Depletion region recombination in silicon thin-film multilayer solar cells

Abstract

A parallel multijunction approach appears promising as a way of producing high-performance polycrystalline thin-film silicon solar cells by deposition onto inexpensive glass superstrates. Recent independent analyses have confirmed some of the claimed advantages for this approach. However, both the size of likely advantages and the domain of parameter space over which they prevail have been underestimated in many cases. This is due to a failure to incorporate an essential design feature: tailoring of junction properties to minimize junction recombination. It is shown that insertion of thin intrinsic regions between the doped layers of the multilayer stack can reduce junction recombination significantly, by a factor of over 800 000 from values calculated in one recent study.