THE PRESSURE-DEPENDENCE OF THE BAND OFFSETS IN A GAINAS/INP MULTIPLE QUANTUM WELL STRUCTURE

The photoluminescence of a GaInAs/InP quantum well structure grown by MOCVD has been measured up to 70 kbar using a miniature cryogenic diamond anvil cell. Together with measurements of the bulk material, these data determine the pressure dependence of the confinement energies. It is found that the confinement energies decrease with pressure, and that the effect is more marked in narrow wells. In order to explain these results in terms of the pressure dependence of the barrier heights, effective masses, and well widths, it is found necessary to include a pressure dependence of the band offset. We find that the valence band offset is virtually independent of pressure while the conduction band offset decreases by approximately 2.3±0.6 Mev/kbar. This is approximately the difference in pressure coefficients of the direct band-gaps of GaInAs and InP.