Optical bandgap tailoring through compositional tuning in thermally evaporated antimony sulphoselenide solid solution thin films

Antimony chalcogenides solid solution (Sb _2 (S _1− _x Se _x ) _3 ) exhibit tunable optoelectronic properties suitable in various optoelectronic devices. Solid solution thin films were grown using thermal evaporation, followed by post-sulfurization/selenization at temperatures ranging from 250 °C–325 °C to modulate optoelectronic properties through compositional tuning. X-ray diffraction and Raman spectroscopy studies confirmed the phase formation. Scanning electron microscopy and energy-dispersive x-ray analysis revealed uniform surface morphology and composition as expected for the solid solution. Tailorable bandgap values from 1.72 eV to 1.30 eV were achieved for the compositional values varied between Sb _2 S _3 –Sb _2 Se _3 , in solid solution films grown at 100 °C and post processed at 300 °C.