Preparation, characterization and ab-initio study of CdSnTe2 thin films by closed space sublimation technique

The cadmium tin telluride (CdSnTe) alloy was prepared by direct reaction of high purity elemental constituents using rotating furnace. Thin films of CdSnTe different thickness were prepared on glass substrates by vacuum closed space sublimation method. The films were subjected to XRD, SEM, EDAX and UV-vis-NIR studies. The crystalline structure of CdSnTe alloy was found to be face-centered cubic with lattice parameter 6.30 Å. EDAX studies confirmed the composition of the alloy as CdSnTe2 compound. The UV-vis-NIR optical transmission spectra of thin films of different substrate temperatures were obtained. The energy band gap found to be in the order of 1.5 eV. The band gap is suitable for LEDs, optoelectronics and photovoltaic applications. First principle density functional theory calculations of CdSnTe2 structure were performed by using Vienna ab-initio simulation package software. The results of theoretical calculations are in good agreement with experimental data.