Band-gap narrowing in highly doped <i>n</i>- and <i>p</i>-type GaAs studied by photoluminescence spectroscopy

Abstract

Band-gap narrowing of GaAs as a function of doping concentration has been measured using photoluminescence spectroscopy on samples grown by molecular beam epitaxy. Both n- (Si) and p- (Be) doped samples with concentrations varying from 3×1017 to 3×1018 cm−3 have been measured. The experimental results obtained from a line-shape analysis of the spectra taking tailing effects into account are in good agreement with recent theoretical calculations. A simple expression for the band-gap narrowing as a function of concentration for both n-and p-doped GaAs is given.