Exciton and Pair Recombination at Intimate Valence-Alternation Pairs in a-As2S3

Abstract

Optically detected magnetic resonance in $a$-${\mathrm{As}}_2$ ${\mathrm{S}}_3$ has shown that the emission consists of a high-energy triplet exciton recombination overlapping a low-energy pair process. The results are consistent with recombination at axial defects such as ($D^{+}, D^{-}$) intimate valence-alternation pairs.