TUNNELING THROUGH A NARROW-GAP SEMICONDUCTOR WITH DIFFERENT CONDUCTION-BAND AND VALENCE-BAND EFFECTIVE MASSES

We have calculated tunneling conductance in metal-narrow-gap-semicondu ctor (NGS)-metal tunnel junctions. Flietner's two-band model is used t o describe the dispersion relation within the energy gap in an isotrop ic NGS with different conduction- and valence-band edge effective mass es. The results are compared with the tunneling conductance calculated by Kane's two-band model, which has been commonly used to describe th e tunneling characteristics through the energy gap in semiconductors. These results propose that the tunneling conductance in the tunnel jun ctions in which a narrow gap semiconductor of largely different conduc tion- and valence-band effective masses is used as a tunneling barrier can exhibit quite a different behavior, especially in the region of t he midgap, from the tunneling conductance described by Kane's two-band model. (C) 1996 American Institute of Physics.