Interface recombination in heterojunctions of amorphous and crystalline silicon

Heterojunction solar cells consisting of an n-type a-Si:H(n) emitter and a p-type monocrystalline silicon wafer have been studied with particular emphasis on the role of interface recombination. It is shown that the form of the I–V characteristics and the effective interface recombination velocity depend on the treatment of the Si-wafer prior to the deposition of the amorphous emitter. Numerical simulation suggests that the non-exponential (S-shape) dependence of the I–V curves under illumination arises from a high density of interface states which results in enhanced recombination via interface states.