Effects of TCO/a-Si:C:H Interface Defect States on p-i-n a-Si:H Solar Cell Performance

Abstract

ABSTRACTTo explain realistic circumstances with regard to energy band profiles at the TCO/a-Si:C:H heterojunction, the ASPIN computer simulation has been used. Numerical calculations indicate that the increased interface defect densities result in a steep potential drop inside the interface region, while the rest of the work function difference extends into the p-layer. The detrimental effect of a-Si:C:H partial oxidation has been simulated by additionally increased density of states at a-Si:C:H surface, and its influence on the potential barrier has been analyzed. The impact of both TCO/a-Si:C:H interface states and a-Si:C:H surface states on the photoelectric properties of p-i-n a-Si:H solar cell is discussed, and a possible improvement of Voc is envisaged.