Electronic transport in mind model solar cells: collection efficiency in the presence of a-Si/c-Si heterointerfaces

A continuous amorphized a-Si substructure with sharp a-Si/c-Si heterointerfaces has been inserted in a c-Si wafer by P ion implantation followed by a thermal treatment at 500/spl deg/C. A simulation of the band structure taking into account the differences between the two Si phases of the MIND (multi-interface novel device) model solar cell indicates the presence of a high potential barrier blocking the minority carriers generated in the superficial region of the wafer. Consequently, the collection efficiency is deteriorated in the UV. A theoretical and experimental analysis of the causes and results of such a deterioration on the photocurrent is presented.