多晶PERC太阳电池的背面与正面结构性能优化

多晶硅太阳电池以其价格低廉的优势成为低成本太阳电池的首选,但其光电转换效率提升空间有限。钝化发射极和背面电池（PERC）技术是当前晶硅太阳电池提效的主要途径。多晶PERC电池结合了多晶硅电池的低成本和PERC电池的高效,是当前多晶硅电池的研究热点。本文研究了多晶PERC电池的背面和正面结构优化与设计,提出了提高多晶PERC电池效率的产业化技术方法。通过在硅片背面用三层SiN_x:H薄膜来代替常规双层SiN_x:H薄膜,在保证优良的背面钝化的同时,使电池长波响应得到改善,电池光电转换效率由20.19% 提升至20.26%。优化多晶PERC电池的背面激光开窗工艺,使多晶电池效率较常规工艺提升0.11%。而在多晶PERC电池的正面叠加选择性发射极技术,可较常规工艺提升电池效率0.10%。综合运用多种提效手段有利于保持多晶PERC电池的竞争力。

Optimization of the Structure and Performance of Back and Front of Multicrystalline Si PERC Solar Cells

The multicrystalline silicon (mc-Si) solar cells have become the first choice of low-cost solar cells due to their low price, while the room for improving their photoelectric conversion efficiency is limited. Passivated emitter and rear cell (PERC) is the main technology for improving the efficiency of Si solar cells. Combing the low cost of mc-Si solar cells and high efficiency of PERC, the mc-Si PERC is paid more attention recently. A series of technologies based on the back and front structures optimization of mc-Si PERCs were studied for high efficiency and mass production in the present work. By employing layers of AlO_x/triple-SiN_x:H on the rear of mc-Si wafers, the long wavelength spectral response was strengthened while the rear surface passivation was keeping, and the average efficiency of PERC with AlO_x/triple-SiN_x:H layers was increased to 20.26% from the standard mc-Si PERC of 20.19%. The efficiency of the battery was improved by 0.11% through optimizing the rear electrode contacting patterns by laser ablation, compared with the standard mc-Si PERC. The efficiency increased by 0.10% when introducing selective emitter technology on the front of mc-Si PERC. The comprehensive applications of different methods for improving efficiency benefit to the competitiveness of mc-Si PERC.