cells and other fields, and has broad application prospects.

[0003] Common TCO films include indium tin oxide (ITO), fluorine-doped tin oxide (FTO), indium zinc oxide (IZO), indium / zinc co-doped indium oxide (IZTO), etc. ITO film and FTO film both have high visible light transmittance (~90%), low square resistance (~10Ω / square), good chemical stability and process repeatability, and are widely used as bottom and top electrodes of perovskite solar cells. For semi-transparent perovskite solar cells, TCO film plays a vital role in the photoelectric performance and stability of the cell.

[0004] However, the relatively low carrier concentration and conductivity of TCO thin films limit their application in perovskite solar cells to a certain extent. In particular, when TCO thin films are deposited on the surface of perovskite solar cell substrates by magnetron sputtering, a large number of collisions of accelerated high-energy particles such as negative oxygen ions, secondary electrons and neutral particles in the plasma will seriously damage the perovskite light-absorbing layer, resulting in a significant attenuation of the efficiency and photoelectric performance of perovskite solar cells. In order to solve the problem of sputtering damage, a buffer layer can be deposited on the surface of the cell substrate by atomic layer deposition or vacuum evaporation before preparing the transparent electrode to alleviate the damage of high-energy sputtering particles to the perovskite light-absorbing layer. However, this method has limited effect on the improvement of the carrier concentration and conductivity of the TCO thin film, which in turn affects the photoelectric conversion efficiency and stability of perovskite solar cells.

[0005] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the invention

[0006] The embodiments of the present application provide a transparent conductive oxide film and a perovskite solar cell and a preparation method thereof to improve the carrier concentration and conductivity of the TCO film.

[0007] A first aspect of an embodiment of the present application provides a transparent conductive oxide (TCO) film.

[0008] According to an embodiment of the present application, the transparent conductive oxide thin film includes tellurium-doped transparent conductive oxide.

[0009] In the embodiments of the present application, tellurium (Te) is used as a doping element. When doping is performed in a transparent conductive oxide, the tellurium element can enter the lattice vacancies and fill in the vacancy defects or interstitial defects, thereby improving the carrier mobility, carrier concentration, square resistance and resistivity of the TCO film.

[0010] A second aspect provides a method for preparing a transparent conductive oxide film.

[0011] According to an embodiment of the present application, the method for preparing the transparent conductive oxide film comprises the following operations: magnetron sputtering is performed using a tellurium target and a transparent conductive oxide target to form the transparent conductive oxide film described in the first aspect. Thus, a transparent conductive oxide film with a precisely controllable thickness and doping ratio can be obtained.

[0012] According to another embodiment of the present application, the method for preparing the transparent conductive oxide film comprises the following operations: magnetron sputtering is performed using a tellurium-doped transparent conductive oxide target to form the transparent conductive oxide film described in the first aspect. Thus, a transparent conductive oxide film with a precisely controllable thickness and doping ratio can be obtained.

[0013] A third aspect of the embodiments of the present application provides a perovskite solar cell.

[0014] According to an embodiment of the present application, the perovskite solar cell includes the transparent conductive oxide film described in the first aspect. Thus, a transparent conductive oxide film with significantly improved carrier concentration and conductivity is used to improve the conversion efficiency of the perovskite solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0016] Figure 1 It is a schematic diagram of the structure of a perovskite solar cell provided in an embodiment of the present application.

[0017] Description of reference numerals: 100-bottom electrode; 200-hole transport layer; 300-perovskite light absorption layer; 400-passivation layer; 500-electron transport layer; 600-buffer layer; 700-transparent conductive oxide film. DETAILED DESCRIPTION

[0018] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, for clarity, the sizes of layers, regions, elements and their relative sizes may be exaggerated. Wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limitations on the present application. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0019] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. When the second element, component, region, layer or part is discussed, it does not indicate that the present application necessarily has the first element, component, region, layer or part.

[0020] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0021] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0022] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows for broadly including quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0023] The following provides an explanation of the terms used in this application.

[0024] DMF is N,N-dimethylformamide; ITO is indium tin oxide; IZO is zinc-doped indium oxide; AZO is aluminum-doped zinc oxide; FTO is fluorine-doped tin oxide; IWO is tungsten-doped indium oxide; 2PACZ is [2-(9H-carbazole-9-yl)ethyl]phosphonic acid.

[0025] The embodiments of the present application provide a transparent conductive oxide film and a perovskite solar cell and a method for preparing the same. Based on this, the problem of low carrier concentration and conductivity of the TCO film is solved. See below for details.

[0026] Hereinafter, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments can be implemented in many different forms and should not be construed as being limited to the embodiments described herein.

[0027] A first aspect of the embodiments of the present application provides a transparent conductive oxide (TCO) film.

[0028] In some embodiments, the transparent conductive oxide thin film includes a tellurium-doped transparent conductive oxide.

[0029] In the embodiment of the present application, tellurium (Te) is used as a doping element. Since tellurium is a semi-metallic element, it has the properties of metal and non-metal. In addition, tellurium also has high carrier mobility, high absorption coefficient, high quantum yield and low diffusion rate, which can improve the photoelectric performance of transparent conductive oxide films. Specifically, when doping in transparent conductive oxides, tellurium elements can enter lattice vacancies and fill in vacancy defects or interstitial defects, thereby improving the carrier mobility, carrier concentration, square resistance and resistivity of the TCO film.

[0030] In some embodiments, in the transparent conductive oxide film, based on the mass of the transparent conductive oxide, the doping amount of the tellurium element in the transparent conductive oxide film is 0.1wt% to 2wt%. For example, the doping amount of the tellurium element can be 0.1wt%, 0.15wt%, 0.18wt%, 2wt%, etc. Therefore, when the doping amount of tellurium is in the range of 0.1wt% to 2wt%, tellurium enters the lattice of the TCO film and fills the interstitial defects and vacancy defects in the TCO film. At the same time, as the doping amount of tellurium increases, the band gap of the TCO film will increase, which is more conducive to the transmission and extraction of electrons. However, when the doping amount of tellurium is greater than 2wt%, the photoelectric properties of the TCO film will be changed, seriously affecting the carrier mobility and square resistance of the TCO film, which is not conducive to the transmission and extraction of carriers, resulting in a significant decrease in the efficiency of perovskite solar cells.

[0031] In some embodiments, the thickness of the transparent conductive oxide film is 50 nm to 500 nm, for example, the thickness of the transparent conductive oxide film can be 50 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 400 nm, 500 nm, etc. Therefore, when used as the top electrode of the perovskite solar cell, it is beneficial to light absorption and the transmission and collection of the generated charges.

[0032] The embodiments of the present application do not limit the types of transparent conductive oxides, and those skilled in the art can select them according to their needs. For example, the transparent conductive oxide film also includes at least one of indium tin oxide, fluorine-doped tin oxide, indium zinc oxide, and indium zinc co-doped indium oxide.

[0033] A second aspect of the embodiments of the present application provides a method for preparing a transparent conductive oxide film.

[0034] In some embodiments, the method for preparing the transparent conductive oxide film comprises the following operations: magnetron sputtering is performed using a tellurium target and a transparent conductive oxide target to form the transparent conductive oxide film described in the first aspect, thereby obtaining a transparent conductive oxide film with a precisely controllable thickness and doping ratio.

[0035] In other embodiments, the method for preparing the transparent conductive oxide film includes the following operations: magnetron sputtering is performed using a tellurium-doped transparent conductive oxide target to form the transparent conductive oxide film described in the first aspect, thereby obtaining a transparent conductive oxide film with a precisely controllable thickness and doping ratio.

[0036] A third aspect of the embodiments of the present application provides a perovskite solar cell.

[0037] In some embodiments, the perovskite solar cell comprises the transparent conductive oxide film described in the first aspect. Thus, a transparent conductive oxide film with significantly improved carrier concentration and conductivity is used to improve the conversion efficiency of the perovskite solar cell.

[0038] Optionally, the perovskite solar cell may be one of a formal perovskite solar cell, an inverted perovskite solar cell, a perovskite-silicon two-terminal tandem cell and a perovskite-silicon four-terminal tandem cell.

[0039] Preferably, the band gap of the perovskite light absorbing layer of the perovskite solar cell is 1.52eV to 1.56eV. Thus, the band gap perovskite light absorbing layer can improve the photoelectric performance of the TCO film by adjusting the doping amount of tellurium in the TCO film, thereby significantly improving the open circuit voltage (Voc), fill factor (FF), short circuit current (Jsc) and photoelectric conversion efficiency (PCE) of the perovskite solar cell. The more obvious change is that when the band gap of the top TCO film is more matched with the band gap of the bottom battery, the Voc of the battery will be significantly improved. At the same time, when the TCO film has a higher carrier mobility and a lower square resistance, the FF and Jsc of the battery will also be significantly improved.

[0040] Optionally, the perovskite light-absorbing layer comprises ABX3 type perovskite; wherein A is one or more of methylamine, formamidine, acetamidine, cesium or rubidium; B is one or more of lead, tin, copper and germanium; X is F - ,I - Br - , Cl - , BF 4- PF 6- and SCN - One or more of .

[0041] Furthermore, the perovskite light absorbing layer can be prepared by spin coating, blade coating, spray coating and / or slit coating of a perovskite precursor solution.

[0042] Optionally, the perovskite precursor solution can be prepared in the following manner: obtain metal halide and organic ammonium halide according to the chemical formula of the perovskite light absorbing layer; dissolve the metal halide and organic ammonium halide in an organic solvent; wherein the perovskite light absorbing layer includes ABX3, wherein A is a monovalent cation formed by one or more of methylamine, formamidine, acetamidine, cesium and rubidium; B is a divalent cation formed by one or more of lead, tin, copper and germanium; X is F - ,I - Br - , Cl - , BF 4- PF 6- and SCN - One or more of .

[0043] Optionally, in the perovskite precursor solution, the concentration of divalent metal ions is 200 mg / mL to 600 mg / mL.

[0044] Optionally, the organic solvent includes at least one of dimethyl sulfoxide, N,N-dimethylformamide, acetonitrile, dimethylpyrrolidone, 2-methoxyethanol, and γ-butyrolactone.

[0045] Optionally, the perovskite solar cell further includes an electron transport layer, a hole transport layer and an electrode; wherein the transparent conductive oxide film, the electron transport layer, the perovskite light absorbing layer, the hole transport layer and the electrode are stacked.

[0046] Furthermore, the materials of the electron transport layer include [6,6]-phenyl-C71-butyric acid isomethyl ester (PCBM), SnO2, TiO2, ZnO2, Al2O3, C 60 and indene-C 60 One or more of the bisadducts (ICBA).

[0047] Furthermore, the materials of the hole transport layer include organic hole transport materials, inorganic hole transport materials, self-assembled monolayer materials (Self-Assembled Monolayer, referred to as SAMs), etc.

[0048] Furthermore, the materials of SAMs include [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACZ), (2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl)phosphonic acid (MeO-2PACZ), (4-(3,6-dimethyl-9H-carbazole-9-yl)ethyl)phosphonic acid (Me-4PACZ), (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanotitanyl)phosphonic acid (MPA-CPA) and (4-(2,7-dibromo-9,9-dimethylacridin-10(9H)yl)butyl)phosphonic acid (DMAcPA), poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) and NiO x One or more of .

[0049] Preferably, a buffer layer is provided between the transparent conductive oxide film and the electron transport layer, thereby alleviating the damage of the perovskite light absorption layer caused by high-energy sputtering particles when the transparent conductive oxide film is prepared by magnetron sputtering.

[0050] Optionally, the buffer layer may be a molybdenum oxide film and / or a tin oxide film.

[0051] Optionally, the buffer layer has a thickness of 10 nm to 50 nm.

[0052] A fourth aspect of the embodiments of the present application provides a method for preparing a perovskite solar cell.

[0053] In some embodiments, the method for preparing the perovskite solar cell comprises the following operations: A perovskite solar cell substrate is provided, wherein the perovskite solar cell substrate comprises a bottom electrode, a hole transport layer, a perovskite light absorption layer and an electron transport layer stacked in sequence; Using the side where the electron transport layer is located as the sputtering surface, magnetron sputtering is performed, and a tellurium target and a transparent conductive oxide target are used to simultaneously perform the first stage of sputtering until a transparent conductive oxide film with a first preset target thickness is formed; Performing a second stage of sputtering simultaneously with a tellurium target and a transparent conductive oxide until a transparent conductive oxide film having a second preset target thickness is formed; Wherein, the sputtering power of the tellurium target in the second stage of sputtering is greater than the sputtering power of the tellurium target in the first stage of sputtering; The sputtering power of the transparent conductive oxide target in the second stage of sputtering is greater than the sputtering power of the transparent conductive oxide target in the first stage of sputtering.

[0054] In the embodiment of the present application, dual targets are used for magnetron sputtering, and the power of the two targets is controlled separately to achieve quantitative doping, and sputtering is performed in stages, first using low power for sputtering to form a transparent electrode film with a first preset target thickness, and then using high power for sputtering to complete sputtering. In this way, the damage to the perovskite light absorption layer during the magnetron sputtering process can be effectively reduced.

[0055] Preferably, the sputtering power of the tellurium target in the first stage of sputtering is 5W to 20W, and the sputtering power of the transparent conductive oxide target in the first stage of sputtering is 10W to 50W. Thus, the tellurium and transparent conductive oxide contents are controlled by separately setting the sputtering power, and low power is used for sputtering to avoid damage to the perovskite light absorbing layer.

[0056] Preferably, the sputtering power of the tellurium target in the second stage of sputtering is 20 W to 50 W, and the sputtering power of the transparent conductive oxide target in the second stage of sputtering is 40 W to 250 W. Thus, by controlling the tellurium and transparent conductive oxide contents by setting the sputtering power separately and using high power for sputtering at the same time, a transparent conductive oxide film can be formed quickly.

[0057] In the embodiment of the present application, the reaction chamber of the magnetron sputtering apparatus needs to be evacuated before sputtering, and argon gas is introduced into the reaction chamber, and argon gas is continuously introduced during the sputtering process. Optionally, the argon gas flow rate is 10sccm to 50sccm, and the reaction chamber pressure is 0.1Pa to 1.0Pa. Optionally, the temperature of the reaction chamber is room temperature, and the target diameter is 10cm to 20cm.

[0058] In some other embodiments, the method for preparing the perovskite solar cell comprises the following operations: A perovskite solar cell substrate is provided, wherein the perovskite solar cell substrate comprises a bottom electrode, a hole transport layer, a perovskite light absorption layer and an electron transport layer stacked in sequence; Using the side where the electron transport layer is located as the sputtering surface, magnetron sputtering is performed, and a tellurium-doped transparent conductive oxide target is used for the first stage of sputtering until a transparent conductive oxide film with a first preset target thickness is formed; Using the tellurium-doped transparent conductive oxide target to perform second-stage sputtering until a transparent conductive oxide film with a second preset target thickness is formed; The sputtering power of the tellurium-doped transparent conductive oxide target in the second stage of sputtering is greater than the sputtering power in the first stage of sputtering.

[0059] In the embodiment of the present application, a single target is used for magnetron sputtering, and the power of the two targets is controlled to achieve quantitative doping, and sputtering is performed in stages, first using low power for sputtering to form a transparent electrode film with a first preset target thickness, and then using high power for sputtering to complete sputtering. In this way, the damage to the perovskite light absorption layer during the magnetron sputtering process can be effectively reduced.

[0060] It can be understood that the tellurium content in the tellurium-doped transparent conductive oxide is fixed. Based on the mass of the transparent conductive oxide, the doping amount of the tellurium element can be 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.8wt%, 1wt%, 1.5wt%, 1.8wt%, 2wt%, etc.

[0061] Preferably, the sputtering power of the first stage sputtering is 10W-50W, and the sputtering power of the second stage sputtering is 50W-250W.

[0062] Optionally, the first preset target thickness is 5 nm to 20 nm.

[0063] Optionally, the second preset target thickness is 50 nm to 500 nm.

[0064] In some embodiments, in the method for preparing the perovskite solar cell, the perovskite solar cell substrate further comprises a buffer layer, and the buffer layer is stacked on a side of the electron transport layer away from the perovskite light absorbing layer; during sputtering, magnetron sputtering is performed with the side where the buffer layer is located as the sputtering surface. Thus, by introducing the buffer layer, the damage to the perovskite light absorbing layer can be further reduced.

[0065] The embodiments of the present application also provide a perovskite solar cell prepared by the fourth aspect of the present application.

[0066] In some embodiments, see Figure 1 The perovskite solar cell includes a bottom electrode 100, a hole transport layer 200, a perovskite light absorption layer 300, a passivation layer 400, an electron transport layer 500, a buffer layer 600 and a transparent conductive oxide film 700 which are stacked in sequence.

[0067] The following will conduct performance tests on the preparation method of the perovskite solar cell provided in the embodiments of the present application and related comparative examples.

[0068] [Example 1] The specific preparation process is: Step 1: Prepare the perovskite solar cell substrate (101) With the chemical formula Cs 0.05 FA 0.90 MA 0.05Taking PbI3 as the target, weigh FAI, PbI2, MACl, MAI, and CsI powders and mix them, add 1 mL of solvent (DMF:NMP=5:1) to dissolve them, and obtain a perovskite precursor solution; (102) 2PACZ was dissolved in IPA solution to prepare a hole transport solution with a concentration of 1 mg / mL; (103) Clean the FTO glass and blow dry it with nitrogen; The hole transport solution was coated on the FTO glass by a slit coating method, and an annealing treatment was performed to remove the solvent. The temperature of the annealing treatment was 100° C. and the time was 10 min.

[0069] (104) The perovskite precursor solution was prepared on the hole transport layer using a slit coating method and an annealing treatment was performed to remove the solvent. The annealing temperature was 130 °C and the time was 30 min.

[0070] Among them, the band gap of the perovskite light-absorbing layer is 1.56eV.

[0071] (105) A 30 nm thick C layer was deposited on the perovskite light absorbing layer by vacuum thermal evaporation. 60 , as an electron transport layer; (106) Atomic layer deposition was used to deposit 60 A 20 nm SnO2 film was prepared on the surface as a buffer layer to obtain a perovskite solar cell substrate.

[0072] Step 2: Use a mask to cover the non-electrode area of ​​the perovskite solar cell substrate, place it in the reaction chamber of the magnetron sputtering instrument, and evacuate the reaction chamber to a vacuum degree of 3×10 -4 Pa; continuously introduce argon gas into the reaction chamber and maintain the gas flow rate at 20 sccm; after the argon gas flow rate stabilizes, increase the pressure of the chamber to 0.1 Pa; after the pressure of the reaction chamber stabilizes, adjust the distance between the perovskite solar cell substrate and the tellurium target to 25 cm, and the distance between the perovskite solar cell substrate and the ITO target to 20 cm.

[0073] The co-sputtering process was carried out in stages: in the first stage, the sputtering power of the tellurium target was adjusted to 30 W, the sputtering power of the ITO target was adjusted to 50 W, and the sputtering time was 20 min to obtain a 30 nm thick tellurium-doped ITO composite film; in the second stage, the sputtering power of the tellurium target was adjusted to 50 W, the sputtering power of the ITO target was adjusted to 120 W, and the sputtering time was 30 min to obtain a 0.6 wt% tellurium-doped ITO composite film with a thickness of 300 nm, which is the top electrode of the perovskite solar cell.

[0074] [Example 2] Step 1 is the same as step 1 of Example 1, except that: Step 2: The co-sputtering process is carried out in stages: in the first stage, the sputtering power of the tellurium target is adjusted to 40 W, the sputtering power of the ITO target is adjusted to 50 W, and the sputtering time is 15 minutes to obtain a 30 nm thick tellurium-doped ITO composite film; in the second stage, the sputtering power of the tellurium target is adjusted to 70 W, the sputtering power of the ITO target is adjusted to 120 W, and the sputtering time is 25 minutes to obtain a 1.0 wt% tellurium-doped ITO composite film with a thickness of 300 nm, which is the top electrode of the perovskite solar cell.

[0075] [Example 3] Step 1 is the same as step 1 of Example 1, except that: Step 2: The co-sputtering process is carried out in stages: in the first stage, the sputtering power of the tellurium target is adjusted to 20 W, the sputtering power of the ITO target is adjusted to 50 W, and the sputtering time is 30 min to obtain a 30 nm thick tellurium-doped ITO composite film; in the second stage, the sputtering power of the tellurium target is adjusted to 40 W, the sputtering power of the ITO target is adjusted to 120 W, and the sputtering time is 40 min to obtain a 0.5 wt% tellurium-doped ITO composite film with a thickness of 300 nm, which is the top electrode of the perovskite solar cell.

[0076] [Example 4] Step 1 is the same as step 1 of Example 1, except that: In step 2, the ITO target is replaced with an IZO target.

[0077] The non-electrode area of ​​the perovskite solar cell substrate was shielded by a mask, placed in the reaction chamber of the magnetron sputtering instrument, and the vacuum degree of the reaction chamber was pumped to 3×10 -4 Pa; then, argon gas is continuously introduced into the reaction chamber, and the gas flow rate is maintained at 20 sccm; after the argon gas flow rate is stabilized, the pressure of the chamber is increased to 0.1 Pa; after the pressure of the reaction chamber is stabilized, the distance between the perovskite solar cell substrate and the tellurium target is adjusted to 25 cm, and the distance between the perovskite solar cell substrate and the IZO target is adjusted to 20 cm.

[0078] The co-sputtering process was carried out in stages: in the first stage, the sputtering power of the tellurium target was adjusted to 40 W, the sputtering power of the IZO target was adjusted to 50 W, and the sputtering time was 15 min to obtain a 30 nm thick tellurium-doped IZO composite film; in the second stage, the sputtering power of the tellurium target was adjusted to 70 W, the sputtering power of the IZO target was adjusted to 120 W, and the sputtering time was 30 min to obtain a 1.2 wt% tellurium-doped IZO composite film with a thickness of 300 nm, which is the top electrode of the perovskite solar cell.

[0079] [Example 5] Step 1: Same as step 1 of Example 1.

[0080] The non-electrode area of ​​the perovskite solar cell substrate was shielded by a mask, placed in the reaction chamber of the magnetron sputtering instrument, and the vacuum degree of the reaction chamber was pumped to 3×10 -4 Pa; argon gas is continuously introduced into the reaction chamber, and the gas flow rate is maintained at 20 sccm; after the argon gas flow rate is stabilized, the pressure of the chamber is increased to 0.1 Pa.

[0081] After the pressure in the reaction chamber is stabilized, the distance between the perovskite solar cell substrate and the target is adjusted to 20 cm; among them, a tellurium-doped ITO target is used with a doping amount of 0.3 wt%.

[0082] The co-sputtering process was carried out in stages: in the first stage, the sputtering power was 30 W, the sputtering time was 20 min, and a tellurium-doped ITO composite film with a thickness of about 30 nm was obtained; in the second stage, the sputtering power was increased to 120 W, the sputtering time was 30 min, and a tellurium-doped ITO composite film with a thickness of about 300 nm was obtained, which was the top electrode of the perovskite solar cell.

[0083] [Example 6] The rest is the same as Example 5, except that the target material used is a tellurium-doped ITO target with a doping amount of 0.6 wt %.

[0084] [Example 7] The rest is the same as Example 5, except that the target material used is a tellurium-doped ITO target with a doping amount of 1 wt %.

[0085] [Example 8] The rest is the same as Example 5, except that the target material used is a tellurium-doped IZO target with a doping amount of 0.6 wt %.

[0086] [Example 9] The rest is the same as Example 5, except that the target material used is a tellurium-doped ITO target with a doping amount of 2.5 wt %.

[0087] [Example 10] The rest is the same as Example 1, except that: The band gap of the (104) perovskite light absorbing layer prepared in step 1 is 1.58 eV, and the perovskite light absorbing layer is Cs 0.17 FA 0.83 PbI3. [Example 11] The rest is the same as Example 1, except that: The band gap of the (104) perovskite light absorbing layer prepared in step 1 is 1.54 eV, and the perovskite light absorbing layer is FA0.92 Cs 0.08 PbI3.

[0088] [Example 12] The rest is the same as Example 1, except that: The band gap of the (104) perovskite light absorbing layer prepared in step 1 is 1.52 eV, and the perovskite light absorbing layer is FA 0.95 Cs 0.05 PbI3.

[0089] [Example 13] The rest is the same as Example 1, except that: The band gap of the (104) perovskite light absorbing layer prepared in step 1 is 1.47 eV, and the perovskite light absorbing layer is FAPbI3.

[0090] [Comparative Example 1] The rest is the same as Example 5, except that: The target material used is ITO target.

[0091] [Comparative Example 2] The rest is the same as Example 5, except that: The target material used is IZO target.

[0092]

Test example

[0093] The perovskite solar cells of Examples 1 to 13 and Comparative Examples 1 to 2 were subjected to IV tests at 100 mW / cm 2 IV tests were carried out under AM1.5G lighting conditions to obtain open circuit voltage (Voc), short circuit current (Jsc), fill factor (FF) and photoelectric conversion efficiency (PCE) data, as shown in Table 3.

[0094] The variables of Examples 1 to 13 and Comparative Examples 1 to 2 are shown in Table 1.

[0095] Table 1:

[0096] Table 2

[0097] It can be found from the Hall test results in Table 2 that Examples 1, 2 and 4 have lower square resistance and higher carrier mobility than Comparative Examples 1 and 2, which indicates that the addition of tellurium into the transparent conductive oxide film can optimize the square resistance and carrier mobility; in addition, Examples 4 and 9 indicate that excessive tellurium doping will significantly increase the square resistance of the TCO film and significantly reduce the carrier mobility, which will seriously hinder the transport and extraction of carriers in the perovskite solar cell.

[0098] Table 3

[0099] It can be seen from Table 3 that in the perovskite solar cell with a band gap of 1.56eV, when the TCO electrode is prepared by the co-sputtering process of tellurium target and ITO target, the cell efficiency first increases and then decreases with the increase of tellurium doping amount, but it is higher than the efficiency of the cell prepared by ITO single target sputtering. The change in cell efficiency is mainly due to the increase in cell opening voltage and filling factor. When the tellurium doping amount is 1.0wt%, the cell efficiency reaches a maximum of 21.70% and the opening voltage is 1.14V. When the TCO electrode is prepared by the co-sputtering process of tellurium target and IZO target, the cell efficiency reaches a maximum of 19.31% and the opening voltage is 1.09V. In the tellurium-ITO single target co-sputtering, the cell efficiency also shows a trend of increasing first and then decreasing with the increase of tellurium doping amount. The change in efficiency is mainly due to the increase of cell opening voltage and filling factor. When the tellurium doping amount is 0.6wt%, the cell efficiency reaches a maximum of 20.09%, the opening voltage is 1.10V, and the filling factor is 83.24%. In particular, when the tellurium doping amount is 2.5wt%, the photoelectric performance of the cell is significantly reduced, the cell efficiency is 15.84%, and the opening voltage is 1.05V. The reduction in cell efficiency is mainly due to the deterioration of TCO film performance. In addition, in order to verify the effect of the TCO film on the performance of perovskites with different band gaps, this application compares the perovskite light absorbing layers of 1.47eV~1.58eV. When the TCO electrode is prepared by the co-sputtering process of tellurium target and ITO target (doping amount is 0.6wt%), the 1.54eV perovskite light absorbing layer has the best performance, the cell efficiency reaches 19.52%, and the opening voltage is 1.11V. The performance of the cells with the 1.58eV and 1.47eV perovskite light absorbing layers is poor, which is because the band gap of the perovskite light absorbing layer does not match the band gap of the TCO, resulting in a significant reduction in the opening voltage and fill factor of the cell. In summary, in the magnetron sputtering method, the process of using tellurium-doped TCO thin film to prepare the transparent electrode of perovskite solar cell can effectively improve the performance of TCO thin film within the doping range of 0.1wt% to 2wt% by adjusting the doping amount of tellurium in the TCO thin film, that is, reduce the square resistance of the TCO thin film, improve the carrier mobility of the TCO thin film, and thus significantly improve the photoelectric conversion efficiency of the perovskite solar cell. At the same time, by changing the doping amount of tellurium in the TCO thin film, the transparent electrode prepared can better match the perovskite light absorption layer with different band gaps (preferably 1.52eV to 1.56eV), thereby significantly improving the open circuit voltage and photoelectric conversion efficiency of the battery.

[0100] It should be noted that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The orientation words "inside" and "outside" refer to the inside and outside relative to the outline of each component itself. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, the exemplary term "above..." can include both "above..." and "below..." orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here are interpreted accordingly.

[0101] It should also be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this application refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0102] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0103] It should also be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A transparent conductive oxide film, characterized in that: Includes tellurium-doped transparent conductive oxides.

2. The transparent conductive oxide thin film according to claim 1, characterized in that: Based on the mass of the transparent conductive oxide, the doping amount of the tellurium element in the transparent conductive oxide film is 0.1wt% to 2wt%.

3. The transparent conductive oxide film according to claim 1, characterized in that: The thickness of the transparent conductive oxide film is 50nm-500nm.

4. The transparent conductive oxide film according to claim 1, characterized in that: The transparent conductive oxide film further comprises at least one of indium tin oxide, fluorine-doped tin oxide, indium zinc oxide, and indium zinc co-doped indium oxide.

5. A method for preparing a transparent conductive oxide film, characterized in that: The following operations are included: Using a tellurium target and a transparent conductive oxide target together for magnetron sputtering to form the transparent conductive oxide thin film according to any one of claims 1 to 4; or A tellurium-doped transparent conductive oxide target is used for magnetron sputtering to form the transparent conductive oxide film according to any one of claims 1 to 4.

6. A perovskite solar cell, characterized in that: The transparent conductive oxide film comprises the transparent conductive oxide film according to any one of claims 1 to 4.

7. The perovskite solar cell according to claim 6, characterized in that: It also includes a perovskite light-absorbing layer; Wherein, the band gap of the perovskite light absorbing layer is 1.47eV to 1.65eV.

8. The perovskite solar cell according to claim 7, characterized in that: The perovskite light absorbing layer includes ABX3 type perovskite; Wherein, A is one or more of methylamine, formamidine, acetamidine, cesium or rubidium; B is one or more of lead, tin, copper and germanium; X is F - ,I - Br - , Cl - , BF 4- PF 6- and SCN - One or more of .

9. The perovskite solar cell according to claim 7, characterized in that: The perovskite solar cell also includes an electron transport layer, a hole transport layer and an electrode; Wherein, the transparent conductive oxide film, the electron transport layer, the perovskite light absorption layer, the hole transport layer and the electrode are stacked.

10. A method for preparing a perovskite solar cell, characterized in that: The following operations are included: A perovskite solar cell substrate is provided, wherein the perovskite solar cell substrate comprises a bottom electrode, a hole transport layer, a perovskite light absorption layer and an electron transport layer stacked in sequence; Using the side where the electron transport layer is located as the sputtering surface, magnetron sputtering is performed, and a tellurium target and a transparent conductive oxide target are used to simultaneously perform the first stage of sputtering until a transparent conductive oxide film with a first preset target thickness is formed; Performing a second stage of sputtering simultaneously with a tellurium target and a transparent conductive oxide until a transparent conductive oxide film having a second preset target thickness is formed; The sputtering power of the tellurium target in the second stage of sputtering is greater than that of the tellurium target in the first stage of sputtering; the sputtering power of the transparent conductive oxide target in the second stage of sputtering is greater than that of the transparent conductive oxide target in the first stage of sputtering.

11. The method for preparing a perovskite solar cell according to claim 10, characterized in that: The sputtering power of the tellurium target in the first stage of sputtering is 5W to 20W, and the sputtering power of the transparent conductive oxide target in the first stage of sputtering is 10W to 50W; and / or The sputtering power of the tellurium target in the second stage of sputtering is 20W-50W, and the sputtering power of the transparent conductive oxide target in the second stage of sputtering is 40W-250W.

12. A method for preparing a perovskite solar cell, characterized in that: The following operations are included: A perovskite solar cell substrate is provided, wherein the perovskite solar cell substrate comprises a bottom electrode, a hole transport layer, a perovskite light absorption layer and an electron transport layer stacked in sequence; Using the side where the electron transport layer is located as the sputtering surface, magnetron sputtering is performed, and a tellurium-doped transparent conductive oxide target is used for the first stage of sputtering until a transparent conductive oxide film with a first preset target thickness is formed; Using the tellurium-doped transparent conductive oxide target to perform second-stage sputtering until a transparent conductive oxide film with a second preset target thickness is formed; The sputtering power of the tellurium-doped transparent conductive oxide target in the second stage of sputtering is greater than the sputtering power in the first stage of sputtering.

13. The method for preparing a perovskite solar cell according to claim 12, characterized in that: The sputtering power of the first stage sputtering is 10W-50W, and the sputtering power of the second stage sputtering is 50W-250W.

14. The method for preparing a perovskite solar cell according to claim 12 or 13, characterized in that: The first preset target thickness is 5nm to 20nm; The second preset target thickness is 50 nm to 500 nm.

15. The method for preparing a perovskite solar cell according to claim 12 or 13, characterized in that: The perovskite solar cell substrate further comprises a buffer layer, which is stacked on a side of the electron transport layer away from the perovskite light absorbing layer; During sputtering, magnetron sputtering is performed with the side where the buffer layer is located as the sputtering surface.

16. A perovskite solar cell, characterized in that: Prepared according to the preparation method according to any one of claims 10 to 15.

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