Oxygen in antimony triselenide: An IR absorption study

Abstract

Oxygen in single crystalline antimony triselenide (Sb2Se3) is addressed by infrared (IR) absorption spectroscopy. Measurements conducted on Sb2Se3 samples doped—during growth, post-growth annealing in the O2 ambient, or by O ion implantation—with 16O reveal an IR absorption line at 527 cm−1 (10 K). Substitution of 16O by 18O “red”-shifts the signal down to 500 cm−1 based on which the line is assigned to a local vibrational mode of an isolated oxygen defect. Annealing of O-enriched samples in hydrogen atmosphere at temperatures above 380 °C results in the suppression of the 527-cm−1 line and concurrent appearance of the signals due to hydroxyl groups, suggesting formation of oxygen-hydrogen complexes. The configuration of the 527-cm−1 oxygen center is discussed.