ELECTRICAL AND OPTICAL PROPERTIES OF III-V COMPOUND SEMICONDUCTORS AT HIGH PRESSURES.

The high electric field properties of InP have been studied as a function of pressure to 55 kbar. The measured threshold field for transferred electron instability showed an initial increase with pressure, and after passing through a maximum at 30-33 kbar it decreased gradually. Monte Carlo calculations based on a stronger GAMMA -L scattering assumption seemed to agree better with the experimental data. Photoluminescence (PL) and optical absorption measurements on the heavily doped GaAs have been made as a function of pressure to 60 kbar at 77 K. With increasing pressure the spectrum shifted towards the higher energy side. The pressure dependence of the emission peak across the direct gap showed a noticeable change in slope at about 30 kbar. For pressures above 35 kbar the PL intensity suddenly decreased. The observed behavior can be explained in terms of the effect of high doping on the inversion of the GAMMA and X conduction bands at high pressure.