Density of states in heavily doped strongly compensated semiconductors with correlated impurity distribution

Abstract

To study the behavior of an electron in a heavily doped semiconductors with strong compensation using the Feynman path integral method developed by Sa-yakanit for treating the heavily doped semiconductors. The correlation function of this system is taken from Galpern and Efros. The density of states of the band tail, the kinetic energy of localization as well as the critical exponent are calculated analytically. Numerical results are also presented. Due to the compensation, the critical exponent varies from 1 to 2 instead of from 1/2 to 2 as in the case of heavily doped semiconductors. We point out that this behavior is resemble to the Urbach tail problem where the impurities approach the atomic scale.