Transparent conductive oxide thin films and perovskite solar cells and methods of making the same

Abstract

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

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and in particular to a transparent conductive oxide thin film and a perovskite solar cell and a method for preparing the same. Background Technology

[0002] Transparent conductive oxide (TCO) films are thin film materials with good light transmittance and conductivity. They are widely used in touch screens, liquid crystal displays, organic light-emitting diodes, and thin-film solar cells, and have broad application prospects.

[0003] Common TCO thin films include indium tin oxide (ITO), fluorine-doped tin oxide (FTO), indium zinc oxide (IZO), and indium / zinc co-doped indium oxide (IZTO). ITO and FTO films both possess high visible light transmittance (~90%), low sheet resistance (~10 Ω / square), good chemical stability, and process repeatability, and are widely used as the bottom and top electrodes of perovskite solar cells. For semi-transparent perovskite solar cells, TCO thin films play a crucial 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 some extent. In particular, when depositing TCO thin films on the surface of perovskite solar cell substrates via magnetron sputtering, the numerous collisions of accelerated high-energy particles such as negative oxygen ions, secondary electrons, and neutral particles from the plasma severely damage the perovskite light-absorbing layer, leading to a significant decrease in the efficiency and photoelectric performance of the perovskite solar cell. To address the sputtering damage problem, a buffer layer can be deposited on the surface of the cell substrate before fabricating the transparent electrode using atomic layer deposition or vacuum evaporation to mitigate the damage to the perovskite light-absorbing layer caused by high-energy sputtering particles. However, this method has limited effect on improving the carrier concentration and conductivity of the TCO thin film, thus affecting the photoelectric conversion efficiency and stability of the perovskite solar cell.

[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] This application provides a transparent conductive oxide thin film and a perovskite solar cell, and a method for preparing the same, to improve the carrier concentration and conductivity of the TCO thin film.

[0007] The first aspect of this application provides a transparent conductive oxide (TCO) thin film.

[0008] According to an embodiment of this application, the transparent conductive oxide film comprises tellurium-doped transparent conductive oxide.

[0009] In this embodiment, tellurium (Te) is used as a dopant element. When doping a transparent conductive oxide, the tellurium element can enter the lattice vacancies and fill the vacancy defects or interstitial defects, thereby improving the carrier mobility, carrier concentration, sheet resistance and resistivity of the TCO thin film.

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

[0011] According to embodiments of this application, the method for preparing the transparent conductive oxide thin film includes the following operations: magnetron sputtering using a tellurium target and a transparent conductive oxide target to form the transparent conductive oxide thin film described in the first aspect. This yields a transparent conductive oxide thin film with precisely controllable thickness and doping ratio.

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

[0013] A third aspect of this application provides a perovskite solar cell.

[0014] According to an embodiment of this application, the perovskite solar cell includes the transparent conductive oxide thin film described in the first aspect. Therefore, by employing a transparent conductive oxide thin film with significantly improved carrier concentration and conductivity, the conversion efficiency of the perovskite solar cell is improved. Attached Figure Description

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

[0016] Figure 1 This is a schematic diagram of the structure of the perovskite solar cell provided in the embodiments of this application.

[0017] Explanation of reference numerals in the attached figures:

[0018] 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 Implementation

[0019] The embodiments of this application are described in detail below, examples of which are illustrated in the accompanying drawings. In the drawings, for clarity, the dimensions of layers, regions, and elements, as well as their relative dimensions, may be exaggerated. Throughout, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0020] 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 may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this application, the first element, component, area, layer, or portion discussed below may be referred to as a second element, component, area, layer, or portion. And the discussion of a second element, component, area, layer, or portion does not imply that the first element, component, area, layer, or portion necessarily exists in this application.

[0021] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0023] In this application, when numerical intervals (i.e., numerical ranges) are involved, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every 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 ranges disclosed in this application should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include percentage intervals, ratio intervals, proportion intervals, etc.

[0024] The following provides a definition of the terminology used in this application.

[0025] DMF stands for N,N-dimethylformamide; ITO stands for indium tin oxide; IZO stands for zinc-doped indium oxide; AZO stands for aluminum-doped zinc oxide; FTO stands for fluorine-doped tin oxide; IWO stands for tungsten-doped indium oxide; and 2PACZ stands for [2-(9H-carbazole-9-yl)ethyl]phosphonic acid.

[0026] This application provides a transparent conductive oxide thin film and a perovskite solar cell, as well as a method for fabricating the same. Based on this, the problems of low carrier concentration and conductivity in TCO thin films are solved. Details are provided below.

[0027] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. It should be understood that these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein.

[0028] The first aspect of this application provides a transparent conductive oxide (TCO) thin film.

[0029] In some embodiments, the transparent conductive oxide film comprises tellurium-doped transparent conductive oxide.

[0030] In this embodiment, tellurium (Te) is used as the dopant element. Since tellurium is a half-metal, it possesses both metallic and non-metallic properties. Furthermore, tellurium exhibits high carrier mobility, high absorption coefficient, high quantum yield, and low diffusion rate, which can improve the photoelectric properties of transparent conductive oxide thin films. Specifically, when doping transparent conductive oxides, tellurium can enter lattice vacancies and fill vacancy defects or interstitial defects, thereby improving the carrier mobility, carrier concentration, sheet resistance, and resistivity of the TCO thin film.

[0031] In some embodiments, the tellurium doping amount in the transparent conductive oxide thin film is 0.1 wt% to 2 wt%, based on the mass of the transparent conductive oxide. For example, the tellurium doping amount can be 0.1 wt%, 0.15 wt%, 0.18 wt%, 2 wt%, etc. Thus, when the tellurium doping amount is in the range of 0.1 wt% to 2 wt%, tellurium enters the crystal lattice of the TCO thin film, filling interstitial and vacancy defects. Simultaneously, increasing the tellurium doping amount leads to an increase in the band gap of the TCO thin film, which is more conducive to electron transport and extraction. However, when the tellurium doping amount is greater than 2 wt%, it alters the photoelectric properties of the TCO thin film, severely affecting the carrier mobility and sheet resistance, thereby hindering carrier transport and extraction, resulting in a significant decrease in the efficiency of perovskite solar cells.

[0032] 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 a perovskite solar cell, it is beneficial for both light absorption and the transport and collection of generated charges.

[0033] This application does not limit the type of transparent conductive oxide, and those skilled in the art can select it according to their needs. Exemplarily, the transparent conductive oxide film further includes at least one of indium tin oxide, fluorine-doped tin oxide, indium zinc oxide, and indium zinc co-doped indium oxide.

[0034] The second aspect of this application provides a method for preparing a transparent conductive oxide thin film.

[0035] In some embodiments, the method for preparing the transparent conductive oxide thin film includes the following steps: magnetron sputtering using a tellurium target and a transparent conductive oxide target to form the transparent conductive oxide thin film described in the first aspect. This yields a transparent conductive oxide thin film with precisely controllable thickness and doping ratio.

[0036] In other embodiments, the method for preparing the transparent conductive oxide thin film includes the following steps: magnetron sputtering using a tellurium-doped transparent conductive oxide target to form the transparent conductive oxide thin film described in the first aspect. This allows for the obtaining of a transparent conductive oxide thin film with precisely controllable thickness and doping ratio.

[0037] A third aspect of this application provides a perovskite solar cell.

[0038] In some embodiments, the perovskite solar cell includes the transparent conductive oxide film described in the first aspect. Thus, by employing a transparent conductive oxide film with significantly improved carrier concentration and conductivity, the conversion efficiency of the perovskite solar cell is improved.

[0039] Optionally, the perovskite solar cell can be one of the following: a conventional perovskite solar cell, an inverted perovskite solar cell, a perovskite-silicon two-terminal tandem cell, and a perovskite-silicon four-terminal tandem cell.

[0040] Preferably, the band gap of the perovskite light-absorbing layer in the perovskite solar cell is 1.52 eV to 1.56 eV. Therefore, by adjusting the tellurium doping amount in the TCO film, the photoelectric performance of the TCO film can be improved, thereby significantly increasing the open-circuit voltage (Voc), fill factor (FF), short-circuit current (Jsc), and power conversion efficiency (PCE) of the perovskite solar cell. A particularly noticeable change is that when the band gaps of the top TCO film and the bottom cell are well matched, the Voc of the cell is significantly improved. Simultaneously, when the TCO film has high carrier mobility and low sheet resistance, the FF and Jsc of the cell are also significantly improved.

[0041] Optionally, the perovskite light-absorbing layer comprises ABX3 type perovskite; wherein A is one or more of methylamine, formamidinium, acetamidine, cesium, or rubidium; B is one or more of lead, tin, copper, and germanium; and X is F - I - ,Br - Cl - BF 4- PF 6- and SCN - One or more of them.

[0042] Furthermore, the perovskite light-absorbing layer can be prepared from a perovskite precursor solution by spin coating, blade coating, spray coating, and / or slot coating.

[0043] Optionally, the perovskite precursor solution can be prepared by: obtaining metal halides and organic ammonium salt halides according to the chemical formula of the perovskite light-absorbing layer; dissolving the metal halides and organic ammonium salt halides in an organic solvent; wherein the perovskite light-absorbing layer comprises ABX3, where A is a monovalent cation formed from one or more of methylamine, formamidinium, acetamidine, cesium, and rubidium; B is a divalent cation formed from one or more of lead, tin, copper, and germanium; and X is F - I - ,Br - Cl - BF 4- PF 6- and SCN - One or more of them.

[0044] Optionally, the concentration of divalent metal ions in the perovskite precursor solution is 200 mg / mL to 600 mg / mL.

[0045] Optionally, the organic solvent includes at least one of dimethyl sulfoxide, N,N-dimethylformamide, acetonitrile, dimethylpyrrolidone, 2-methoxyethanol, and γ-butyrolactone.

[0046] Optionally, the perovskite solar cell further includes an electron transport layer, a hole transport layer, and electrodes; wherein the transparent conductive oxide film, the electron transport layer, the perovskite light-absorbing layer, the hole transport layer, and the electrodes are stacked.

[0047] Furthermore, the materials for the electron transport layer include isomethyl [6,6]-phenyl-C71-butyrate (PCBM), SnO2, TiO2, ZnO2, Al2O3, and C. 60 and indene-C 60 One or more of the diadducts (ICBAs).

[0048] Furthermore, the materials for hole transport layers include organic hole transport materials, inorganic hole transport materials, and self-assembled monolayers (SAMs).

[0049] 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):polystyrene sulfonate (PEDOT:PSS), and NiO x One or more of them.

[0050] Preferably, a buffer layer is provided between the transparent conductive oxide thin film and the electron transport layer. This helps to mitigate the damage to the perovskite light-absorbing layer caused by high-energy sputtering particles during the fabrication of the transparent conductive oxide thin film using magnetron sputtering.

[0051] Optionally, the buffer layer may be a molybdenum oxide film and / or a tin oxide film.

[0052] Optionally, the thickness of the buffer layer is 10 nm to 50 nm.

[0053] The fourth aspect of this application provides a method for fabricating a perovskite solar cell.

[0054] In some embodiments, the method for fabricating the perovskite solar cell includes the following operations:

[0055] A perovskite solar cell substrate is provided, the perovskite solar cell substrate comprising a bottom electrode, a hole transport layer, a perovskite light-absorbing layer and an electron transport layer stacked sequentially;

[0056] Magnetron sputtering is performed on the side where the electron transport layer is located, and the first stage sputtering is performed simultaneously using a tellurium target and a transparent conductive oxide target until a transparent conductive oxide film with a first preset target thickness is formed.

[0057] The second stage of sputtering is performed simultaneously using a tellurium target and a transparent conductive oxide until a transparent conductive oxide film of a second preset target thickness is formed;

[0058] In the second stage of sputtering, the sputtering power of the tellurium target is greater than that of the tellurium target in the first stage of sputtering.

[0059] The sputtering power of the transparent conductive oxide target in the second stage sputtering is greater than that in the first stage sputtering.

[0060] In this embodiment, magnetron sputtering is performed using dual targets. The power of the two targets is controlled separately to achieve quantitative doping. Sputtering is performed in stages: first, low-power sputtering is used to form a transparent electrode film with a first preset target thickness; then, high-power sputtering is used to complete the sputtering process. This effectively reduces damage to the perovskite light-absorbing layer during magnetron sputtering.

[0061] 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 content of tellurium and transparent conductive oxide is controlled by individually setting the sputtering power, while using low power for sputtering to avoid damage to the perovskite light-absorbing layer.

[0062] Preferably, the sputtering power of the tellurium target in the second stage sputtering is 20W to 50W, and the sputtering power of the transparent conductive oxide target in the second stage sputtering is 40W to 250W. Thus, by controlling the tellurium and transparent conductive oxide content through separate sputtering power settings, and simultaneously using high-power sputtering, a transparent conductive oxide thin film can be rapidly formed.

[0063] In this embodiment, the reaction chamber of the magnetron sputtering instrument needs to be evacuated before sputtering, and argon gas is introduced into the reaction chamber. Argon gas is continuously introduced during the sputtering process. Optionally, the argon gas flow rate is 10 sccm to 50 sccm, and the reaction chamber pressure is 0.1 Pa to 1.0 Pa. Optionally, the temperature of the reaction chamber is room temperature, and the target diameter is 10 cm to 20 cm.

[0064] In other embodiments, the method for fabricating this perovskite solar cell includes the following operations:

[0065] A perovskite solar cell substrate is provided, the perovskite solar cell substrate comprising a bottom electrode, a hole transport layer, a perovskite light-absorbing layer and an electron transport layer stacked sequentially;

[0066] Magnetron sputtering is performed on the side where the electron transport layer is located as the sputtering surface, 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.

[0067] The second stage of sputtering is performed using the tellurium-doped transparent conductive oxide target until a transparent conductive oxide film of the second preset target thickness is formed;

[0068] In the second stage of sputtering, the sputtering power of the tellurium-doped transparent conductive oxide target is greater than that in the first stage of sputtering.

[0069] In this embodiment, magnetron sputtering is performed using a single target, and the power of the two targets is controlled to achieve quantitative doping. Sputtering is performed in stages: first, low-power sputtering is used to form a transparent electrode film with a first preset target thickness; then, high-power sputtering is used to complete the sputtering process. This effectively reduces damage to the perovskite light-absorbing layer during magnetron sputtering.

[0070] It is 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 tellurium can be 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.8wt%, 1wt%, 1.5wt%, 1.8wt%, 2wt%, etc.

[0071] Preferably, the sputtering power of the first stage sputtering is 10W to 50W, and the sputtering power of the second stage sputtering is 50W to 250W.

[0072] Optionally, the first preset target thickness is 5nm to 20nm.

[0073] Optionally, the second preset target thickness is 50 nm to 500 nm.

[0074] In some embodiments, in the fabrication method of this perovskite solar cell, the perovskite solar cell substrate further includes a buffer layer, which is stacked on the side of the electron transport layer away from the perovskite light-absorbing layer; during sputtering, magnetron sputtering is performed with the side containing the buffer layer as the sputtering surface. Thus, by introducing the buffer layer, damage to the perovskite light-absorbing layer can be further mitigated.

[0075] This application also provides perovskite solar cells prepared according to the fourth aspect of this application.

[0076] In some embodiments, see Figure 1 The perovskite solar cell comprises 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 thin film 700, which are stacked sequentially.

[0077] The following section will present performance tests on the fabrication method of the perovskite solar cell provided in the embodiments of this application, as well as related comparative examples.

[0078]

Example 1

[0079] The specific preparation process is as follows:

[0080] Step 1: Fabrication of perovskite solar cell substrate

[0081] (101) with the chemical formula Cs0.05 FA 0.90 MA 0.05 Using PbI3 as the target, FAI, PbI2, MACl, MAI, and CsI powders were weighed and mixed, and 1 mL of solvent (DMF:NMP=5:1) was added to dissolve them to obtain a perovskite precursor solution.

[0082] (102) Dissolve 2PACZ in IPA solution to prepare a hole transport solution with a concentration of 1 mg / mL;

[0083] (103) Clean the FTO glass and dry it with nitrogen;

[0084] Hole transport solution was coated onto FTO glass using a slot coating method, followed by a first annealing treatment to remove the solvent. The first annealing treatment was performed at a temperature of 100℃ for 10 minutes.

[0085] (104) A perovskite light-absorbing layer was prepared on the hole transport layer by using the slit coating method to prepare the perovskite precursor solution and then subjected to a first annealing treatment to remove the solvent. The annealing temperature was 130℃ and the time was 30min.

[0086] The perovskite light-absorbing layer has a band gap of 1.56 eV.

[0087] (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;

[0088] (106) Atomic layer deposition method is used in C 60 A 20 nm SnO2 thin film was prepared on the surface as a buffer layer to obtain a perovskite solar cell substrate.

[0089] Step 2: Use a mask to shield the non-electrode areas of the perovskite solar cell substrate, place it in the reaction chamber of the magnetron sputtering machine, and evacuate the reaction chamber to a vacuum level of 3 × 10⁻⁶. -4 Pa; Argon gas is continuously introduced into the reaction chamber at a flow rate of 20 sccm; After the argon gas flow rate stabilizes, the pressure in the chamber is increased to 0.1 Pa; After the pressure in the reaction chamber stabilizes, 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 ITO target is adjusted to 20 cm.

[0090] A staged co-sputtering process was adopted: In the first stage, the sputtering power of the tellurium target was adjusted to 30W, the sputtering power of the ITO target was adjusted to 50W, and the sputtering time was 20min, resulting in a 30nm thick tellurium-doped ITO composite film; In the second stage, the sputtering power of the tellurium target was adjusted to 50W, the sputtering power of the ITO target was adjusted to 120W, and the sputtering time was 30min, resulting in a 300nm thick 0.6wt% tellurium-doped ITO composite film, which is the top electrode of the perovskite solar cell.

[0091]

Example 2

[0092] Step 1 is the same as step 1 in Example 1, except that:

[0093] Step 2: A staged co-sputtering process is adopted: In the first stage, the sputtering power of the tellurium target is adjusted to 40W, the sputtering power of the ITO target is adjusted to 50W, and the sputtering time is 15min, to obtain a 30nm thick tellurium-doped ITO composite film; In the second stage, the sputtering power of the tellurium target is adjusted to 70W, the sputtering power of the ITO target is adjusted to 120W, and the sputtering time is 25min, to obtain a 300nm thick 1.0wt% tellurium-doped ITO composite film, which is the top electrode of the perovskite solar cell.

[0094]

Example 3

[0095] Step 1 is the same as step 1 in Example 1, except that:

[0096] Step 2: A staged co-sputtering process is adopted: In the first stage, the sputtering power of the tellurium target is adjusted to 20W, the sputtering power of the ITO target is adjusted to 50W, and the sputtering time is 30min, resulting in a 30nm thick tellurium-doped ITO composite film; In the second stage, the sputtering power of the tellurium target is adjusted to 40W, the sputtering power of the ITO target is adjusted to 120W, and the sputtering time is 40min, resulting in a 300nm thick 0.5wt% tellurium-doped ITO composite film, which is the top electrode of the perovskite solar cell.

[0097]

Example 4

[0098] Step 1 is the same as step 1 in Example 1, except that:

[0099] In step 2, the ITO target is replaced with an IZO target.

[0100] The non-electrode areas of the perovskite solar cell substrate were shielded using a mask and placed into the reaction chamber of a magnetron sputtering machine, with the vacuum level of the reaction chamber evacuated to 3 × 10⁻⁶. -4Pa; 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 stabilizes, the pressure of the chamber is increased to 0.1 Pa; after the pressure of the reaction chamber stabilizes, 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.

[0101] A staged co-sputtering process was adopted: In the first stage, the sputtering power of the tellurium target was adjusted to 40W, the sputtering power of the IZO target was adjusted to 50W, and the sputtering time was 15min, resulting in a 30nm thick tellurium-doped IZO composite film; In the second stage, the sputtering power of the tellurium target was adjusted to 70W, the sputtering power of the IZO target was adjusted to 120W, and the sputtering time was 30min, resulting in a 300nm thick 1.2wt% tellurium-doped IZO composite film, which is the top electrode of the perovskite solar cell.

[0102]

Example 5

[0103] Step 1: Same as Step 1 in Example 1.

[0104] The non-electrode areas of the perovskite solar cell substrate were shielded using a mask and placed into the reaction chamber of a magnetron sputtering machine, with the vacuum level of the reaction chamber evacuated to 3 × 10⁻⁶. -4 Pa; Argon gas is continuously introduced into the reaction chamber at a flow rate of 20 sccm; After the argon gas flow rate stabilizes, the pressure in the chamber is increased to 0.1 Pa.

[0105] After the pressure in the reaction chamber stabilizes, the distance between the perovskite solar cell substrate and the target is adjusted to 20 cm; among them, tellurium-doped ITO target material is used with a doping amount of 0.3 wt%.

[0106] The co-sputtering process was carried out in stages: in the first stage, the sputtering power was 30W and the sputtering time was 20min, resulting in a tellurium-doped ITO composite film with a thickness of about 30nm; in the second stage, the sputtering power was increased to 120W and the sputtering time was 30min, resulting in a tellurium-doped ITO composite film with a thickness of about 300nm, which is the top electrode of the perovskite solar cell.

[0107]

Example 6

[0108] Everything else is the same as in Example 5, except that the target material used is a tellurium-doped ITO target with a doping amount of 0.6 wt%.

[0109]

Example 7

[0110] Everything else is the same as in Example 5, except that the target material used is a tellurium-doped ITO target with a doping amount of 1 wt%.

[0111]

Example 8

[0112] Everything else is the same as in Example 5, except that the target material used is a tellurium-doped IZO target with a doping amount of 0.6 wt%.

[0113]

Example 9

[0114] Everything else is the same as in Example 5, except that the target material used is a tellurium-doped ITO target with a doping amount of 2.5 wt%.

[0115]

Example 10

[0116] Everything else is the same as in Example 1, except that:

[0117] The (104) perovskite absorbing layer prepared in step 1 has a band gap of 1.58 eV, and the perovskite absorbing layer is Cs. 0.17 FA 0.83 PbI3.

[0118]

Example 11

[0119] Everything else is the same as in Example 1, except that:

[0120] The (104) perovskite absorbing layer prepared in step 1 has a band gap of 1.54 eV, and the perovskite absorbing layer is FA. 0.92 Cs 0.08 PbI3.

[0121]

Example 12

[0122] Everything else is the same as in Example 1, except that:

[0123] The (104) perovskite absorbing layer prepared in step 1 has a band gap of 1.52 eV, and the perovskite absorbing layer is FA. 0.95 Cs 0.05 PbI3.

[0124]

Example 13

[0125] Everything else is the same as in Example 1, except that:

[0126] The (104) perovskite light-absorbing layer prepared in step 1 has a band gap of 1.47 eV and is FAPbI3.

[0127] Comparative Example 1

[0128] Everything else is the same as in Example 5, except that:

[0129] The target material used is an ITO target.

[0130] Comparative Example 2

[0131] Everything else is the same as in Example 5, except that:

[0132] The target material used is an IZO target.

[0133] [Test Example]

[0134] Sheet resistance and Hall effect performance of the TCO single films (approximately 300 nm) from Examples 1, 2, 4, 9, and Comparative Examples 1-2 were tested, with a test area of ​​1 cm². 2 The sheet resistance, carrier mobility, carrier concentration, and resistivity of the thin film were obtained and are shown in Table 2.

[0135] IV tests were performed on the perovskite solar cells of Examples 1-13 and Comparative Examples 1-2 at 100 mW / cm². 2 IV tests were conducted under AM1.5G illumination to obtain open-circuit voltage (Voc), short-circuit current (Jsc), fill factor (FF), and photoelectric conversion efficiency (PCE) data, as shown in Table 3.

[0136] The variables for Examples 1-13 and Comparative Examples 1-2 are shown in Table 1.

[0137] Table 1:

[0138]

[0139] Table 2

[0140]

[0141] The Hall effect test results in Table 2 show that Examples 1, 2, and 4 have lower sheet resistance and higher carrier mobility compared to Comparative Examples 1 and 2. This indicates that doping tellurium into the transparent conductive oxide film can optimize sheet resistance and carrier mobility. In addition, Examples 4 and 9 show that excessively high tellurium doping levels will significantly increase the sheet 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.

[0142] Table 3

[0143]

[0144] Table 3 shows that in perovskite solar cells with a bandgap of 1.56 eV, when using a co-sputtering process with tellurium and ITO targets to prepare TCO electrodes, the cell efficiency first increases and then decreases with increasing tellurium doping concentration, but remains higher than that of cells prepared by ITO single-target sputtering. The change in cell efficiency is mainly due to the improvement in cell turn-on voltage and fill factor. When the tellurium doping concentration is 1.0 wt%, the cell efficiency reaches a maximum of 21.70%, with a turn-on voltage of 1.14 V. When using a co-sputtering process with tellurium and IZO targets to prepare TCO electrodes, the cell efficiency reaches a maximum of 19.31%, with a turn-on voltage of 1.09 V. In tellurium-ITO single-target co-sputtering, the cell efficiency initially increases and then decreases with increasing tellurium doping concentration. This efficiency variation primarily stems from improvements in the cell's on-state voltage and fill factor. The highest efficiency (20.09%) is achieved with a tellurium doping concentration of 0.6 wt%, an on-state voltage of 1.10 V, and a fill factor of 83.24%. Notably, when the tellurium doping concentration reaches 2.5 wt%, the photoelectric performance of the cell significantly decreases, with an efficiency of 15.84% and an on-state voltage of 1.05 V. This decrease in efficiency is mainly due to the deterioration of the TCO thin film performance. Furthermore, to verify the effect of the TCO film on the performance of perovskites with different band gaps, this application compared perovskite absorber layers with band gaps ranging from 1.47 eV to 1.58 eV. When the TCO electrode was fabricated using a co-sputtering process with tellurium and ITO targets (doping amount of 0.6 wt%), the perovskite absorber layer with a band gap of 1.54 eV exhibited the best performance, achieving a cell efficiency of 19.52% and an on-state voltage of 1.11 V. The cell performance of the perovskite absorber layers with band gaps of 1.58 eV and 1.47 eV was poor. This is because the band gap of the perovskite absorber layer did not match the band gap of the TCO, resulting in a significant reduction in the on-state voltage and fill factor of the cell. In summary, the tellurium-doped TCO thin film process for fabricating transparent electrodes for perovskite solar cells using magnetron sputtering effectively improves the performance of the TCO thin film by adjusting the tellurium doping amount within the range of 0.1 wt% to 2 wt%. This includes reducing the sheet resistance and increasing the carrier mobility, thereby significantly enhancing the photoelectric conversion efficiency of the perovskite solar cell. Furthermore, by varying the tellurium doping amount in the TCO thin film, the prepared transparent electrode can better match perovskite light-absorbing layers with different band gaps (preferably 1.52 eV to 1.56 eV), thus significantly improving the open-circuit voltage and photoelectric conversion efficiency of the cell.

[0145] It should be noted that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. The directional terms "inner" and "outer" refer to the inside or outside relative to the outline of the component itself. For example, if a device in the drawings is inverted, a device described as "above" or "on top of" other devices or structures will subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0146] It should also be noted that the terms "one embodiment," "another embodiment," and "embodiment" used in this application refer to specific features, structures, or characteristics described in connection with that embodiment, which are included in at least one embodiment described in the general description of this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in connection with any embodiment, the intention is to suggest that implementing such a feature, structure, or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0147] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0148] It should also be noted that the above are merely preferred embodiments of this application and do not limit the scope of patent protection of this application. Any equivalent structural or procedural changes made using the content of this application’s specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A perovskite solar cell, characterized by, The transparent conductive oxide film and the perovskite light-absorbing layer are included. The band gap of the perovskite light-absorbing layer is 1.52 eV to 1.56 eV. The transparent conductive oxide film includes tellurium-doped transparent conductive oxide, and the doping amount of tellurium is 0.5 wt% to 1.2 wt% based on the mass of the transparent conductive oxide.

2. The perovskite solar cell according to claim 1, characterized in that, The transparent conductive oxide film further includes at least one of indium tin oxide, fluorine-doped tin oxide, indium zinc oxide, and indium zinc co-doped indium oxide. 3.The perovskite solar cell of claim 1, wherein, The perovskite light-absorbing layer includes an 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 one or more of F - , I - , Br - , Cl - , BF 4- , PF 6- , and SCN - . 4.The perovskite solar cell of claim 1, wherein, The perovskite solar cell further includes an electron transport layer, a hole transport layer, and an electrode. The transparent conductive oxide film, the electron transport layer, the perovskite light-absorbing layer, the hole transport layer, and the electrode are stacked.

5. A method for preparing a perovskite solar cell, characterized by, The following operations are included: A perovskite solar cell substrate is provided, which includes a bottom electrode, a hole transport layer, a perovskite light-absorbing layer, and an electron transport layer stacked in sequence. Magnetron sputtering is performed with the side where the electron transport layer is located as a sputtering surface, a tellurium target and a transparent conductive oxide target are used to perform first-stage sputtering simultaneously until a transparent conductive oxide film with a first preset target thickness is formed. Second-stage sputtering is performed using the tellurium target and the transparent conductive oxide target until a transparent conductive oxide film with a second preset target thickness is formed. In the second-stage sputtering, the sputtering power of the tellurium target is greater than that in the first-stage sputtering, and the sputtering power of the transparent conductive oxide target in the second-stage sputtering is greater than that in the first-stage sputtering. 6.The method of claim 5, wherein the perovskite solar cell is prepared by the steps of: The sputtering power of the tellurium target in the first-stage sputtering is 5 W to 20 W, and the sputtering power of the transparent conductive oxide target in the first-stage sputtering is 10 W to 50 W; and / or The sputtering power of the tellurium target in the second-stage sputtering is 20 W to 50 W, and the sputtering power of the transparent conductive oxide target in the second-stage sputtering is 40 W to 250 W.

7. A method of manufacturing a perovskite solar cell, characterized by, The following operations are included: A perovskite solar cell substrate is provided, which includes a bottom electrode, a hole transport layer, a perovskite light-absorbing layer, and an electron transport layer stacked in sequence. Magnetron sputtering is performed with the side where the electron transport layer is located as a sputtering surface, a tellurium-doped transparent conductive oxide target is used to perform first-stage sputtering until a transparent conductive oxide film with a first preset target thickness is formed. Second-stage sputtering is performed using the tellurium-doped transparent conductive oxide target until a transparent conductive oxide film with a second preset target thickness is formed. In the second-stage sputtering, the sputtering power of the tellurium-doped transparent conductive oxide target is greater than that in the first-stage sputtering.

8. The method for preparing a perovskite solar cell according to claim 7, characterized in that, The sputtering power of the first-stage sputtering is 10 W to 50 W, and the sputtering power of the second-stage sputtering is 50 W to 250 W.

9. The method for preparing a perovskite solar cell according to claim 7 or 8, characterized in that, The first preset target thickness is 5 nm to 20 nm. The second preset target thickness is 50 nm to 500 nm.

10. The method for preparing a perovskite solar cell according to claim 7 or 8, characterized in that, The perovskite solar cell substrate further includes a buffer layer, which is stacked on the side of the electron transport layer away from the perovskite light-absorbing layer. In sputtering, the side where the buffer layer is located is used as a sputtering surface for magnetron sputtering.

11. A perovskite solar cell, characterized by, The preparation method according to any one of claims 5-10.

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