The configurational behavior of sulfur in antimony triselenide (Sb2Se3) is investigated by combining infrared absorption spectroscopy with density functional theory. Four sulfur-related local vibrational modes are identified at 249, 273, 283, and 312~cm−1 in melt-grown single crystals prepared from Sb2Se3 granulate. Their assignment to sulfur is confirmed through controlled indiffusion experiments using Sb2S3 and elemental sulfur, as well as isotope-substitution studies with 34S, which produce the expected frequency shifts. Polarization-resolved measurements, together with theoretical calculations of local vibrational modes, demonstrate that the observed spectral features are fully consistent with substitutional sulfur on the three inequivalent selenium sites of Sb2Se3.
@article{arxiv.2510.14590,
title = {Substitutional sulfur and its vibrational fingerprints in Sb$_2$Se$_3$},
author = {F. Herklotz and E. V. Lavrov and A. Herklotz and V. V. Melnikov and T. P. Shalvey and J. D. Major and and K. Durose},
journal= {arXiv preprint arXiv:2510.14590},
year = {2025}
}