Luminescence above the gap in heavily Zn-doped GaAs

Several distinct features have been observed in the photoluminescence spectrum of heavily Zn-doped GaAs, in the range between 1.65eV to 2.25eV. They are attributed to direct recombination across the E_o+?_o gap and to indirect processes related to X^c₁ and X^c₃. The X^c₁ minima are thus located to be 1.935±0.01eV above the top of the valence band at 100K. Their shear deformation potential $\text{E}$^X₂ is found to be $\text{E}{}^{\mathrm{X}}{}_2\text{=5.5±2eV}$.