Study of the optical properties of Sb2(Se1-xSx)3 (x=0-1) solid solutions

This study presents a detailed analysis of the optical properties of the Sb-2(Se1-xSx)(3) (x = 0-1) polycrystals. Four antimony selenosulfide solid solutions Sb-2(Se1-xSx)(3) together with Sb2Se3 and Sb2S3 were synthesized from elemental precursors at the same synthesis conditions, only varying the x = S/(Se + S) value with a step of delta x = 0.2. Successful formation of the Sb-2(Se1-xSx)(3) solid solutions was determined by Raman spectroscopy and X-ray diffraction. As expected for the same type of crystal structure of Sb2Se3 and Sb2S3, the bimodal behavior of Ag Raman mode in Sb-2(Se1-xSx)(3) was detected. Temperature and excitation power dependent photoluminescence (PL) analysis of Sb-2(Se1-xSx)(3) was performed in order to look into the electronic and defect structure of these promising semiconductor materials for optoelectronic applications. The shift of the near band edge PL emission in Sb-2(Se1-xSx)(3) towards higher energies from 1.309 eV to 1.728 eV with increasing sulfur content was detected at T = 3 K. A change in the radiative recombination mechanism was detected being of excitonic origin in samples with x <= 0.2 and resulting from deep donor-deep acceptor pair recombination in samples with x > 0.2.