Study on crystal orientation-dependent effective mass in III?V semiconductors

A numerical approach is presented to calculate crystal orientation-dependent effective mass of heavy hole, light hole and spin-orbit split-off hole of III-V semiconductors (GaAs, InAs, InP, GaSb, and InSb etc.) at Gamma-point by envelope approximation using k.p method. Unitary transformation is used to modify the wave vector and eight-band k.p Hamiltonian is applied in conventional (100) crystal orientation. The simulation is carried out for conventional crystal orientations (100), (110) and (111) as well as non-conventional orientations (113), (131) and (201). It is found that there is a substantial correlation between the effective mass and the crystal orientation. The results obtained from conventional crystal orientations are compared with that of estimated by well-established PBE, HSE and MBJLDA methods and found to have within good agreement. This indicates that the proposed technique can be applied to evaluate effective mass in arbitrary orientation of III-V semiconductors. It is also found that (113) orientation possesses lowest effective mass than other orientations. The outcome of this paper would be a boost to design high-speed optoelectronic devices with improved performance by introducing non-100 oriented epitaxial layers.