Conductive film and preparation method and application thereof

Abstract

The invention provides a conductive film and a preparation method and application thereof. The preparation method of the conductive thin film comprises the following steps that a substrate is placed in coating equipment, vacuumizing is conducted, then a target material is arranged, gas is introduced for coating, the gas is nitrogen or mixed gas of nitrogen and oxygen, and the flow ratio of the nitrogen to the oxygen in the mixed gas is 0.1-10: 1. According to the preparation method disclosed by the invention, the film is formed under low-bombardment equipment, and the indium-based oxide film material with high mobility can be prepared at room temperature. The localization of surface charges is enhanced through nitrogen doping, and the mobility of the film layer is improved under the room-temperature process. The invention also provides a laminated perovskite solar cell and a preparation method thereof.

Description

Technical Field

[0001] The invention belongs to the technical field of solar cells, and in particular relates to a conductive film and a preparation method and application thereof. Background Art

[0002] With the rapid development of the photovoltaic industry, stacked perovskite solar cells have gradually become a research hotspot for the new generation of solar cells due to their high efficiency, low cost and good photoelectric conversion performance. Compared with traditional silicon-based solar cells, perovskite solar cells have a wider spectral response range and higher light absorption efficiency. However, the efficiency improvement of perovskite solar cells not only depends on the performance of the perovskite material itself, but also is restricted by the performance of transparent conductive film (Transparent Conductive Oxide, TCO). Semi-transparent conductive films not only need to have excellent electrical conductivity, but also must have high light transmittance to support efficient current transmission and effective use of light, thereby promoting the improvement of photovoltaic cell efficiency. Therefore, the application requirements of transparent conductive films in stacked perovskite solar cells are getting higher and higher, becoming one of the key issues to be solved in this field.

[0003] At present, traditional transparent conductive films are usually prepared by magnetron sputtering technology. The magnetron sputtering method can prepare uniform films under controlled conditions and is widely used in the preparation of conductive films such as indium-based oxide films (such as ITO). However, the TCO films prepared by magnetron sputtering have the problems of low mobility and poor conductivity, which makes it difficult to meet the current transmission requirements of high-efficiency perovskite solar cells. In addition, during the magnetron sputtering process, the bombardment energy of the sputtering particles is large, which can easily cause damage to the underlying material of the film, especially for stacked perovskite solar cells. The bombardment of high-energy particles will damage the structure of the perovskite layer, resulting in a decrease in the photoelectric conversion efficiency. Therefore, although magnetron sputtering can prepare high-quality transparent conductive films, its negative impact on device performance during the film formation process makes it difficult to directly apply it in stacked perovskite solar cells.

[0004] In order to overcome the above problems, researchers gradually realized that in the stacked perovskite solar cells, the preparation of transparent conductive films should avoid high temperature and high energy bombardment, and a gentle and efficient process must be used. Traditional indium-based oxide films usually need to be annealed at high temperature (over 200°C) to improve the mobility of the film, but this process poses a challenge to the thermal stability of the perovskite material. Since the perovskite is formed sequentially, it is necessary to grow the hole transport layer, perovskite layer, electron transport layer, semi-transparent conductive film layer and silver electrode on the same substrate in sequence. The substrate of the semi-transparent electrode layer has grown the perovskite on the substrate and cannot be peeled off. The perovskite cannot withstand high temperatures above 150°C, which will cause the top battery layer (the stacked battery is composed of a bottom battery crystalline silicon battery and a top battery perovskite battery. The top battery here refers to the perovskite battery) to decompose, thereby affecting the overall efficiency. Therefore, how to prepare a conductive film with high mobility and no damage to the perovskite material through low-energy deposition technology under room temperature conditions needs to be solved urgently. Summary of the invention

[0005] The present invention aims to solve at least one of the above-mentioned technical problems existing in the prior art. To this end, the present invention provides a method for preparing a conductive film. By controlling the flow ratio of nitrogen and oxygen, the nitrogen doping method can adjust the electrical and optical properties of the conductive film and increase the adjustability of the film. This provides flexibility for different application fields, and the conductivity, transparency and other characteristics of the film can be adjusted according to actual needs, thereby optimizing the performance of different types of optoelectronic devices.

[0006] The invention also provides a conductive film.

[0007] The invention also provides a laminated perovskite solar cell.

[0008] The invention also provides a method for preparing a laminated perovskite solar cell.

[0009] The first aspect of the present invention provides a method for preparing a conductive film, comprising the following steps: placing a substrate in a coating device, evacuating the substrate, setting a target material, and introducing a gas for coating, wherein the gas is nitrogen or a mixture of nitrogen and oxygen, and the flow ratio of nitrogen to oxygen in the mixture is 0.1 to 10:1.

[0010] A technical solution in the method for preparing a conductive film of the present invention has at least the following beneficial effects:

[0011] The preparation method of the conductive film of the present invention forms a film under low bombardment equipment and can prepare a high-mobility indium-based oxide film material at room temperature. Nitrogen doping enhances the localization of surface charges and improves the mobility of the film layer under room temperature process.

[0012] Furthermore, the method for preparing the conductive film of the present invention can also bring the following beneficial effects:

[0013] Improve the optical properties of the film: Nitrogen doping can adjust the optical band gap of the film, making it have a higher light transmittance. For conductive films, higher light transmittance helps to use sunlight more efficiently and improve the photoelectric conversion efficiency of solar cells. Nitrogen doping can not only improve the conductivity of the film, but also reduce the absorption of visible light, improve the transparency of the film, and optimize its performance in optoelectronic applications.

[0014] Improved chemical stability of the film: Nitrogen-doped films may have higher chemical stability. The stability of the film is crucial under long-term working conditions such as solar cells. Nitrogen doping can enhance the corrosion resistance of indium-based oxides, improve the stability of the film in the environment, especially in the presence of humidity and oxygen, which can extend the service life of the film and improve the reliability of optoelectronic devices.

[0015] Reduced manufacturing costs: The conductive film preparation method is carried out under low temperature and low bombardment energy conditions, which reduces the reliance on expensive post-processing processes such as high temperature annealing. The low temperature deposition process helps reduce the demand for equipment and energy, thereby reducing manufacturing costs, which is especially important for cost control in large-scale production.

[0016] Improve the conductivity of the film: Nitrogen doping enhances the electron mobility of the film and improves the conductivity. This is particularly important for the application of conductive films in electronic devices, especially in stacked perovskite solar cells, which require conductive films to have high mobility to ensure smooth conduction of current, thereby improving the efficiency of the entire photovoltaic device.

[0017] Improve the structure and surface quality of the film: Nitrogen doping may change the microstructure of the film, making its surface smoother and reducing surface defects and unevenness. This can improve the uniformity of the film, further improve the interface matching between the film and other layers (such as the perovskite layer), reduce interface defects, reduce carrier recombination, and improve the overall efficiency of the device.

[0018] Improved adjustability and functionality: By controlling the flow ratio of nitrogen and oxygen, the nitrogen doping method can adjust the electrical and optical properties of the conductive film and increase the adjustability of the film. This provides flexibility for different application fields, and the conductivity, transparency and other properties of the film can be adjusted according to actual needs, thereby optimizing the performance of different types of optoelectronic devices.

[0019] When conductivity and electron mobility are the primary considerations, especially when light transmittance is not required (such as some high-performance electronic devices), pure nitrogen can be selected as the gas. When it is necessary to balance conductivity and light transmittance, or when higher optical properties, chemical stability, structural quality and film surface smoothness are required, a mixed gas formed by nitrogen and oxygen is a better choice, especially for applications such as solar cells and transparent electrodes. Therefore, by adjusting the ratio of nitrogen and oxygen, different solutions can be selected according to the needs of specific applications to further optimize the performance of the film.

[0020] According to some embodiments of the present invention, the coating equipment includes reactive plasma coating equipment.

[0021] According to some embodiments of the present invention, the target material includes tin oxide or indium-based oxide.

[0022] According to some embodiments of the present invention, the indium-based oxide includes at least one of indium tungsten oxide (IWO), indium zinc oxide (IZO), indium cerium oxide (ICO), indium gallium oxide, indium strontium oxide, indium copper oxide, and indium cobalt oxide.

[0023] According to some embodiments of the present invention, in the mixed gas of nitrogen and oxygen, the flow ratio of nitrogen to oxygen is 1 to 4:1.

[0024] The flow ratio of nitrogen and oxygen is in the preferred range of 1:1 to 4:1, which helps to optimize the performance of the conductive film under low-energy deposition conditions. This ratio can balance the concentration of nitrogen doping, improve the conductivity and electron mobility of the film, while maintaining high light transmittance and optical properties. It can also improve the chemical stability and structural quality of the film, reduce defects, and improve the uniformity of the film, thereby achieving higher efficiency and long-term stability in stacked perovskite solar cells.

[0025] The second aspect of the present invention provides a conductive film, which is prepared by the preparation method of the first aspect of the present invention.

[0026] The conductive film is prepared by the preparation method of the first aspect of the present invention, which has the following beneficial effects:

[0027] 1. High mobility: Nitrogen doping can optimize the electronic structure of the film and significantly improve its electron mobility, thereby enhancing the conductivity of the conductive film and ensuring more efficient current transmission. This is crucial for optoelectronic devices, especially current collection and transmission of stacked perovskite solar cells.

[0028] 2. Improve optical properties: Nitrogen doping helps to adjust the optical band gap of the film, maintain a high light transmittance, and optimize its optical properties in the visible and infrared regions. This can effectively improve the photoelectric conversion efficiency, especially in optoelectronic applications such as solar cells, and improve the utilization of sunlight.

[0029] 3. Improve chemical stability: After nitrogen is doped into the film, it helps to improve the chemical stability of the film, making it better resistant to moisture and oxygen environments. This provides higher reliability and service life for optoelectronic devices that work for a long time.

[0030] 4. Reduce film defects: Nitrogen doping can improve the microstructure of the film, reduce the defect density in the film, and improve the uniformity and surface quality of the film. This is crucial for reducing interface defects, improving carrier collection efficiency, reducing recombination losses, and enhancing the overall efficiency of the device.

[0031] 5. Low-temperature preparation: The low-energy, low-temperature deposition method of the present invention can achieve high-quality preparation of thin films at room temperature, avoiding thermal damage to perovskite solar cells that may be caused by high-temperature annealing. In particular, when the perovskite layer is more sensitive to high temperatures, it can ensure that the performance of the device is not affected.

[0032] 6. The process is simple and energy-saving: The present invention adopts low-energy deposition technology and does not require post-processing such as high-temperature annealing. It can reduce energy consumption in the preparation process, reduce production costs, and has high process feasibility and economic benefits.

[0033] According to some embodiments of the present invention, the conductive film has a thickness of 10 nm to 100 nm.

[0034] According to some embodiments of the present invention, the conductive film has a thickness of 60 nm to 80 nm.

[0035] The thickness of the conductive film is within the range of 60nm to 80nm, which can ensure good conductivity and high mobility while maintaining high transparency and appropriate optical properties. This film thickness can provide sufficient conductivity paths, optimize current transmission efficiency, and effectively control the light transmittance of the film to ensure effective use of light. In addition, this film thickness range can also ensure a flat film surface, reduce defects, improve the uniformity and structural stability of the film, and enhance the overall performance and reliability of the device.

[0036] According to some embodiments of the present invention, when the target material for preparing the conductive film is an IWO target material, the transmittance of the conductive film is ≥87%, and the mobility of the conductive film is ≥45 cm 2 / V·s, and the square resistance of the conductive film is less than 70Ω / □.

[0037] According to some embodiments of the present invention, when the target material for preparing the conductive film is an IZO target material, the transmittance of the conductive film is ≥85%, and the mobility of the conductive film is ≥60cm 2 / V·s, and the square resistance of the conductive film is less than 55Ω / □.

[0038] According to some embodiments of the present invention, when the target material for preparing the conductive film is an ICO target material, the transmittance of the conductive film is ≥78%, and the mobility of the conductive film is ≥45cm 2 / V·s, and the square resistance of the conductive film is less than 55Ω / □.

[0039] The third aspect of the present invention provides a stacked perovskite solar cell, comprising a heterojunction substrate, a hole transport layer, a perovskite layer, an electron transport layer, an electrode material layer and an electrode arranged in sequence, wherein the electrode material layer comprises a conductive film prepared by the preparation method of the first aspect of the present invention.

[0040] The conductive film of the laminated perovskite solar cell prepared by the preparation method of the first aspect of the present invention has the following significant beneficial effects:

[0041] 1. Improve the photoelectric conversion efficiency: The electrode material layer has low resistance and high mobility, which can effectively improve the transmission efficiency of electrons, thereby reducing series loss and recombination loss, enhancing the current collection efficiency, and thus improving the photoelectric conversion efficiency of the entire solar cell.

[0042] 2. Enhance device stability: Since the electrode material layer is prepared by a low-temperature, low-energy deposition process, the thermal damage to the perovskite layer caused by traditional high-temperature annealing is avoided, which can effectively protect the structural stability of the perovskite layer and improve the working stability and long-term reliability of the entire solar cell.

[0043] 3. Improve light transmittance: Using a highly light-transmitting electrode material layer can ensure that more light can pass through, increase the utilization of light, and thus improve the overall efficiency of solar cells. Especially in photovoltaic applications, it can optimize the light absorption process.

[0044] 4. Optimize the interface matching of the device: The conductive film has good surface quality and low defect density, which can form a good interface matching with other material layers such as the perovskite layer and the electron transport layer, reduce interface defects, improve carrier transfer efficiency, and further improve the overall performance of the battery.

[0045] 5. Low cost and environmental protection: The method of the present invention can reduce manufacturing costs and reduce dependence on high temperature and complex processes through low-temperature preparation and optimized nitrogen doping process. At the same time, the use of environmentally friendly materials and processes helps to improve the sustainability and production efficiency of optoelectronic devices.

[0046] 6. Expanded application scope: The improvements in optoelectronic performance, stability and process feasibility of the stacked perovskite solar cell make it more advantageous in large-scale production and suitable for a variety of optoelectronic applications, especially in high-efficiency and low-cost solar cell technology.

[0047] According to some embodiments of the present invention, the method for preparing the perovskite precursor solution includes: dissolving PbI2 and CH3NH3I in a mixed solution of N,N-dimethylformamide and dimethyl sulfoxide.

[0048] According to some embodiments of the invention, the anti-solvent comprises chlorobenzene.

[0049] According to some embodiments of the present invention, the evaporation rate is 0.4 nm / s to 0.5 nm / s.

[0050] The fourth aspect of the present invention provides a method for preparing the tandem perovskite solar cell according to the third aspect of the present invention, comprising the following steps:

[0051] S1: performing magnetron sputtering coating on the heterojunction substrate to form the hole transport layer;

[0052] S2: after spin coating the perovskite precursor solution on the surface of the hole transport layer, adding an anti-solvent dropwise, and heating to form the perovskite layer;

[0053] S3: performing evaporation deposition on the surface of the perovskite layer to form the electron transport layer;

[0054] S4: placing the product of step S3 in a coating device for coating to form the electrode material layer;

[0055] S5: printing silver grid lines on the surface of the product of step S4 to form the electrode.

[0056] A technical solution in the method for preparing a laminated perovskite solar cell of the present invention has at least the following beneficial effects:

[0057] This preparation method realizes the high-efficiency, low-temperature preparation of stacked perovskite solar cells by combining processes such as magnetron sputtering, spin coating, evaporation and plasma coating. This method can accurately control the thickness and performance of each layer while ensuring the structural integrity of the perovskite layer, optimizing the charge transfer and collection efficiency of the device. In particular, when preparing the electrode material layer, reactive plasma coating is used to achieve a high-mobility, high-transparency conductive film under low-temperature conditions, avoiding the thermal damage to the perovskite layer caused by traditional high-temperature annealing, and improving the stability and photoelectric performance of the battery. In addition, the overall process is simple, environmentally friendly and has good process repeatability, which is suitable for large-scale production and has high economic benefits and application prospects.

[0058] In the present invention, "low temperature" means that the substrate temperature is less than 100°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a schematic diagram of the structure of reactive plasma coating equipment.

[0060] Figure 2 The work function test results of the conductive film with IWO as the target material.

[0061] Figure 3 The work function test results of the conductive film with IWO-N as the target material.

[0062] Figure 4 This is the XRD test result of IWO-N single film. DETAILED DESCRIPTION

[0063] The following are specific embodiments of the present invention, and the technical solutions of the present invention are further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0064] In the first aspect, some embodiments of the present invention provide a method for preparing a conductive film, comprising the following steps: placing a substrate in a coating device, evacuating the substrate, setting a target material, and introducing gas for coating, wherein the gas is nitrogen or a mixture of nitrogen and oxygen, and the flow ratio of nitrogen to oxygen in the mixed gas is 0.1 to 10:1.

[0065] It should be noted that the preparation method of the conductive film of the present invention can prepare a high-mobility indium-based oxide film material at room temperature by forming the film in a low-bombardment device. Nitrogen doping enhances the localization of surface charges and improves the mobility of the film layer at room temperature.

[0066] It should also be noted that for reactive plasma coating, a certain amount of argon needs to be introduced for ignition. Therefore, a certain amount of argon is contained in the reaction process. Since the function of argon is ignition, the specific amount of introduction can be adjusted according to the equipment model, and the present invention does not make any provisions.

[0067] Furthermore, the method for preparing the conductive film of the present invention can also bring the following beneficial effects:

[0068] Improve the optical properties of the film: Nitrogen doping can adjust the optical band gap of the film, making it have a higher light transmittance. For conductive films, higher light transmittance helps to use sunlight more efficiently and improve the photoelectric conversion efficiency of solar cells. Nitrogen doping can not only improve the conductivity of the film, but also reduce the absorption of visible light, improve the transparency of the film, and optimize its performance in optoelectronic applications.

[0069] Improved chemical stability of the film: Nitrogen-doped films may have higher chemical stability. The stability of the film is crucial under long-term working conditions such as solar cells. Nitrogen doping can enhance the corrosion resistance of indium-based oxides, improve the stability of the film in the environment, especially in the presence of humidity and oxygen, which can extend the service life of the film and improve the reliability of optoelectronic devices.

[0070] Reduced manufacturing costs: The conductive film preparation method is carried out under low temperature and low bombardment energy conditions, which reduces the reliance on expensive post-processing processes such as high temperature annealing. The low temperature deposition process helps reduce the demand for equipment and energy, thereby reducing manufacturing costs, which is especially important for cost control in large-scale production.

[0071] Improve the conductivity of the film: Nitrogen doping enhances the electron mobility of the film and improves the conductivity. This is particularly important for the application of conductive films in electronic devices, especially in stacked perovskite solar cells, which require conductive films to have high mobility to ensure smooth conduction of current, thereby improving the efficiency of the entire photovoltaic device.

[0072] Improve the structure and surface quality of the film: Nitrogen doping may change the microstructure of the film, making its surface smoother and reducing surface defects and unevenness. This can improve the uniformity of the film, further improve the interface matching between the film and other layers (such as the perovskite layer), reduce interface defects, reduce carrier recombination, and improve the overall efficiency of the device.

[0073] Improved adjustability and functionality: By controlling the flow ratio of nitrogen and oxygen, the nitrogen doping method can adjust the electrical and optical properties of the conductive film and increase the adjustability of the film. This provides flexibility for different application fields, and the conductivity, transparency and other properties of the film can be adjusted according to actual needs, thereby optimizing the performance of different types of optoelectronic devices.

[0074] In combination with the first aspect, in some embodiments of the present invention, the coating equipment is a reactive plasma coating equipment.

[0075] In combination with the first aspect, in some embodiments of the present invention, the target material includes tin oxide or indium-based oxide.

[0076] In combination with the first aspect, in some embodiments of the present invention, the indium-based oxide includes at least one of indium tungsten oxide (IWO), indium zinc oxide (IZO), indium cerium oxide (ICO), indium gallium oxide, indium strontium oxide, indium copper oxide and indium cobalt oxide.

[0077] In combination with the first aspect, in some embodiments of the present invention, in the mixed gas of nitrogen and oxygen, the flow ratio of nitrogen to oxygen is 1 to 4:1.

[0078] The flow ratio of nitrogen and oxygen is in the preferred range of 1:1 to 4:1, which helps to optimize the performance of the conductive film under low-energy deposition conditions. This ratio can balance the concentration of nitrogen doping, improve the conductivity and electron mobility of the film, while maintaining high light transmittance and optical properties. It can also improve the chemical stability and structural quality of the film, reduce defects, and improve the uniformity of the film, thereby achieving higher efficiency and long-term stability in stacked perovskite solar cells.

[0079] In a second aspect, some embodiments of the present invention provide a conductive film, which is prepared by the preparation method of the first aspect of the present invention.

[0080] The conductive film is prepared by the preparation method of the first aspect of the present invention, which has the following beneficial effects:

[0081] 1. High mobility: Nitrogen doping can optimize the electronic structure of the film and significantly improve its electron mobility, thereby enhancing the conductivity of the transparent conductive film and ensuring more efficient current transmission. This is crucial for optoelectronic devices, especially current collection and transmission of stacked perovskite solar cells.

[0082] 2. Improve optical properties: Nitrogen doping helps to adjust the optical band gap of the film, maintain a high light transmittance, and optimize its optical properties in the visible and infrared regions. This can effectively improve the photoelectric conversion efficiency, especially in optoelectronic applications such as solar cells, and improve the utilization of sunlight.

[0083] 3. Improve chemical stability: After nitrogen is doped into the film, it helps to improve the chemical stability of the film, making it better resistant to moisture and oxygen environments. This provides higher reliability and service life for optoelectronic devices that work for a long time.

[0084] 4. Reduce film defects: Nitrogen doping can improve the microstructure of the film, reduce the defect density in the film, and improve the uniformity and surface quality of the film. This is crucial for reducing interface defects, improving carrier collection efficiency, reducing recombination losses, and enhancing the overall efficiency of the device.

[0085] 5. Low-temperature preparation: The low-energy, low-temperature deposition method of the present invention can achieve high-quality preparation of thin films at room temperature, avoiding thermal damage to perovskite solar cells that may be caused by high-temperature annealing. In particular, when the perovskite layer is more sensitive to high temperatures, it can ensure that the performance of the device is not affected.

[0086] 6. The process is simple and energy-saving: The present invention adopts low-energy deposition technology and does not require post-processing such as high-temperature annealing. It can reduce energy consumption in the preparation process, reduce production costs, and has high process feasibility and economic benefits.

[0087] Therefore, the conductive film prepared by the present invention has significant advantages in terms of conductivity, optical properties, stability and preparation process, so that it has broad application prospects in stacked perovskite solar cells and other optoelectronic devices. Specifically, when pure nitrogen is selected, it is suitable for applications that need to improve electron mobility and conductivity, especially when light transmittance is not required. Pure nitrogen helps to improve the conductivity of the film, but it will reduce the light transmittance. Selecting a mixed gas of nitrogen and oxygen is suitable for applications that need to balance conductivity and light transmittance, especially in solar cells and transparent electrodes, which can improve the optical properties, chemical stability, surface quality and structural stability of the film, extend the service life and enhance long-term stability. By adjusting the ratio of nitrogen and oxygen, the various properties of the film can be optimized to meet the needs of different applications.

[0088] In combination with the second aspect, in some embodiments of the present invention, the thickness of the conductive film is 10 nm to 100 nm.

[0089] In combination with the second aspect, in some embodiments of the present invention, the thickness of the conductive film is 60 nm to 80 nm.

[0090] The thickness of the conductive film is within the range of 60nm to 80nm, which can ensure good conductivity and high mobility while maintaining high transparency and appropriate optical properties. This film thickness can provide sufficient conductivity paths, optimize current transmission efficiency, and effectively control the light transmittance of the film to ensure effective use of light. In addition, this film thickness range can also ensure a flat film surface, reduce defects, improve the uniformity and structural stability of the film, and enhance the overall performance and reliability of the device.

[0091] In combination with the second aspect, in some embodiments of the present invention, the film thickness of the conductive film can be any value of 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm or a range formed by any two of them, such as 60nm~80nm or 20nm~50nm.

[0092] In combination with the second aspect, in some embodiments of the present invention, when the target material for preparing the conductive film is an IWO target material, the transmittance of the conductive film is ≥87%, and the mobility of the conductive film is ≥45cm 2 / V·s, the square resistance of the conductive film is less than 70Ω / □.

[0093] In combination with the second aspect, in some embodiments of the present invention, when the target material for preparing the conductive film is an IZO target material, the transmittance of the conductive film is ≥85%, and the mobility of the conductive film is ≥60cm 2 / V·s, the square resistance of the conductive film is less than 55Ω / □.

[0094] In combination with the second aspect, in some embodiments of the present invention, when the target material for preparing the conductive film is an ICO target material, the transmittance of the conductive film is ≥78%, and the mobility of the conductive film is ≥45cm 2 / V·s, the square resistance of the conductive film is less than 55Ω / □.

[0095] The high transmittance of the conductive film means that the film has a high light transmittance while ensuring excellent conductivity. This helps to maximize the use of sunlight and improve the efficiency of photoelectric conversion. Especially in photovoltaic applications, it can effectively allow more light to pass through the film and be absorbed by the underlying material, thereby enhancing the photoelectric performance of solar cells. In addition, high transmittance can also ensure the transparency of the film in the photoelectric device, reduce light loss, and improve the overall efficiency and performance of the device.

[0096] The high mobility of the conductive film means that the film has excellent electron transport capabilities. This high mobility can significantly improve the current transmission efficiency, reduce electron recombination, and thus enhance the overall performance of optoelectronic devices, especially solar cells. High mobility allows electrons to move more quickly in the film, improving the conductivity and response speed of the conductive film in the optoelectronic device, thereby improving the photoelectric conversion efficiency and optimizing the working performance and stability of the device.

[0097] The small square resistance of the conductive film means that the film has a lower resistance, which helps to improve its conductivity and reduce energy loss during current transmission. Low square resistance can ensure more efficient electron flow, reduce series current losses, and improve the overall performance of optoelectronic devices. For optoelectronic devices such as solar cells, low square resistance films can effectively improve current collection and transmission efficiency, thereby improving photoelectric conversion efficiency and the overall performance of the device.

[0098] In a third aspect, some embodiments of the present invention provide a stacked perovskite solar cell, comprising a heterojunction substrate, a hole transport layer, a perovskite layer, an electron transport layer, an electrode material layer and an electrode arranged in sequence, wherein the electrode material layer is prepared by the preparation method of the first aspect of the present invention.

[0099] The electrode material layer of the laminated perovskite solar cell prepared by the preparation method of the first aspect of the present invention has the following significant beneficial effects:

[0100] 1. Improve the photoelectric conversion efficiency: The electrode material layer has low resistance and high mobility, which can effectively improve the transmission efficiency of electrons, thereby reducing series loss and recombination loss, enhancing the current collection efficiency, and thus improving the photoelectric conversion efficiency of the entire solar cell.

[0101] 2. Enhance device stability: Since the electrode material layer is prepared by a low-temperature, low-energy deposition process, the thermal damage to the perovskite layer caused by traditional high-temperature annealing is avoided, which can effectively protect the structural stability of the perovskite layer and improve the working stability and long-term reliability of the entire solar cell.

[0102] 3. Improve light transmittance: Using a highly light-transmitting electrode material layer can ensure that more light can pass through, increase the utilization of light, and thus improve the overall efficiency of solar cells. Especially in photovoltaic applications, it can optimize the light absorption process.

[0103] 4. Optimize the interface matching of the device: The conductive film has good surface quality and low defect density, which can form a good interface matching with other material layers such as the perovskite layer and the electron transport layer, reduce interface defects, improve carrier transfer efficiency, and further improve the overall performance of the battery.

[0104] 5. Low cost and environmental protection: The method of the present invention can reduce manufacturing costs and reduce dependence on high temperature and complex processes through low-temperature preparation and optimized nitrogen doping process. At the same time, the use of environmentally friendly materials and processes helps to improve the sustainability and production efficiency of optoelectronic devices.

[0105] 6. Expanded application scope: The improvements in optoelectronic performance, stability and process feasibility of the stacked perovskite solar cell make it more advantageous in large-scale production and suitable for a variety of optoelectronic applications, especially in high-efficiency and low-cost solar cell technology.

[0106] In tandem perovskite solar cells, when pure nitrogen is selected, it is suitable for applications with high requirements for electron mobility. It can improve the conductivity and mobility of the film, but it may reduce the light transmittance, so it is suitable for parts that do not require high light transmittance. Selecting a mixture of nitrogen and oxygen helps to balance the conductivity and light transmittance, improve the optical properties and chemical stability of the film, improve the surface quality, and extend the service life of the device. By adjusting the ratio of nitrogen and oxygen, the various properties of the film can be optimized to improve the overall efficiency and stability of the tandem perovskite solar cell.

[0107] The heterojunction substrate is the base part of the perovskite solar cell, which is usually composed of silicon or other materials (such as transparent conductive oxides, TCO, etc.). The substrate not only provides mechanical support for the battery, but also may participate in carrier collection. If a silicon substrate is used, a heterojunction is formed between it and the perovskite layer, which can effectively enhance the photoelectric conversion efficiency. In this structure, the substrate provides the basis for light irradiation and electron carrier conduction, forming a favorable environment for the generation of photogenerated carriers.

[0108] The hole transport layer is located between the perovskite layer and the electrode. It is mainly responsible for collecting holes from the perovskite light absorption layer and directing the holes to the electrode. NiOx film is often used as a hole transport layer material because it has high hole mobility, good transparency and excellent electrochemical stability. This layer can reduce the recombination of holes in the perovskite layer, enhance the conductivity of holes, prevent carrier recombination, and ensure maximum battery efficiency.

[0109] The perovskite layer is the light-absorbing layer of the solar cell. Its main function is to absorb photons and generate photogenerated electron-hole pairs (photogenerated carriers). The band structure of the perovskite material can optimize the generation and separation of photogenerated carriers. After photons irradiate the perovskite layer, the electrons and holes are separated and conducted to the electron transport layer and the hole transport layer respectively. The light absorption characteristics of the perovskite layer directly affect the photoelectric conversion efficiency of the solar cell.

[0110] The electron transport layer is located between the perovskite layer and the electrode, and is responsible for collecting the electrons generated in the perovskite layer and conducting them to the electrode. Commonly used ETL materials include TiO2, ZnO and other materials with high electron mobility and good electron transport capabilities. The electron transport layer can improve the conductivity of electrons and effectively prevent the recombination of electrons and holes, ensuring that electrons can flow smoothly to the electrode, thereby improving the photoelectric conversion efficiency.

[0111] The electrode material layer is located between the electron transport layer and the electrode, and is usually made of a transparent conductive material (such as ITO, FTO or Ag, etc.). This layer of material can both conduct electricity and allow light to pass through. On the one hand, this layer allows electrons to pass smoothly and be directed to the external circuit, and on the other hand, it also allows some light to pass through to enhance light absorption and conversion, especially when the perovskite light absorption layer is thick.

[0112] The electrode is the output end of the solar cell, which is used to guide the electrons and holes collected from the inside of the battery to the external circuit to form an electric current. In this structure, the electrode is usually made of metal materials (such as gold, silver, etc.). The main function of the electrode is to connect to the external circuit, provide current output, and collect photogenerated carriers. The electrode must also have good conductivity to ensure the current transmission efficiency of the battery.

[0113] In combination with the third aspect, in some embodiments of the present invention, the method for preparing the perovskite precursor solution includes: dissolving PbI2 and CH3NH3I in a mixed solution of N,N-dimethylformamide and dimethyl sulfoxide.

[0114] In conjunction with the third aspect, in some embodiments of the present invention, the anti-solvent includes chlorobenzene.

[0115] In combination with the third aspect, in some embodiments of the present invention, the evaporation rate is 0.4 nm / s to 0.5 nm / s.

[0116] In a fourth aspect, in some embodiments of the present invention, there is provided a method for preparing the tandem perovskite solar cell according to the third aspect of the present invention, comprising the following steps:

[0117] S1: magnetron sputtering is performed on the heterojunction substrate to form a hole transport layer;

[0118] S2: After spin coating the perovskite precursor solution on the surface of the hole transport layer, an anti-solvent is added dropwise and heated to form a perovskite layer;

[0119] S3: performing evaporation deposition on the surface of the perovskite layer to form an electron transport layer;

[0120] S4: placing the product of step S3 in a coating device for coating to form an electrode material layer;

[0121] S5: Printing silver grid lines on the surface of the product of step S4 to form electrodes.

[0122] It can be understood that the preparation method realizes efficient and low-temperature preparation of stacked perovskite solar cells by combining processes such as magnetron sputtering, spin coating, evaporation and plasma coating. This method can accurately control the thickness and performance of each layer while ensuring the structural integrity of the perovskite layer, and optimize the charge transfer and collection efficiency of the device. In particular, when preparing the electrode material layer, reactive plasma coating is used to achieve a high-mobility, high-transparency conductive film under low-temperature conditions, avoiding the thermal damage of the perovskite layer by traditional high-temperature annealing, and improving the stability and photoelectric performance of the battery. In addition, the overall process is simple, environmentally friendly and has good process repeatability, which is suitable for large-scale production and has high economic benefits and application prospects.

[0123] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0124] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0125] Unless otherwise specified, "room temperature" in the present invention means 25°C±5°C.

[0126] Unless otherwise specified, "about" in the present invention means that the allowable error is within ±2%.

[0127] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0128] In the embodiment, N2:O2 refers to the flow ratio of N2 and O2, and the total flow rate is 70 sccm.

[0129] Example 1

[0130] The conductive film was prepared by placing clean ultra-white glass on a transmission carrier, opening the gate valve, and passing through the transmission carrier into the C1 cavity. Figure 1 As shown, close the gate valve and draw the vacuum degree to 0.04Pa;

[0131] Open the gate valve, transfer the carrier into the C4 chamber, close the gate valve, use indium-based oxides IWO, IZO and ICO as targets, introduce different proportions of reaction gases for reactive plasma coating (equipment model RSE1000T). Control the coating pressure to 0.2-1Pa to obtain indium nitride-based oxide films.

[0132] The square resistance, film thickness, transmittance and mobility of the prepared conductive film were tested, and the results are shown in Tables 1 to 3.

[0133] Table 1 Target material is IWO

[0134]

[0135]

[0136] Table 2 Target material is IZO

[0137] Square resistance (Ω / □) Film thickness(nm) Transmission(%) <![CDATA[Mobility (cm 2 / V·s)]]> <![CDATA[N2:O2=(10:0)]]> 47 70 85 80 <![CDATA[N2:O2=(4:1)]]> 46 71 88.2 73 <![CDATA[N2:O2=(1:1)]]> 45 73 88.4 65 <![CDATA[N2:O2=(1:4)]]> 54 72 89 60 <![CDATA[N2:O2=(0:10)]]> 58 72 90 45

[0138] Table 3 Target material is ICO

[0139] Square resistance (Ω / □) Film thickness(nm) Transmission(%) <![CDATA[Mobility (cm 2 / V·s)]]> <![CDATA[N2:O2=(10:0)]]> 47 70 78 62 <![CDATA[N2:O2=(4:1)]]> 46 71 78.2 56 <![CDATA[N2:O2=(1:1)]]> 45 73 78.4 54 <![CDATA[N2:O2=(1:4)]]> 54 72 82 45 <![CDATA[N2:O2=(0:10)]]> 58 72 80 34

[0140] It can be seen from Tables 1 to 3 that the conductive film with IZO as the target material exhibits good comprehensive performance, especially in conductivity and mobility, and is suitable for applications requiring high transparency and high mobility.

[0141] The transmittance and mobility of the conductive film whose target material is IWO are relatively balanced.

[0142] Furthermore, the work function of the conductive film with a film thickness of 70 nm and a target material of IWO was characterized. The results are shown in Table 4. Figure 2 and Figure 3 shown.

[0143] Table 4

[0144]

[0145]

[0146] The size of the work function directly reflects the strength of electron binding in the solid. The larger the work function, the more difficult it is for electrons to leave the solid surface; conversely, the smaller the work function, the easier it is for electrons to escape. As the top electrode material in contact with C60, the single film is required to have high mobility. The indium nitride-based oxide film prepared in this way can reduce the work function of the conductive film material, improve the mobility of the single film, and improve the bandgap matching adaptation of the device.

[0147] In Table 4, "IWO-N" indicates the case where the N2:O2 ratio is 4:1.

[0148] Furthermore, XRD analysis was performed on the IWO-N single film (N2:O2 ratio is 10:0), as shown in Figure 4 The characteristic peaks of InN appear at 28° and 32°, indicating that the prepared film is a nitrogen-doped indium-based oxide film IWO-N.

[0149] ICO has low transmittance and mobility.

[0150] Therefore, if conductivity and mobility are prioritized, IZO is the best choice. If transmittance is taken into consideration, IWO will be a compromise choice.

[0151] If it is pure nitrogen condition, it will have higher mobility and lower transmittance.

[0152] In the case of pure oxygen, the square resistance increases significantly, the mobility decreases, and the conductivity decreases.

[0153] Therefore, pure nitrogen or a mixture of nitrogen and oxygen can be selected to prepare the conductive film according to actual needs. Specifically:

[0154] Suitable situations for choosing pure nitrogen may be:

[0155] Pure nitrogen-doped films usually provide higher electron mobility because nitrogen doping enhances the conductivity of the film and reduces the negative effects of oxygen. Under low-energy deposition conditions, pure nitrogen helps improve the conductivity of the film, especially in applications that require fast electron mobility, such as high-frequency electronic devices, transparent conductive electrodes, etc.

[0156] If the device has high conductivity requirements, such as in some electronic devices or high-performance solar cells, pure nitrogen can help improve the conductivity of the film and reduce the resistance of the material.

[0157] Pure nitrogen doping will reduce the light transmittance of the conductive film and is suitable for applications that do not require high light transmittance. If the optical transparency of the film is not the main indicator (such as some types of transparent electrodes or conductive layers), pure nitrogen will be more preferred.

[0158] Suitable gas mixtures of nitrogen and oxygen may be:

[0159] Since the nitrogen and oxygen gas mixture helps adjust the optical band gap of the film, the film has a high light transmittance. In applications such as solar cells and photovoltaic devices, high light transmittance is very important. The choice of nitrogen and oxygen mixed gas can take into account both conductivity and light transmittance, especially when light transmittance is critical to device efficiency.

[0160] Oxygen doping can improve the chemical stability of the film, especially its corrosion resistance. For applications that work in a humid or oxygen environment for a long time (such as solar cells), mixed gases (nitrogen and oxygen) can keep the film stable during long-term use and extend its service life.

[0161] Mixed doping of nitrogen and oxygen can change the microstructure of the film, improve surface quality, reduce defects and inhomogeneities, and thus optimize the physical properties of the film. For applications with high requirements on surface quality, such as transparent conductive electrodes, display devices, etc., mixed gas preparation can provide better surface smoothness and uniformity.

[0162] Therefore, if the application requires a balance between conductivity and light transmittance, such as in perovskite solar cells, the doping of nitrogen and oxygen mixed gases can adjust the performance of the film according to the ratio. The flow ratio of the mixed gas can optimize the conductivity, mobility and light transmittance of the film under low-energy deposition conditions, providing more balanced performance.

[0163] Example 2

[0164] The stacked perovskite solar cell was prepared, and the specific steps were as follows:

[0165] 1. The heterojunction substrate was cleaned with a dry ultrasonic device for 15 minutes, and then placed in a UV ozone machine for 15 minutes to remove organic impurities on its surface.

[0166] 2. Preparation of hole transport layer: Send the cleaned heterojunction substrate into the magnetron sputtering coating equipment to sputter 10nm NiO x film.

[0167] 3. Preparation of perovskite layer: Weigh 0.4610g PbI2 and 0.1589g CH3NH3I and dissolve them in a mixed solution of N,N-dimethylformamide DMF and dimethyl sulfoxide DMSO (volume ratio of 4:1) to prepare a 1.2mol / L perovskite precursor solution. Spin coat the hole transport layer at 5000r / min for 30s, add 200μL chlorobenzene antisolvent at the 6th second, and then heat on a heating table at 105°C for 30min. Among them, the antisolvent is a dispersing solvent for extracting perovskite, so that the perovskite is initially crystallized. Heating on a heating table at 105°C for 30min is to crystallize the perovskite, and the temperature range can be between 100-150°C.

[0168] 4. Preparation of electron transport layer: Place the substrate with hole transport layer and perovskite layer in a vacuum coating machine at 8×10 □4 A 15 nm thick C60 film was evaporated on the perovskite layer as an electron transport layer under a vacuum degree of 1.5 Pa, and the evaporation rate was 0.4-0.5 nm / s.

[0169] 5. Preparation of electrode materials: The substrate having the hole transport layer, the perovskite layer and the electron transport layer is placed in a reactive plasma deposition coating device, and the method of Example 1 is referred to. -1 Under a vacuum degree of 1.5 Pa, in different gas atmospheres (for specific gases, see Table 5), 70 nm of electrode material, ie, a conductive film, was deposited on the electron transport layer.

[0170] 6. Prepare silver electrode: Place the above electrode layer and substrate on a screen printing device to print silver grid lines.

[0171] In this embodiment, the target material used is IWO target material.

[0172] The performance of the stacked perovskite solar cells was tested and the results are shown in Table 5.

[0173] Table 5

[0174] Voc(V) <![CDATA[Jsc(mA / cm 2 )]]> FF(%) Eff(%) <![CDATA[N2:O2=(10:0)]]> 1.65 18.02 70.2 20.87 <![CDATA[N2:O2=(4:1)]]> 1.77 18.19 78.2 25.18 <![CDATA[N2:O2=(1:1)]]> 1.73 18.20 66.2 20.84 <![CDATA[N2:O2=(1:4)]]> 1.75 18.04 60.2 19.01 <![CDATA[N2:O2=(0:10)]]> 1.7 18.01 54 16.53

[0175] From Table 5 we can see that:

[0176] 1. The open circuit voltage (Voc) varies between 1.65V and 1.77V, showing some fluctuations.

[0177] When the ratio of N2:O2 is 4:1, Voc reaches the highest value of 1.77V, which shows that the voltage performance of the battery is the best under this ratio. The Voc values ​​under other ratios are relatively low, especially when N2:O2=(10:0), Voc is only 1.65V.

[0178] 2. The short-circuit current density (Jsc) varies little under various conditions, and basically remains at 18.01 to 18.20 mA / cm 2 The variation is small, indicating that the photocurrent generation is less affected by the change of N2:O2 ratio. Under the condition of N2:O2=(1:1), Jsc is slightly higher (18.20mA / cm 2 ), but overall, the Jsc is not much different.

[0179] 3. The fill factor (FF) shows a significant change, reaching a maximum value of 78.2% when N2:O2=(4:1), which shows that the internal current transmission efficiency of the battery is optimal under this ratio. The FF under other ratios is relatively low, especially when N2:O2=(0:10), the FF is only 54%, the worst performance.

[0180] The larger the FF (filling factor), the smaller the bombardment of this molding method.

[0181] 4. The photoelectric conversion efficiency (Eff) shows obvious differences under different gas ratios. The highest efficiency is 25.18% when N2:O2=(4:1), indicating that the overall performance of the battery is the best under this ratio. The efficiency under other conditions is poor, especially when N2:O2=(0:10), the efficiency is only 16.53%.

[0182] N2:O2=(4:1) is the optimal gas ratio condition. Under this ratio, the solar cell exhibits the highest Voc, FF and Eff, indicating that the battery performance is the best under this condition.

[0183] The present invention has been described in detail above in conjunction with the embodiments, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A method for preparing a conductive film, characterized in that: The method comprises the following steps: placing a substrate in a coating device, evacuating the substrate, setting a target material, introducing a gas for coating, wherein the gas is nitrogen or a mixed gas of nitrogen and oxygen, and the flow ratio of nitrogen to oxygen in the mixed gas is 0.1 to 10:

1.

2. The preparation method according to claim 1, characterized in that: The target material includes tin oxide or indium-based oxide; and / or the indium-based oxide includes at least one of indium tungsten oxide, indium zinc oxide, indium gallium oxide, indium strontium oxide, indium copper oxide, indium cerium oxide and indium cobalt oxide.

3. The preparation method according to claim 1 or 2, characterized in that: In the mixed gas of nitrogen and oxygen, the flow ratio of nitrogen to oxygen is 1 to 4:

1.

4. A conductive film, characterized in that: Prepared by the preparation method described in any one of claims 1 to 3.

5. The conductive film according to claim 4, characterized in that: The thickness of the conductive film is 10nm-100nm; and / or, when the target material for preparing the conductive film is an IWO target material, the transmittance of the conductive film is ≥87%, and the mobility of the conductive film is ≥45cm 2 / V·s, the square resistance of the conductive film is less than 70Ω / □; and / or when the target material for preparing the conductive film is an IZO target material, the transmittance of the conductive film is ≥85%, and the mobility of the conductive film is ≥60cm 2 / V·s, the square resistance of the conductive film is less than 55Ω / □; and / or when the target material for preparing the conductive film is an ICO target material, the transmittance of the conductive film is ≥78%, and the mobility of the conductive film is ≥45cm 2 / V·s, and the square resistance of the conductive film is less than 55Ω / □.

6. A laminated perovskite solar cell, characterized in that: The method comprises a heterojunction substrate, a hole transport layer, a perovskite layer, an electron transport layer, an electrode material layer and an electrode arranged in sequence, wherein the electrode material layer comprises a conductive film prepared by the preparation method according to any one of claims 1 to 3 or a conductive film according to any one of claims 4 to 5.

7. A method for preparing the tandem perovskite solar cell according to claim 6, characterized in that: The following steps are involved: S1: performing magnetron sputtering coating on the heterojunction substrate to form the hole transport layer; S2: after spin coating the perovskite precursor solution on the surface of the hole transport layer, adding an anti-solvent dropwise, and heating to form the perovskite layer; S3: performing evaporation deposition on the surface of the perovskite layer to form the electron transport layer; S4: placing the product of step S3 in a coating device for coating to form the electrode material layer; S5: printing silver grid lines on the surface of the product of step S4 to form the electrode.

8. The method according to claim 7, characterized in that The method for preparing the perovskite precursor solution comprises: PbI2 and CH3NH3I were dissolved in a mixed solution of N,N-dimethylformamide and dimethyl sulfoxide.

9. The method according to claim 7, characterized in that: The anti-solvent includes chlorobenzene.

10. The method according to claim 7, characterized in that The evaporation rate is 0.4 nm / s to 0.5 nm / s.

Images