CONDUCTION-BAND TAILING IN PARABOLIC BAND SEMICONDUCTORS

Kane's [Phys. Rev. 131, 79 (1963)] model for the density of states for energies in the band gap is in qualitative agreement with experiment. Halperin and Lax [Phys. Rev. 148, 722 (1966)] have also suggested a m odel for band tailing, which is applicable to the deep tailing states. In the present study, theoretical models have been proposed for the b and tailing in the case of heavily doped semiconductors that are more general than those of Kane and others. In addition, the present study also offers an E-(k) over bar dispersion relation for band tails in th e parabolic band based on Kane's semiclassical theory. This study has helped us to obtain a different model for the density of states in the band-tailing conditions and the model is expected to agree better wit h experiment. (C) 1997 American Institute of Physics.