Interface confinement on the exciton recombination in thin CdS/ZnO shell/core nanowires

The modulation of exciton recombination is one of the core issues for the electronic/optoelectronic devices. Here, we investigate the exciton recombination and surface depletion of ZnO nanowires under various interface conditions in terms of continuum medium mechanics and bond relaxation method. We find that the enhancement of donor concentration, nanowire dimension and external temperature can modify the carrier recombination, surface barrier height and surface depletion depth. Moreover, coated a thin epitaxial layer on the nanowires is of great benefit to reduce the surface state for suppression of recombination rate. The related mechanism on the interface confinement has also been clarified. Our predictions agree well with the experimental measurements, which provide an effective guidance for the organization of electronic device design.