Electronic structure of GaAs under strain.

Christensen N.E.

Results of self-consistent relativistic band calculations for GaAs under hydrostatic as well as uniaxial strain are presented. Deformation potentials related to the splitting of the valence-band edge ( Gamma 15nu ) are calculated with and without inclusion of spin-orbit coupling. The trigonal-shear deformation potentials that agree with experiments correspond to an internal-strain parameter zeta =0.6+or-0.1. The calculated values, 16-19 eV, of the optical deformation potential d0 are substantially smaller than the published experimental results ( approximately=41 eV). The E0 gap obtained in the local-density approximation is 0.25 eV. A method of correcting for this error and for calculating, self-consistently, the lowest s-like conduction band is described, and used to derive pressure dependences of the gaps and conduction-band masses. The parameters for this adjustment of the conduction band are determined for zero pressure, and can be kept pressure independent. The author finds (1/mc*)dmc*/dP=0.68*10-2 kbar-1. The pressure at which conduction-band inversion occurs is 30.5 kbar. The value calculated for shear deformation potential E2L is 19 eV for zeta =0.6. The spin-orbit-induced splitting of the lowest conduction band for k mod mod (110) and the additional strain-induced splitting are calculated and related to experimental results for spin relaxation of photoexcited electrons.

Physical Review B, 30 5753-65, 1984.

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