Influences of Phosphorous Gettering on Minority Carrier Lifetime Distribution of Polycrystalline Silicon Wafer

Abstract

The influences of the phosphorus gettering in PN junction formation on the distribution of minority carrier lifetime of polycrystalline silicon wafer in solar cell production process were studied. The experimental results shows that the distribution of internal defects and impurities in polycrystalline silicon wafer significantly impact on the effectiveness of the phosphorus gettering during preparation of PN junction through the phosphorus diffusion technology. Especially when the impurities were transition metal elements, it caused a large difference of the phosphorus gettering effectiveness in PN junction preparation, which was due to the presence and interaction of defects and impurities on polycrystalline silicon wafer, such as grain boundaries, dislocations, oxygen and carbon, and other metal elements. In addition, the uneven distribution of impurities and defects of also influenced the phosphorus gettering effectiveness.