[Defect analysis in mercury cadmium telluride by Raman scattering]

Telluride precipitates in HgCdTe(MCT) and Raman scattering peaks of Hg vacancies are reported. We also analyze the relationship between the crystal surface perfection of MCT and its second-order scattering peaks. Intense bands at 125 and 145 cm-1 confirm them to be precipitates, and there is 2 cm-1 shift to high frequency in comparison with intense bands of normal trigonal Te. This shows the compressive stress exists around Te precipitates. The weak Raman peak at 108 cm-1 arise from Hg vacancies. This peak is only found in p-type MCT and MCT including p-n junction, and is not found in n-type MCT. The intensity of the second-order scattering peaks in MCT is very sensitive to its crystal surface perfect. To good surface perfect, these peaks are very distinct, and to poor surface perfect, they are not distinct. The intensity measurement of 2LO(T) mode in the second-order scattering peaks can provide useful information for surface analysis in crystal preparation process.