In-situ preparation method of temperature sensing electrode for silicon-based photovoltaic cell

Abstract

The invention belongs to the technical field of electronic materials, and particularly relates to an in-situ preparation method of a temperature sensing electrode for a silicon-based photovoltaic cell. According to the method, the nickel-based temperature sensing electrode is prepared by combining laser grooving with chemical plating and is used for temperature-sensitive characteristic testing. A response surface analysis method is adopted to optimize process technical parameters as follows: the nickel sulfate content is 125 g / L, the sodium hypophosphite content is 112 g / L, the plating temperature is 51 DEG C, and the pH value of a plating solution is 8.9; the nickel-based temperature sensing electrode is high in sensitivity (0.86% / DEG C) and good in linearity in the range of 30-70 DEG C. The temperature sensing electrode has application potential in the aspect of realizing intelligentization of a silicon-based photovoltaic cell temperature control system.

Description

Technical Field

[0001] The invention belongs to the field of electronic materials, and in particular relates to an in-situ preparation method of a temperature sensing electrode for a silicon-based photovoltaic cell. Background Art

[0002] With the large-scale development of the industry, the operating efficiency and life of photovoltaic power stations are affected by various environmental factors, which also brings huge challenges to the monitoring and operation and maintenance of photovoltaic power stations [Abdulla H, Sleptchenko A, Nayfeh A.Photovoltaic systems operation and maintenance: A review and future directions. Renewable and Sustainable Energy Reviews, 2024, 195: 114342.]. In this context, intelligent operation and maintenance has gradually become an inevitable trend in the development of photovoltaic operation and maintenance technology [Utama I, Pamungkas RF, Faridh M, et al. Intelligent IoT platform for multiple PV plant monitoring. Sensors, 2023, 23(15): 6674.], and intelligent operation and maintenance technology can be divided into digital operation and maintenance and intelligent equipment, which needs to be based on environmental parameters [Novak M, Vohnout R, Landkamer L, et al. Energy-efficient smart solar system cooling for real-time dynamic weather changes inmild-climate regions. Renewable and Sustainable Energy Reviews, 2023, 182:113347.]. Various environmental parameters can reflect the operating status of photovoltaic power plants to varying degrees, among which temperature is a crucial parameter [Bourisli RI, Zaher FA, Aldalali B S. Reducing the operating temperature and improving the efficiency of PV modules using guiding vanes. Solar Energy, 2024, 269: 112345.], which is mainly reflected in the following aspects: (1) Temperature parameters can provide a reference for power station performance evaluation and optimization. By analyzing the relationship between temperature and power generation, the actual power generation performance of the power station can be more accurately evaluated, providing a basis for performance improvement. The output power of photovoltaic modules is closely related to temperature [Sun C, Zou Y, Qin C, et al. Temperature effect of photovoltaic cells: A review. Advanced Composites and Hybrid Materials, 2022, 5: 2675-2699.] , and increased temperature will lead to a decrease in the efficiency of photovoltaic cells. Therefore, by monitoring the temperature, the operating conditions of the power station can be optimized, such as combining the heat dissipation system to intelligently reduce the temperature of the components, thereby improving the power generation efficiency. (2) Combined with temperature data, fault diagnosis and equipment protection of the power station can be performed. Temperature abnormality is one of the early indicators of equipment failure [Song Y, Zou S, Dong Q, et al. A temperature-dependent fire risk assessment framework for solar photovoltaic station. Sustainable Energy Technologies and Assessments, 2023, 60: 103467.] . By monitoring temperature changes, potential problems can be discovered in time, preventive maintenance can be performed, downtime can be reduced, and the continuous operation of the power station can be ensured. High temperatures may cause damage to key equipment such as photovoltaic modules and inverters. By monitoring temperature in real time, equipment overheating can be prevented, potential failures and damage can be avoided, and the service life of the equipment can be extended.

[0003] Response surface analysis modeling (RSM) is a method for optimizing and studying complex systems. It combines experimental design and mathematical modeling to study the effects of multiple factors and their interactions on one or more response variables. Compared with orthogonal experiments, it is impossible to obtain a clear functional expression of the relationship between factors and target responses in the target analysis area, and the number of experiments is huge when there are many levels of factors. The response surface analysis modeling has the advantages of fewer experiments, shorter experimental cycles, model visualization, and high prediction reliability. It can be effectively applied to the factors and responses designed for processing and analysis. Before constructing a response surface approximate model, the relationship between the design variables (analysis factors) and the analysis targets (response values) should be clarified, and a suitable function form should be selected to describe the relationship between the current design variables and the analysis targets. By constructing an appropriate prediction model, researchers can easily and efficiently analyze and evaluate the relationship between the factors and intuitively determine the optimal process parameters under the target response.

[0004] Nickel materials have thermal resistance and temperature sensitivity and are often used in temperature sensors. However, their temperature sensitivity is affected by the substrate and preparation process. The fundamental reason is that the microstructures of nickel films generated under different conditions are different. The thermal resistance and temperature sensitivity under different microstructures vary greatly. Some have positive temperature coefficient effects, some have negative temperature coefficient effects, and some have zero temperature coefficient effects that are insensitive to temperature. Therefore, for silicon-based photovoltaic cells, it is always a challenge to obtain the optimal temperature sensing sensitivity of in-situ prepared temperature-sensing electrodes to improve the intelligence of photovoltaic control systems.

[0005] The present invention uses response surface analysis to establish a corresponding relationship model between the in-situ generated temperature sensing electrode preparation technical parameters and the temperature sensing sensitivity, optimizes the preparation technical parameters based on an algorithm, obtains the optimal temperature sensing sensitivity, and verifies the accuracy of the model through experiments. This improves the research and development efficiency in the field of silicon-based photovoltaic cell temperature sensing, reduces the blindness of research and development, and is innovative. Summary of the invention

[0006] The purpose of the present invention is to propose an in-situ preparation method for a temperature sensing electrode for a silicon-based photovoltaic cell, to provide new materials for the intelligentization of a temperature control system for a silicon-based photovoltaic cell, and to reduce blindness in research and development.

[0007] The in-situ preparation method of the temperature sensing electrode for silicon-based photovoltaic cells proposed in the present invention is characterized by: (1) Laser grooving: Using an electrodeless silicon-based photovoltaic cell as the substrate, a groove is made on the surface of the photovoltaic cell using an ultraviolet laser; wherein the size of the electrodeless silicon-based photovoltaic cell is 10 cm × 10 cm × 0.2 mm; wherein the wavelength of the ultraviolet laser is 355 nm, the grooving rate is 50 mm / s, the grooving depth is 2-4 μm, the grooving width is 40-80 μm, and the grooving length is 2-3 cm; (2) Groove cleaning: Place the electrodeless silicon-based photovoltaic cell after laser groove opening in step (1) in a hydrofluoric acid aqueous solution with a mass percentage concentration of 5-10%, leave it at room temperature for 10-15 seconds, take it out, wash it with deionized water, and blow it dry with nitrogen; (3) Catalytic activation: placing the electrodeless silicon-based photovoltaic cell cleaned in step (2) in a catalytic activation solution and soaking it at room temperature for 3-5 minutes, wherein the components and concentrations of the catalytic activation solution are as follows: palladium chloride: 0.1-0.3 g / L, nitric acid: 10-15 g / L, acetic acid: 10-15 g / L, and the balance is deionized water; (4) Chemical nickel plating: placing the electrodeless silicon-based photovoltaic cell sheet after catalytic activation in step (3) in a chemical nickel plating solution, wherein the pH value of the chemical nickel plating solution is 8-10, the plating temperature is 40-60°C, and the plating time is 10 minutes, to obtain a temperature-sensitive electrode for a silicon-based photovoltaic cell; wherein the components and concentrations in the chemical nickel plating solution are: nickel sulfate: 100-140 g / L, ammonia water: 100-120 g / L, sodium hypophosphite: 90-130 g / L, citric acid: 40-60 g / L, ammonium chloride: 30-50 g / L, and the balance is deionized water; (5) Temperature sensitivity measurement: A test platform was built using an LCR digital bridge and a heating platform to test the temperature sensing sensitivity of the temperature sensing electrode for the silicon-based photovoltaic cell prepared in step (4); wherein the heating platform provided a temperature change, the starting temperature was recorded as T0, and the test temperature was recorded as T; the LCR digital bridge recorded the resistance value of the temperature sensing electrode at a temperature of T0 as R0, and the resistance value at a temperature of T as R, and the temperature sensing sensitivity of the temperature sensing electrode was calculated as follows: (R-R0) / (R0*(T-T0)); (6) Optimizing the preparation process of the temperature sensing electrode: Taking the temperature sensing sensitivity obtained in step (5) as the response value, and taking the nickel sulfate concentration, sodium hypophosphite concentration, plating temperature, and plating solution pH as the control factors, the response surface analysis method is used to obtain the control factor-temperature sensing sensitivity correspondence algorithm and contour model, and the optimal control factor values ​​are determined to be: nickel sulfate concentration is 125 g / L, sodium hypophosphite concentration is 112 g / L, plating temperature is 51°C, and plating solution pH is 8.9; the optimal temperature sensing sensitivity of the temperature sensing electrode for silicon-based photovoltaic cells is 0.86% / °C.

[0008] The temperature sensor sensitivity (SRNC) response surface algorithm is: Wherein X1 is the nickel sulfate concentration, X2 is the sodium hypophosphite concentration, X3 is the plating temperature, and X4 is the pH value of the plating solution. The coded values ​​are used to represent the actual process parameter values ​​(see Example 6, Table 1).

[0009] The present invention has the following advantages: (1) It is compatible with the "nickel / copper / tin" non-silver grid electrode process of photovoltaic cells, and has the same silicon wafer grooving, hydrofluoric acid cleaning and chemical nickel plating process steps, which are not available in other photovoltaic temperature-sensitive electrodes. (2) The temperature-sensitive electrode is generated in situ and embedded in the groove on the silicon substrate. It has strong bonding with the photovoltaic silicon substrate and high reliability. (3) Through the response surface analysis method, a corresponding relationship model is established between the preparation process technical parameters and the temperature sensing sensitivity. The preparation technical parameters are optimized based on the algorithm to achieve the predictability of the sensing sensitivity of the photovoltaic temperature-sensitive electrode.

[0010] Patent CN202420517437.1 discloses a mounting structure of a sensor for measuring the temperature of photovoltaic cells in a photovoltaic power station, including a bottom plate, a top plate arranged above the bottom plate, a gasket fixedly connected above the bottom plate and below the top plate, a second threaded rod rotatably connected above the bottom plate, the second threaded rod and the top plate thread penetrate, a reinforcement assembly arranged above the bottom plate, the reinforcement assembly including a limit rod, the limit rod is fixedly connected to the top of the bottom plate, the limit rod is movably penetrated above the top plate, a top sheet is fixedly connected above the limit rod, a first spring is elastically connected between the top sheet and the top plate, and a support assembly is arranged on the right side of the bottom plate. When the second threaded rod is rotated, the bottom plate and the top plate clamp the edge of the photovoltaic cell. At this time, the reinforcement assembly will not only play a limiting role but also exert downward pressure on the top plate to prevent the second threaded rod from loosening and causing the clamping to loosen. This patent is different from the temperature measurement method involved in the present invention. The present invention is to prepare the temperature sensing electrode in situ on the silicon wafer of the photovoltaic cell, which does not require a complex mounting structure and is easier to operate.

[0011] Invention patent CN201711241210.X discloses a nickel resistance temperature sensor, including a protective shell, a temperature sensing component and a plug-in component. The protective shell has a cavity and one end is closed. The temperature sensing component includes a thermistor assembly and a resistance wire ring. The thermistor assembly includes a skeleton formed by stacking two mica sheets and a nickel winding formed by winding nickel alloy wire on the skeleton. The free end of the skeleton is encapsulated in the closed end of the protective shell. The resistance wire ring is connected in series with the nickel winding. The plug-in component is placed in the protective shell and installed at the fixed end of the skeleton and connected to the nickel winding. The thermistor assembly has high reliability, expands the temperature measurement range, and has stable resistance value. After the resistance wire ring is connected in series, the thermal resistivity is reduced, making the curve smoother during measurement; the thermal conductive sheet can achieve thermal stability faster and reduce vibration. Although both the invention and the present invention use nickel materials as thermistors, the material systems are different. The invention uses nickel alloys, and the present invention uses nickel thin films; the invention uses nickel alloy wire windings, and the present invention generates nickel electrodes in situ on photovoltaic silicon wafers. The two have different technical processes and different application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Optical photograph of temperature-sensing electrodes for silicon-based photovoltaic cells.

[0013] Figure 2 Atomic force microscope image of temperature-sensing electrodes for silicon-based photovoltaic cells.

[0014] Figure 3Response surface modeling contour plots: (a) Effect of nickel sulfate concentration X1 and sodium hypophosphite concentration X2 on the response value - temperature sensor sensitivity SRNC; (b) Effect of nickel sulfate concentration X1 and plating temperature X3 on the response value - temperature sensor sensitivity SRNC; (c) Effect of nickel sulfate concentration X1 and plating solution pH value X4 on the response value - temperature sensor sensitivity SRNC; (d) Effect of sodium hypophosphite concentration X2 and plating temperature X3 on the response value - temperature sensor sensitivity SRNC; (e) Effect of sodium hypophosphite concentration X2 and plating solution pH value X4 on the response value - temperature sensor sensitivity SRNC; (f) Effect of plating temperature X3 and plating solution pH value X4 on the response value - temperature sensor sensitivity SRNC. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments. Example 1

[0016] (1) Laser grooving: Using an electrodeless silicon-based photovoltaic cell as the substrate, a groove is made on the surface of the photovoltaic cell using an ultraviolet laser; the size of the electrodeless silicon-based photovoltaic cell is 10 cm × 10 cm × 0.2 mm; the wavelength of the ultraviolet laser is 355 nm, the grooving rate is 50 mm / s, the grooving depth is 2 μm, the grooving width is 40 μm, and the grooving length is 2 cm; (2) Groove cleaning: Place the electrodeless silicon-based photovoltaic cell after laser groove opening in step (1) in a 5% by mass hydrofluoric acid aqueous solution, leave it at room temperature for 10 seconds, take it out, wash it with deionized water, and blow it dry with nitrogen; (3) Catalytic activation: placing the electrodeless silicon-based photovoltaic cell washed in step (2) in a catalytic activation solution and soaking it at room temperature for 3 minutes, wherein the components and concentrations of the catalytic activation solution are as follows: palladium chloride: 0.1 g / L, nitric acid: 10 g / L, acetic acid: 10 g / L, and the balance is deionized water; (4) Chemical nickel plating: placing the electrodeless silicon-based photovoltaic cell sheet after catalytic activation in step (3) in a chemical nickel plating solution, wherein the pH value of the chemical nickel plating solution is 8, the plating temperature is 40°C, and the plating time is 10 minutes, to obtain a temperature-sensitive electrode for a silicon-based photovoltaic cell; wherein the components and concentrations in the chemical nickel plating solution are: nickel sulfate: 100 g / L, ammonia water: 100 g / L, sodium hypophosphite: 90 g / L, citric acid: 40 g / L, ammonium chloride: 30 g / L, and the remainder is deionized water; (5) Temperature sensitivity measurement: A test platform was built using an LCR digital bridge and a heating platform to test the temperature sensing sensitivity of the temperature sensing electrode for silicon-based photovoltaic cells prepared in step (4); wherein the heating platform provided temperature changes, the starting temperature was recorded as T0, and the test temperature was recorded as T; the resistance value of the temperature sensing electrode at a temperature of T0 was recorded by the LCR digital bridge as R0, and the resistance value at a temperature of T was recorded as R, and the temperature sensing sensitivity of the temperature sensing electrode was calculated as follows: (R-R0) / (R0*(T-T0)); the optimal temperature sensing sensitivity of the temperature sensing electrode for silicon-based photovoltaic cells was measured to be 0.48% / °C. Example 2

[0017] (1) Laser grooving: Using an electrodeless silicon-based photovoltaic cell as the substrate, a groove is made on the surface of the photovoltaic cell using an ultraviolet laser; the size of the electrodeless silicon-based photovoltaic cell is 10 cm × 10 cm × 0.2 mm; the wavelength of the ultraviolet laser is 355 nm, the grooving rate is 50 mm / s, the grooving depth is 4 μm, the grooving width is 80 μm, and the grooving length is 3 cm; (2) Groove cleaning: Place the electrodeless silicon-based photovoltaic cell after laser groove opening in step (1) in a 10% by mass hydrofluoric acid aqueous solution at room temperature for 15 seconds, take it out, rinse it with deionized water, and blow it dry with nitrogen; (3) Catalytic activation: placing the electrodeless silicon-based photovoltaic cell cleaned in step (2) in a catalytic activation solution and soaking it at room temperature for 3-5 minutes, wherein the components and concentrations of the catalytic activation solution are as follows: palladium chloride: 0.3 g / L, nitric acid: 15 g / L, acetic acid: 15 g / L, and the balance is deionized water; (4) Chemical nickel plating: placing the electrodeless silicon-based photovoltaic cell sheet after catalytic activation in step (3) in a chemical nickel plating solution, wherein the pH value of the chemical nickel plating solution is 10, the plating temperature is 60°C, and the plating time is 10 minutes, to obtain a temperature-sensitive electrode for a silicon-based photovoltaic cell; wherein the components and concentrations in the chemical nickel plating solution are as follows: nickel sulfate: 140 g / L, ammonia water: 120 g / L, sodium hypophosphite: 130 g / L, citric acid: 60 g / L, ammonium chloride: 50 g / L, and the remainder is deionized water; (5) Temperature sensitivity measurement: A test platform was built using an LCR digital bridge and a heating platform to test the temperature sensing sensitivity of the temperature sensing electrode for silicon-based photovoltaic cells prepared in step (4); wherein the heating platform provided temperature changes, the starting temperature was recorded as T0, and the test temperature was recorded as T; the resistance value of the temperature sensing electrode at a temperature of T0 was recorded by the LCR digital bridge as R0, and the resistance value at a temperature of T was recorded as R, and the temperature sensing sensitivity of the temperature sensing electrode was calculated as follows: (R-R0) / (R0*(T-T0)); the optimal temperature sensing sensitivity of the temperature sensing electrode for silicon-based photovoltaic cells was measured to be 0.67% / °C. Example 3

[0018] (1) Laser grooving: Using an electrodeless silicon-based photovoltaic cell as the substrate, a groove is made on the surface of the photovoltaic cell using an ultraviolet laser; the size of the electrodeless silicon-based photovoltaic cell is 10 cm × 10 cm × 0.2 mm; the wavelength of the ultraviolet laser is 355 nm, the grooving rate is 50 mm / s, the grooving depth is 3 μm, the grooving width is 60 μm, and the grooving length is 3 cm; (2) Groove cleaning: Place the electrodeless silicon-based photovoltaic cell after laser groove opening in step (1) in a hydrofluoric acid aqueous solution with a mass percentage concentration of 8%, leave it at room temperature for 13 seconds, take it out, wash it with deionized water, and blow it dry with nitrogen; (3) Catalytic activation: the electrodeless silicon-based photovoltaic cell washed in step (2) is placed in a catalytic activation solution and soaked at room temperature for 4 minutes, wherein the components and concentrations of the catalytic activation solution are as follows: palladium chloride: 0.2 g / L, nitric acid: 13 g / L, acetic acid: 13 g / L, and the balance is deionized water; (4) Chemical nickel plating: placing the electrodeless silicon-based photovoltaic cell sheet after catalytic activation in step (3) in a chemical nickel plating solution, wherein the pH value of the chemical nickel plating solution is 9, the plating temperature is 50°C, and the plating time is 10 minutes, to obtain a temperature-sensitive electrode for a silicon-based photovoltaic cell; wherein the components and concentrations in the chemical nickel plating solution are as follows: nickel sulfate: 130 g / L, ammonia water: 110 g / L, sodium hypophosphite: 110 g / L, citric acid: 50 g / L, ammonium chloride: 40 g / L, and the remainder is deionized water; (5) Temperature sensitivity measurement: A test platform was built using an LCR digital bridge and a heating platform to test the temperature sensing sensitivity of the temperature sensing electrode for silicon-based photovoltaic cells prepared in step (4); wherein the heating platform provided temperature changes, the starting temperature was recorded as T0, and the test temperature was recorded as T; the resistance value of the temperature sensing electrode at a temperature of T0 was recorded by the LCR digital bridge as R0, and the resistance value at a temperature of T was recorded as R, and the temperature sensing sensitivity of the temperature sensing electrode was calculated as follows: (R-R0) / (R0*(T-T0)); the optimal temperature sensing sensitivity of the temperature sensing electrode for silicon-based photovoltaic cells was measured to be 0.78% / °C. Example 4

[0019] (1) Laser grooving: Using an electrodeless silicon-based photovoltaic cell as the substrate, a groove is made on the surface of the photovoltaic cell using an ultraviolet laser; the size of the electrodeless silicon-based photovoltaic cell is 10 cm × 10 cm × 0.2 mm; the wavelength of the ultraviolet laser is 355 nm, the grooving rate is 50 mm / s, the grooving depth is 2 μm, the grooving width is 80 μm, and the grooving length is 2 cm; (2) Groove cleaning: Place the electrodeless silicon-based photovoltaic cell after laser groove opening in step (1) in a 5% by mass hydrofluoric acid aqueous solution at room temperature for 15 seconds, take it out, rinse it with deionized water, and blow it dry with nitrogen; (3) Catalytic activation: the electrodeless silicon-based photovoltaic cell washed in step (2) is placed in a catalytic activation solution and soaked at room temperature for 3 minutes, wherein the components and concentrations of the catalytic activation solution are as follows: palladium chloride: 0.3 g / L, nitric acid: 10 g / L, acetic acid: 15 g / L, and the balance is deionized water; (4) Chemical nickel plating: placing the electrodeless silicon-based photovoltaic cell sheet after catalytic activation in step (3) in a chemical nickel plating solution, wherein the pH value of the chemical nickel plating solution is 8, the plating temperature is 60°C, and the plating time is 10 minutes, to obtain a temperature-sensitive electrode for a silicon-based photovoltaic cell; wherein the components and concentrations in the chemical nickel plating solution are as follows: nickel sulfate: 100 g / L, ammonia water: 120 g / L, sodium hypophosphite: 90 g / L, citric acid: 60 g / L, ammonium chloride: 30 g / L, and the remainder is deionized water; (5) Temperature sensitivity measurement: A test platform was built using an LCR digital bridge and a heating platform to test the temperature sensing sensitivity of the temperature sensing electrode for silicon-based photovoltaic cells prepared in step (4); wherein the temperature change was provided by the heating platform, the starting temperature was recorded as T0, and the test temperature was recorded as T; the resistance value of the temperature sensing electrode at a temperature of T0 was recorded by the LCR digital bridge as R0, and the resistance value at a temperature of T was recorded as R, and the temperature sensing sensitivity of the temperature sensing electrode was calculated as follows: (R-R0) / (R0*(T-T0)); the optimal temperature sensing sensitivity of the temperature sensing electrode for silicon-based photovoltaic cells was measured to be 0.54% / °C. Example 5

[0020] (1) Laser grooving: Using an electrodeless silicon-based photovoltaic cell as the substrate, a groove is made on the surface of the photovoltaic cell using an ultraviolet laser; the size of the electrodeless silicon-based photovoltaic cell is 10 cm × 10 cm × 0.2 mm; the wavelength of the ultraviolet laser is 355 nm, the grooving rate is 50 mm / s, the grooving depth is 4 μm, the grooving width is 40 μm, and the grooving length is 3 cm respectively; (2) Groove cleaning: Place the electrodeless silicon-based photovoltaic cell after laser groove opening in step (1) in a 10% by mass hydrofluoric acid aqueous solution, leave it at room temperature for 10 seconds, take it out, wash it with deionized water, and blow it dry with nitrogen; (3) Catalytic activation: placing the electrodeless silicon-based photovoltaic cell cleaned in step (2) in a catalytic activation solution and soaking it at room temperature for 5 minutes, wherein the components and concentrations of the catalytic activation solution are as follows: palladium chloride: 0.1 g / L, nitric acid: 15 g / L, acetic acid: 10 g / L, and the balance is deionized water; (4) Chemical nickel plating: placing the electrodeless silicon-based photovoltaic cell sheet after catalytic activation in step (3) in a chemical nickel plating solution, wherein the pH value of the chemical nickel plating solution is 10, the plating temperature is 40°C, and the plating time is 10 minutes, to obtain a temperature-sensitive electrode for a silicon-based photovoltaic cell; wherein the components and concentrations in the chemical nickel plating solution are as follows: nickel sulfate: 140 g / L, ammonia water: 100 g / L, sodium hypophosphite: 130 g / L, citric acid: 40 g / L, ammonium chloride: 50 g / L, and the remainder is deionized water; (5) Temperature sensitivity measurement: A test platform was built using an LCR digital bridge and a heating platform to test the temperature sensing sensitivity of the temperature sensing electrode for silicon-based photovoltaic cells prepared in step (4); wherein the heating platform provided temperature changes, the starting temperature was recorded as T0, and the test temperature was recorded as T; the resistance value of the temperature sensing electrode at a temperature of T0 was recorded by the LCR digital bridge as R0, and the resistance value at a temperature of T was recorded as R, and the temperature sensing sensitivity of the temperature sensing electrode was calculated as follows: (R-R0) / (R0*(T-T0)); the optimal temperature sensing sensitivity of the temperature sensing electrode for silicon-based photovoltaic cells was measured to be 0.61% / °C. Example 6

[0021] Based on the response surface analysis method, the nickel sulfate concentration, sodium hypophosphite concentration, plating temperature and plating solution pH value are set as control factors X1, X2, X3 and X4, respectively. The influence of the interaction between the four independent factors on the temperature sensing sensitivity of the temperature sensing electrode is analyzed, and the optimal parameters under this process condition are obtained. Combined with Examples 1-5, the four independent factors and the corresponding parameter ranges are shown in Table 1.

[0022]

[0023] The temperature sensor sensitivity (SRNC) response surface algorithm is: Where X1 is the nickel sulfate concentration, X2 is the sodium hypophosphite concentration, X3 is the plating temperature, and X4 is the pH value of the plating solution. The coded value is used to represent the actual process parameter value.

[0024] The contour map obtained by the response surface algorithm is shown in the attached figure. Figure 3 shown.

[0025] Attached Figure 3 The contour lines in (a), (b), and (c) respectively show the effects of the interaction between nickel sulfate concentration and sodium hypophosphite concentration, plating temperature, and plating solution pH on the temperature sensor sensitivity. The temperature sensor sensitivity first decreases and then increases with the increase of nickel sulfate concentration, and the optimal response value is fixed at 125 g / L. Attached Figure 3The contour lines in (a), (d), and (e) respectively show the effects of the interaction between sodium hypophosphite concentration and nickel sulfate concentration, plating temperature, and plating solution pH on the temperature sensing sensitivity. The temperature sensing sensitivity generally decreases first and then increases with the increase of sodium hypophosphite concentration, and the optimal response value is fixed at 112 g / L.

[0026] Attached Figure 3 The contour maps in (b), (d), and (f) respectively show the effects of the pairwise interactions between the plating temperature and the nickel sulfate concentration, sodium hypophosphite concentration, and the pH of the plating solution on the temperature sensor sensitivity. The temperature sensor sensitivity first decreases and then increases with the increase of the plating temperature, and the optimal response value is fixed at 51°C.

[0027] Attached Figure 3 (c), (e), and (f) illustrate the effects of the pairwise interactions between the pH value of the plating solution and the nickel sulfate concentration, sodium hypophosphite concentration, and plating temperature on the temperature sensor sensitivity. The temperature sensor sensitivity first decreases and then increases with the increase of the pH value of the plating solution, and the optimal response value is fixed at 8.9.

[0028] Therefore, the optimal process parameters are: nickel sulfate concentration is 125g / L, sodium hypophosphite concentration is 112g / L, plating temperature is 51℃, and plating solution pH is 8.9; the model prediction value and actual experimental value of the response surface model under the optimal process parameter conditions are shown in Table 2.

[0029] The experimental verification process is as follows: (1) Laser grooving: Using an electrodeless silicon-based photovoltaic cell as the substrate, a groove is made on the surface of the photovoltaic cell using an ultraviolet laser; the size of the electrodeless silicon-based photovoltaic cell is 10 cm × 10 cm × 0.2 mm; the wavelength of the ultraviolet laser is 355 nm, the grooving rate is 50 mm / s, the grooving depth is 3 μm, the grooving width is 60 μm, and the grooving length is 3 cm; (2) Groove cleaning: Place the electrodeless silicon-based photovoltaic cell after laser groove opening in step (1) in a hydrofluoric acid aqueous solution with a mass percentage concentration of 8%, leave it at room temperature for 13 seconds, take it out, wash it with deionized water, and blow it dry with nitrogen; (3) Catalytic activation: the electrodeless silicon-based photovoltaic cell washed in step (2) is placed in a catalytic activation solution and soaked at room temperature for 4 minutes, wherein the components and concentrations of the catalytic activation solution are as follows: palladium chloride: 0.2 g / L, nitric acid: 13 g / L, acetic acid: 13 g / L, and the balance is deionized water; (4) Chemical nickel plating: placing the electrodeless silicon-based photovoltaic cell after catalytic activation in step (3) in a chemical nickel plating solution, wherein the pH value of the chemical nickel plating solution is 8.9, the plating temperature is 51°C, and the plating time is 10 minutes, to obtain a temperature-sensitive electrode for a silicon-based photovoltaic cell; wherein the components and concentrations in the chemical nickel plating solution are as follows: nickel sulfate: 125 g / L, ammonia water: 110 g / L, sodium hypophosphite: 112 g / L, citric acid: 50 g / L, ammonium chloride: 40 g / L, and the remainder is deionized water; (5) Temperature sensitivity measurement: A test platform was built using an LCR digital bridge and a heating platform to test the temperature sensing sensitivity of the temperature sensing electrode for silicon-based photovoltaic cells prepared in step (4); wherein the heating platform provided temperature changes, the starting temperature was recorded as T0, and the test temperature was recorded as T; the resistance value of the temperature sensing electrode at a temperature of T0 was recorded by the LCR digital bridge as R0, and the resistance value at a temperature of T was recorded as R, and the temperature sensing sensitivity of the temperature sensing electrode was calculated as follows: (R-R0) / (R0*(T-T0)); the optimal temperature sensing sensitivity of the temperature sensing electrode for silicon-based photovoltaic cells was measured to be 0.86% / °C.

Claims

1. An in-situ preparation method for a temperature sensing electrode for a silicon-based photovoltaic cell, characterized in that: (1) Laser grooving: Using an electrodeless silicon-based photovoltaic cell as the substrate, a groove is made on the surface of the photovoltaic cell using an ultraviolet laser; the size of the electrodeless silicon-based photovoltaic cell is 10 cm×10 cm×0.2 mm; the wavelength of the ultraviolet laser is 355 nm, the grooving rate is 50 mm / s, the grooving depth is 2-4 μm, the grooving width is 40-80 μm, and the grooving length is 2-3 cm; (2) Groove cleaning: Place the electrodeless silicon-based photovoltaic cell after laser groove opening in step (1) in a hydrofluoric acid aqueous solution with a mass percentage concentration of 5-10%, leave it at room temperature for 10-15 seconds, take it out, wash it with deionized water, and blow it dry with nitrogen; (3) Catalytic activation: placing the electrodeless silicon-based photovoltaic cell cleaned in step (2) in a catalytic activation solution and soaking it at room temperature for 3-5 minutes, wherein the components and concentrations of the catalytic activation solution are as follows: palladium chloride: 0.1-0.3 g / L, nitric acid: 10-15 g / L, acetic acid: 10-15 g / L, and the balance is deionized water; (4) Chemical nickel plating: placing the electrodeless silicon-based photovoltaic cell sheet after catalytic activation in step (3) in a chemical nickel plating solution, wherein the pH value of the chemical nickel plating solution is 8-10, the plating temperature is 40-60°C, and the plating time is 10 minutes, to obtain a temperature-sensitive electrode for a silicon-based photovoltaic cell; wherein the components and concentrations in the chemical nickel plating solution are: nickel sulfate: 100-140 g / L, ammonia water: 100-120 g / L, sodium hypophosphite: 90-130 g / L, citric acid: 40-60 g / L, ammonium chloride: 30-50 g / L, and the balance is deionized water; (5) Temperature sensitivity measurement: A test platform was built using an LCR digital bridge and a heating platform to test the temperature sensing sensitivity of the temperature sensing electrode for the silicon-based photovoltaic cell prepared in step (4); wherein the heating platform provided a temperature change, the starting temperature was recorded as T0, and the test temperature was recorded as T; the LCR digital bridge recorded the resistance value of the temperature sensing electrode at a temperature of T0 as R0, and the resistance value at a temperature of T as R, and the temperature sensing sensitivity of the temperature sensing electrode was calculated as follows: (R-R0) / (R0*(T-T0)); (6) Optimizing the preparation process of the temperature sensing electrode: Taking the temperature sensing sensitivity obtained in step (5) as the response value, and taking the nickel sulfate concentration, sodium hypophosphite concentration, plating temperature, and plating solution pH as the control factors, the response surface analysis method was used to obtain the control factor-temperature sensing sensitivity correspondence algorithm and contour map, and the optimal control factor values ​​were determined to be: nickel sulfate concentration of 125 g / L, sodium hypophosphite concentration of 112 g / L, plating temperature of 51°C, and plating solution pH of 8.9; the optimal temperature sensing sensitivity of the temperature sensing electrode for silicon-based photovoltaic cells is 0.86% / °C.

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