The effect of hydrostatic pressure on the 0.15 eV Cu acceptor level in GaAs

Abstract

The evolution of the characteristic photoluminescence (PL) of the 0.15 eV Cu acceptor level in GaAs has been studied as a function of hydrostatic pressure. In the pressure range up to 35 kbar, i.e. in the direct gap region, the Cu-related PL band closely tracks the near-band-edge emission. The pressure derivative of the Cu acceptor level has been determined and is found to be 0.3 ± 0.2 meV/kbar. This number is only a small fraction of the total pressure derivative of the Γ 1C− Γ 15V energy gap which amounts to 10.7 meV/kbar, a result similar to our previous findings for the Mn acceptor level in GaAs, for which the pressure derivative was found to be 1.2 ± 0.2 meV/kbar. It should be noted that the remaining difference in pressure derivative is significant and beyond the uncertainty of the experimental data.