Corrections to the Fermi level in heavily doped GaAs

Abstract

The correction to the chemical potential of a high-density electron gas due to the presence of charged impurities is calculated using Green's-function techniques. In first order, a ${r_s}^{-\frac{1}{2}}$ correction is determined as compared to the ${r_s}^{-\frac{1}{3}}$ correction previously determined by Bonch-Breuvich and Zyagin. In either case, however, the contribution is small compared to the contributions from electron exchange and correlation. The upward shift in the Fermi level as a function of impurity concentration is contrasted with optical experiments of Hill on heavily doped GaAs. A discrepancy is noted between experiment and theory.