Energy Conversion Process of p-i-n Amorphous Si Solar Cells

Abstract
The photovoltaic conversion process of a p-i-n amorphous silicon (a-Si) solar cell is investigated, and its theoretical limit efficiency is calculated. Under AM-1 illumination, the theoretical limit efficiency of the p-i-n a-Si solar cell is estimated to be 12.5%, while that under fluorescent lamp illumination is estimated to be 25.9%. In the calculation of the charge distribution in a-Si film, the “Shifted U” distribution is proposed for the distribution function of gap states. Poisson's equation is directly solved as a boundary condition problem, and then the output characteristics of the p-i-n a-Si solar cell are claculated by solving the continuity equation for the photo-generated carriers.