Catalyst-Assisted Vapor−Liquid−Solid Growth of Single-Crystal CdS Nanobelts and Their Luminescence Properties

Abstract

Mass production of CdS nanobelts is successfully achieved by a simple thermal evaporation of CdS powders under controlled conditions in the presence of Au catalysts. The as-synthesized CdS nanobelts are single-crystalline with wurtzite structure, usually several hundred nanometers in width, tens of micrometers in length, and tens of nanometers in thickness. The room-temperature photoluminescence spectrum of CdS nanobelts features three luminescence peaks around 504, 513, and 770 nm, which are attributed to the band-edge, band-to-band and surface state emissions, respectively. The growth of CdS nanobelts is initiated by Au catalyst nanoparticles via a catalyst-assisted vapor−liquid−solid process, and a side growth along the belt width direction via a vapor−solid process is also suggested. This synthetic method offers the possibility for the control of CdS nanobelts on a special substrate, which would be of particular interest for their applications in optoelectronic devices.