Electronic properties of semiconductors with negative-U centers

Abstract

The concentration of free charge carriers p as a function of the doping level C [p(C) characteristic] is calculated for a semiconductor containing defects with negative correlation energy U of bound charge carrier pairs. It is shown that in a certain interval pC12 in contrast to the behavior of defects with positive correlation energy U and of singly charged defects. Therefore, one has a simple criterion to prove experimentally whether a given kind of defect level has the negative-U property or not. © 1980 The American Physical Society.