BAND DISCONTINUITIES AT HETEROJUNCTIONS BETWEEN CRYSTALLINE AND AMORPHOUS-SILICON

We present a theoretical investigation of the band lineups between cry stalline and amorphous silicon, based on the first-principles pseudopo tential method and the model-solid theory. We find that the offsets ar e very sensitive to the hydrogen content of the material; the valence- band offset for a junction with unhydrogenated a-Si is -0.25 eV, while for hydrogenated a-Si with a hydrogen content of 11% the offset becom es 0.20 eV. Consequences for the interpretation of experimental data a re discussed. (C) 1995 American Vacuum Society.