Photoluminescence spectroscopy of many-body effects in heavily doped AlxGa1−xAs

Abstract

We present an experimental investigation of heavy doping-induced many-body effects such as band gap narrowing and Fermi-edge singularity (FES) in AlxGa1−xAs using photoluminescence (PL) spectroscopy. The band-to-band transition energy shifts to lower energies and the FES feature in PL spectra grows with increasing electron concentration. We show that the FES feature is a nonmonotonic function of temperature and excitation intensity. Our data lead us to suggest that a small concentration of nonequilibrated holes is required to enhance the FES feature in the PL spectra.