密栅线n型TOPCon单晶硅太阳电池的量产工艺及电性能研究OA

The high diffusion concentration and severe carrier recombination on the surface of n-TOPCon mono-Si solar cells make it difficult to improve their photoelectric conversion efficiency.However,the dense finger line process is one of the important ways to improve the photoelectric conversion efficiency of n-TOPCon mono-Si solar cells,but its difficulties lie in the compatibility of diffusion resistance of the silicon wafer,screen parameters and peak sintering process with such solar cells.Based on this,this paper takes the mass production of n-TOPCon mono-Si solar cells(hereinafter referred to as TOPCon solar cells)using dense finger line technology as the research object,under the current mainstream production equipment conditions of TOPCon solar cells,the effects of silicon wafer diffusion resistance,screen parameters,and peak sintering temperature on the electrical performance of such solar cells using dense finger line technology are studied through experiments,and the optimal mass production process conditions are obtained.The research results show that:1)As the diffusion sheet resistance of silicon wafer increases,their minority carrier lifetime also gradually increases.When the diffusion sheet resistance of silicon wafer is 200 Ω/□,its minority carrier lifetime reaches its maximum of 1456 μs.2)The short-circuit current and open circuit voltage of TOPCon solar cells are positively correlated with the diffusion sheet resistance of silicon wafer,while the filling factor is negatively correlated with the diffusion sheet resistance of silicon wafer.When the diffusion sheet resistance of silicon wafer is between 160～200 Ω/□,the photoelectric conversion efficiency of TOPCon solar cells shows a trend of first increasing and then decreasing,and reaches its highest value when the diffusion sheet resistance of silicon wafer is 180 Ω/□.3)During the screen printing process,the total thickness of the screen(film thickness+yarn thickness)is gradually reduced,and combined with the narrowing of the screen width,the front finger line width and silver paste consumption of TOPCon solar cells are reduced.And as the width of the front finger line and the consumption of silver paste gradually decrease,the photoelectric conversion efficiency of TOPCon solar cell shows a trend of first increasing and then decreasing.The optimal screen parameters are a screen film thickness of 5.0 μm,a screen yarn thickness of 9.5 μm,and a screen width of 10.5 μm.4)When using the dense finger line process,the diffusion sheet resistance of silicon wafer is 180 Ω/□,the screen film thickness is 5.0 μm,the screen yarn thickness is 9.5 μm,the screen width is 10.5 μm during screen printing,and the peak sintering temperature during sintering is 790℃,which is the optimal mass production process condition of TOPCon solar cell.The corresponding TOPCon solar cell has the best photoelectric conversion efficiency,which is 26.42%.