Novel route to scalable synthesis of II–VI semiconductor nanowires: Catalyst-assisted vacuum thermal evaporation

Vacuum thermal evaporation, a conventional film fabricating technique, has been explored to synthesize II–VI semiconductor nanowires based on a catalyst-assisted vapor–liquid–solid (VLS) process. Low melting-point metals, such as bismuth and tin, can be used as catalysts by co-evaporating with desired semiconductor materials. As proof of the concept, CdTe, CdS, ZnSe and ZnS single crystalline nanowires have been successfully synthesized on a large scale by this method. The growth mechanism involved in the method has been discussed. Morphological, structural and optical properties of as-synthesized nanowires were characterized, revealing the high quality of the nanowires. The results indicate that the method presented here is a novel and general route to mass production of II–VI semiconductor nanowires, which can be possibly scaled up for industrial application at low cost, and extended to other material systems.