The influence of interface state and energy barriers on the efficiency of heterojunction solar cells

Abstract

A heterojunction solar cell, in which interface recombination and arbitrary energy barriers at the interface occur, is analysed to find the optimum structure. Thermionic emission theory is used; it is assumed that one type of carriers are majority carriers at the interface and that their concentration can be known a priori. It is shown that these assumptions do not seriously limit the applicability of the theory. The results are discussed in the case when one semiconductor is much more heavily doped than the other, which is a condition that certainly improves the efficiency of the solar cell.