Conductance Anomalies due to Space-Charge-Induced Localized States

Abstract

Space-charge-induced accumulation regions in semiconductors and semimetals can lead to localized, discretely spaced two-dimensional energy bands for which the existence criteria and the eigenvalue spectrum are derived. The contribution of these states to the conductance of a planar metal-oxide-semimetal (-semiconductor) tunnel junction exhibits structure associated with the critical points in the density of states for motion parallel to the junction. As an example, numerical results are given for Al-oxide-Bi junctions.