Optical constants of Hg/sub x/Cd/sub 1-x/Te alloys

Abstract

Optical constants of Hg/sub x/Cd/sub 1-x/Te alloys are modeled for the first time over the spectral range from 1.5 eV to 6.0 eV for all compositions 0/spl les/x/spl les/1. The employed model is the modified Adachi's model, which utilizes variable line broadening instead of the conventional Lorentzian one. The model takes into account transitions at critical points E/sub 0/, E/sub 0/+/spl Delta//sub 0/, E/sub 1/, E/sub 1/+/spl Delta//sub 1/, E/sub 0/', E/sub 2/(X), and E/sub 2/(/spl Sigma/), as well as excitonic effects at the lowest four critical points. Model parameters are determined using a global optimization routine, namely an acceptance-probability-controlled simulated annealing algorithm. Excellent agreement with the experimental data is obtained in the entire investigated energy and composition ranges.