Optical properties of InxAl1-xAs alloy films

Abstract

Pseudodielectric functions <epsilon > of InxAl1-xAs ternary alloy films were determined from 1.5 to 6.0 eV by spectroscopic ellipsometry. We minimized overlayer effects by performing wet-chemical etching to more accurately determine intrinsic bulk dielectric responses. Energies of the E-1, E-1+Delta(1), E-0&apos;, E-2, E-2+Delta(2) and E-2&apos; critical points (CPs) were identified by band structure calculations of the linear augmented Slater-type orbital method. These calculations also showed a crossing of the E-0&apos; and E-2 CP structures with increasing In composition and a new saddle point in the AlAs band structure. (C) 2008 American Institute of Physics.