Abstract:Two surface processing methods, which includes depositing SiNx thin film on the cells and annealing the cells inH2, were carried out on low-cost multi-crystalline silicon solar cells. The efficiency of the solar cells was tested before and after the surface processing. And the effects of the two surface processing methods on the short-circuit current, open-circuit voltage, fill factor and efficiency were carried out in this paper. The results show that the efficiency of the low-cost solar cells is improved by 1.8% after depositing SiNx thin film on the cells, but after H2 annealing, the efficiency is degraded. And high-cost solar-graded multi-crystalline silicon solar cells are also annealed in H2 atmosphere, but its efficiency increases, which shows different tendency compared to low-cost multi-crystalline silicon solar cells. Finally the factors resulting in different effects by the two methods are analyzed and discussed.