Size, shape-dependent growth of semiconductor heterostructures mediated by Ag2Se nanocrystals as seeds

Size- and shape-controllable Ag2Se-ZnS nanorods (NRs) and nanowires (NWs) have been synthesized successfully by the solution-liquid-solid (SLS) method. By using Ag2Se nanocrystals (NCs) as seeds and catalyst, colloidal Ag2Se-ZnS NRs and NWs with controllable diameters and lengths in ranges of 5-12 nm and 15-600 nm were successfully synthesized by altering the experimental variables, such as diameter of Ag2Se NCs, amount of precursor, reaction time, and reaction temperature. The Ag2Se NCs not only played a key role in the control of the shape of ZnS NCs but also influenced the crystal structure of ZnS NCs. The related surface photovoltage of heterostructured Ag2Se-ZnS NWs have also been studied and the formation of Ag2Se-ZnS heterostructure was confirmed. Moreover, this SLS method was successfully exploited to synthesize Ag2S-ZnS heterostructures.