Electrical properties of InAs to very high pressures

Hall effect measurements to 90 kbar at 295 K on two single crystals of InAs are described. The zincblende to rock salt structure phase transition was at 69+or-2 kbar, and the high pressure phase was metallic. In the zincblende phase, results gave limiting values of E(L1c- Gamma 1c)>or=0.40 eV and E(X1c- Gamma 1c)>or=0.75 eV for the sub-band energy gaps in the conduction band. Two impurity levels situated 0.70 and 0.61 eV above the valence band maximum at atmospheric pressure were observed with pressure coefficients of 0+or-1*10-6 eV bar-1 and +6+or-1*10-6 eV bar -1 respectively. The levels are interpreted as being possibly associated with the higher lying conduction band states. The use of the mobility variations with pressure is shown to be a powerful method of determining the dominant scattering mechanisms at different carrier concentrations.