Strongly quenched deformation potentials of the Mn acceptor in GaAs

Abstract

We have measured the luminescence spectrum of Mn-doped GaAs at liquid-He temperatures with and without an applied uniaxial stress. At zero stress we found clearly resolved donor-acceptor (DA) and band-acceptor recombination bands involving Mn. From these measurements we get a precise acceptor binding energy of 113 ± 0.5 meV. The stress dependence of the peak energy and of the polarization of the DA recombination spectrum was used to derive the following deformation potentials of the acceptor: $a^{\prime }=-9.1\mathrm{}$ eV, $b^{\prime }=-0.35\mathrm{}$ eV, and $d^{\prime }=-0.8\mathrm{}$ eV. The potentials $b^{\prime }$ and $d^{\prime }$ are only 18% and 15%, respectively, of the corresponding shear-strain-deformation potentials of the valence band. We attribute this reduction principally to the localization of the bound hole with an additional contribution from a dynamic Jahn-Teller effect.