Surface sulfurization of ZnO/ZnS core shell nanowires and shell layers dependent optical properties

With the unique properties and superior performance, ZnO/ZnS core shell nanostructures have been applied in many photoelectric devices. Varied growth methods can synthesize ZnO/ZnS core shell samples, which exhibit different crystal and optical properties, and have the positive or negative effect on performance of related devices. To investigate the growth and properties, ZnO/ZnS core shell nanowires were grown through surface sulfurization. X-ray diffraction and scanning electron microscopy measurements indicated surface sulfurization degree can affect crystal quality. In addition, photoluminescence results exhibited that ZnO/ZnS heterojunction emission properties were dependent on shell layers quality. By increasing the amount of surface powder, it would improve shell layers' crystal quality. And with optimal surface sulfurization degree, the vacancies and interstitial atoms defects can be restrained, which may improve photo-generated carriers separation efficiency.