Effect of phosphorus diffusion to the recombination at the Si-SiO ₂ interface

Measurements of the excess carrier lifetime of diffused and undiffused, thermally oxidized silicon samples are used to show that the presence of a phosphorus diffusion results in a modification of the interface defect properties, resulting in significantly higher surface recombination velocity compared to undiffused samples. In addition, for undiffused samples, positive and negative charges are demonstrated to be equally effective at passivating the silicon surface. Both results hold for (100) and (111) oriented samples, as well as for samples subjected to various post-oxidation treatments. The results may have practical implications particularly for the design of rear contacted solar cells.