Interband transitions of InAs_xSb_(1-x) alloy films

摘要

We report pseudodielectric-function spectra from 1.5 to 6.0 eV of InAs_xSb_(1-x) ternary alloys obtained by spectroscopic ellipsometry. Energies of the E_1, E_1 + △_1, E_0', E_0'+△_0', E_2, E_2+△_2, E_2', E_2' + △_2', and E_1' critical points (CPs) were obtained from numerically calculated second derivatives, and identifications established by band-structure calculations using the linear augmented Slater-type orbital method. The E_2, E_2 + △_2, E_2', and E_2' + △_2' CP structures cross with increasing As-composition. Two saddle-point transitions, △_5~(cu)-△_5~(vu) and △_5~(cl)-△_5~(vu), are found for InSb.