Time-Resolved Photoluminescence Spectroscopy in AmorphousAs2S3

Abstract

Measurements of time-resolved photoluminescence spectra at 2 K from amorphous ${\mathrm{As}}_2$ ${\mathrm{S}}_3$ on a 10-nsec time scale demonstrate that two independent luminescence processes exist simultaneously. The higher-energy luminescence process at 1.75 eV has a very short lifetime and is rapidly quenched at higher temperatures. The other process appears at lower energy (1.45 eV) and shifts to considerably lower energy with increasing time delay. A model to explain this result is proposed.