Band-gap shifts in heavily dopedn-type GaAs

Abstract

We present theoretical results for the band-gap shifts in heavily doped n-type GaAs. We find that the bands are far from being shifted rigidly. The states at the band edges are shifted more than the states with Fermi momentum. Consequently, the band-gap narrowing deduced from absorption experiments is strongly underestimated. Our results are compared to those from experiments on photoluminescence, cathodoluminescence, and diode-injection luminescence and from absorption measurements. Agreement is found with all the experimental results and we give a new explanation for the position of the luminescence peak in the diode-injection experiments and its shift with varying forward bias voltage.