Multi-peak photoluminescence in ZnO nanocrystals studied by time-resolved and spatially-resolved photoluminescence spectroscopies

Photoluminescence (PL) properties of ZnO nanocrystals were studied by using time-resolved and spatially-resolved PL spectroscopies. Three PL peaks (α,β, and γ lines) were observed at 20 K and only the α line was observed in diluted ZnO nanocrystal dispersed glass films. The time-resolved PL measurements revealed that the α line decayed single exponentially, while the β line decayed non-exponentially. From these experimental results the origins of the observed PL peaks were discussed.