Measurement of the In_0.52Al_0.48As valence-band hydrostatic deformation potential and the hydrostatic-pressure dependence of the In_0.52Al_0.48As/InP valence-band offset

We have measured the In_0.52Al_0.48As valence-band hydrostatic deformation potential from the hydrostatic-pressure dependence of the In_0.52Al_0.48As/InP valence-band offset which was measured from 0 to 35 kbar at room temperature. Due to the type-II band lineup, the radiative recombinations across the InP band gap and between the InP conduction band and the In_0.52Al_0.48As valence band were both observed in the photoluminescence spectra. This enables us to measure directly the changes of the valence-band offset under pressure. The hydrostatic-pressure derivative of the valence-band offset was measured to be 0.0±0.4 meV/kbar. The predictions of the pressure dependence from band-offset models (dielectric midgap and model-solid theories) agree with the measurement to within 1 meV/kbar. The In_0.52Al_0.48As valence-band hydrostatic deformation potential is found to be -0.8 eV which compares well with the dielectric midgap theory. Using the reported pressure dependence of the GaAs/AlAs valence-band offset, the valence-band hydrostatic deformation potentials of In_xAl_1-xAs (0≤x≤0.52) are linearly interpolated as -1.9x+0.2 eV.