Raman scattering and band gap modification in Fe doped CdTe by Sb substitution

CdTe is compound of II-VI group semiconducting material that is used for photovoltaic energy conversion because of its direct energy band gap, ease of fabrication, stable nature in air, and excellent absorption efficiency. It is possible to expand its application to other areas through an improvement brought about by doping. In this regard, the vacuum sealing approach is utilized for the making of Fe_0.05(CdTe)_1−xSb_x samples for x = 0, 0.03, 0.05, and 0.10 bulk alloys. Different analyses performed include the study of the structural characteristics, bandgap variations, and vibrational characteristics of the bulk alloys. From the X-ray diffraction pattern, the cubic structure of the single-phase CdTe structure is confirmed. The band gap values of the samples decrease from 1.35 eV to 1.27 eV, resulting from the inclusion of Sb in Fe-doped CdTe. The transverse-optical (TO) phonon mode present in pure CdTe splits as a result of the addition of Sb, as observed in the Raman spectra at room temperature.