Suppression of boron-oxygen defects in p-type Czochralski silicon by germanium doping

We have demonstrated the impact of germanium (Ge) doping on the boron-oxygen (B-O) defects in p-type Czochralski (CZ) silicon. It is found that germanium can effectively suppress the formation of B-O defects, whereby the reduction percentage of B-O defect concentration increases with the Ge content. The efficiency of Ge-doped CZ silicon solar cell and the power output of corresponding module both exhibit a significantly lower loss. Based on the fact of a relatively lower concentration of O-2i existing in GCZ silicon, it is believed that the suppression of B-O defects is a result of Ge improving the diffusion barrier of O-i. (C) 2010 American Institute of Physics. [doi:10.1063/1.3475486]