Limitations to the open circuit voltage of amorphous silicon solar cells

Abstract

In this paper, we investigate the open circuit voltage of amorphous silicon alloy p-i-n and n-i-p solar cells and show that the low open circuit voltage of some devices can be caused by a built-in potential smaller than normal arising from a low band-gap p+ layer. For these solar cells, in good agreement with experimental data, the introduction of a boron profile in 200-500 Å of the intrinsic region near the p+-i interface can enhance the open circuit voltage by about 150-200 mV to a value close to the bulk recombination limit.