Mechanism And Experimental Study Of Laser Cladding Boron Doped Nanometer Silicon Slurry

In order to solve the problems of low carrier concentration,shallow junction depth and high void ratio in the local Al back field of traditional PERC solar cells,the process of nanosecond laser cladding a heavily doped boron nano-silicon slurry on the solar silicon substrate was studied.The process was compatible with the production line of PERC solar cells to prepare the local Al-B back field,and the Al-B back field was analyzed.The effect of electric field on the performance of batteries.The main contents of this paper are as follows:(1)Using heavily doped P-type single crystal silicon as raw material,nano-silicon particles with particle size(D50)less than 80 nm were prepared by pulse discharge and high energy ball milling combined process,and silicon slurry was prepared by fully mixing silicon particles with organic carriers.the optimum formula of organic carrier was determined.Silicon slurry has good printing performance to achieve the accurate transfer of patterns in the printing process;(2)Considering the light absorption mechanism of semiconductor silicon materials,the properties of silicon materials with temperature,latent heat,heat source and boundary conditions,the temperature field distribution of laser cladding nano-silicon slurry under nanosecond and picosecond pulse widths was studied by using Fourier heat transfer equation and two-temperature equation respectively,and the laser under nanosecond laser was also studied by single factor simulation experiment.The influence of power,scanning speed and repetition frequency on the highest temperature of molten pool,the highest temperature of matrix material and the area of molten pool;(3)The orthogonal experiment was used to optimize the process parameters of nanosecond laser cladding.The results show that the cladding layer has the best surface morphology,cross-section structure and production efficiency when the laser power is 26 W,the scanning speed is 16 m/s and the repetition frequency is 350 kHz;(4)The nanosecond laser cladding process is compatible with PERC battery production process for battery test.Different processes are used to compare and analyze the efficiency of the experimental group and the control group.The results show that the average efficiency of the experimental group is 21.65%,the efficiency is increased by 0.12%.