Effects of size restriction on donor-acceptor recombination in AgBr

Abstract
The behavior of donor-acceptor (DA) recombination luminescence in quantum confined AgBr has been investigated. The DA luminescence decay, after pulsed excitation, became longer lived as the nanocluster size decreased. This result differs from theoretical expectations and from observations with AgI nanoclusters. The DA lifetime increase with decreasing size is due to an increase in yield and lifetime of “free” excitons that slowly dissociate into “close” donor-acceptor pairs, giving rise to an “exciton dribbling” effect.