Visible and ultraviolet reflectivity of Hg1−xCdxTe

The reflectivity and wavelength-modulated reflectivity of Hg1−xCdxTe samples were measured in the 2.0–8.8 eV energy range to determine the dependence of the spectral features E1, E1+Δ1,A, and B on composition and on temperature. Spectral features of mechanically polished surfaces and sputter-etched surfaces were broadened, decreased in magnitude, and shifted to lower energies than those features of Br2-etched surfaces. At low temperatures, the spectral features of chemically etched surfaces narrow appreciably more than polished or sputter-etched surfaces, indicating that at room temperature there is a large thermal contribution to the width of the spectral features of chemically etched surfaces.