Directional resolution of the GaAs heavy-hole band dispersion and photoelectron-momentum orientation from hot-electron luminescence.

Abstract

It is demonstrated how the heavy-hole dispersion of bulk GaAs can be obtained along specific high-symmetry directions from hot-electron to neutral acceptor photoluminescence spectroscopy. This is done by analyzing the degree of linear polarization in terms of a detailed line-shape calculation to identify that part of the emission which is due to carriers with a particular wave-vector direction. A systematic plot of ${\mathit{E}}_{\mathit{h}}$(k) with sub-meV accuracy is thus made possible over a range of wave vectors in the central \ensuremath{\Gamma} valleys of direct-gap semiconductors. This method exploits the hot-electron momentum orientation by linearly polarized light, which is systematically investigated, together with the extent to which such momentum orientation persists in a hot-electron population either after one-phonon emission or when it is subjected to significant carrier-carrier scattering.