Temperature and Alloy Compositional Dependences of the Energy Gap of Hg1−xCdxTe

The temperature and compositional dependences of the energy gap are determined for the alloy semiconductor mercury‐cadmium telluride (Hg_1−xCd_xTe). The cutoff wavelength was measured on photoconductive and photovoltaic infrared detectors where 0.17<x<0.60 over a temperature range 20<T< 300°K. Spectral response curves are shown to indicate the precision of the method. The temperature and compositional dependences of the energy gap are shown and the empirical expression $$E_g(\mathrm{eV}{\text{)\hspace{0.17em}=1.59x−0.25+5.233(10}}^{\text{−4}}{\text{)T(1−2.08x)+0.327x}}^3$$ is deduced.