Carrier recombination dynamics through defect states of ZnO nanocrystals: From nanoparticles to nanorods

► Size-selected ZnO nanoparticles and nanorods synthesized and characterized. ► Radiative recombination rate slows down with increasing particle size up to ∼5 nm. ► Recombination dynamics becomes faster on transition from nanoparticles to nanorods. ► Contributions to lifetimes rather than the time-constants result in observed trends. ► New topological surface states in anisotropic shape responsible for this change.