Korte, L.; Schmidt, M.: Doping type and thickness dependence of band offsets at the amorphous/crystalline silicon heterojunction. Journal of Applied Physics 109 (2011), p. 063714/1-6
10.1063/1.3559296
Abstract:
We conduct a systematic investigation of the valence band offset DEv for amorphous/crystalline silicon heterojunctions (a-Si:H/c-Si) using low energy photoelectron spectroscopy in the constant final state mode. The dependence of DEv on a-Si:H thickness as well as on the possible combinations of c-Si substrate and a-Si:H film doping types are explored. DEv is found to be independent of both substrate and film doping and amounts to DEv=0.458(6)eV, averaged over all doping combinations and thicknesses, with a systematic error of 50-60 meV. A slight but statistically significant dependency of DEv on the a-Si:H film thickness may be explained by a changing interface dipole due to variations in dangling bond saturation during a-Si:H growth.