INTER-VALENCE-BAND TRANSITIONS IN UNIAXIALLY STRESSED GE AND GAAS

The spectra of direct transitions between the heavy-hole band and the spin-orbit-split band in strained Ge and GaAs have been studied. The interpretation involves an approximate k•p treatment in which the strong interaction between the conduction band, the light-hole band, and the spin-orbit-split band was taken into account. There is satisfactory agreement between our experiments on p-type Ge and cyclotron-resonance data. Our studies of p-type GaAs provide information on the warping of the hole surfaces and the ratio of light-hole to heavy-hole masses. The results were BA=0.69±0.015 and N3A=0.86±0.01 for GaAs at room temperature. In both materials there was evidence of considerable freeze-out of holes at temperatures less than 100°K. Our results for the valence-band deformation potentials agree with previous piezo-optical experiments. © 1969 The American Physical Society.