基于激光掺杂的SE+PERC单晶硅太阳电池关键工艺的研究

STUDY ON KEY PROCESSES OF SE+PERC MONOCRYSTALLINE SILICON SOLAR CELLS BASED ON LASER DOPING

在现阶段主流太阳电池生产设备的水平条件下,研究了激光频率、初始方块电阻和烧结峰值温度对基于激光掺杂的选择性发射极(SE)+PERC单晶硅太阳电池电性能的影响。分别采用奥林巴斯显微镜和Halm电学性能测试仪,分析了不同频率的激光在硅片表面形成的光斑形貌,以及不同实验条件时电池的电性能变化趋势。结果表明,激光频率为220 kHz时有利于在硅片表面形成连续性且不重叠的光斑,形成最佳重掺杂区,从而提升电池转换效率;基于现有的常压扩散设备的掺杂水平,在确保硅片表面方块电阻均匀性的情况下,初始方块电阻选择120Ω/□更有利于提升电池的转换效率;烧结峰值温度为790℃时,更有利于在电池电极位置形成良好的欧姆接触,从而获得最佳的电池转换效率。

The effects of laser frequency,initial square resistance and peak temperature of sintering process on SE+PERC monocrystalline silicon solar cells were studied under the current mainstream solar cell equipment level.Using Olympus microscope and Halm electrical performance tester,the morphology of light spots formed by different laser frequency on silicon wafer surface and the variation trend of electrical performance of solar cell under different experimental conditions were analyzed.The results show that the laser frequency of 220 kHz is conducive to form a continuous and non-overlapping light spot on silicon wafer surface,resulting in the formation of the best heavily doped area and the improvement of the solar cell efficiency.Based on existing cell atmospheric diffusion equipment level of doping,the highest conversion efficiency of the solar cell is obtained when the uniformity of the square resistance is optimized and the initial square resistance is 120Ω/□.When the sintering peak temperature is 790℃,a good ohmic contact can be formed and the best conversion efficiency of the solar cell can be realized.