US nanobelts as photoconductors

Mass production of sing le-crystalline CdS nanobelts is achieved by thermal evaporation of CdS powders with the presence of Au catalyst. The as-synthesized CdS nanobelts are usually hundreds of nanometers to tens of micrometers in width, tens of nanometers in thickness, and several hundreds of micrometers in length. CdS nanobelts have a pronounced increase in conductance of up to four orders of magnitude upon exposure to white light, and also very fast response time about 1-3 s. The photoconductivity mechanism of CdS nanobelts is discussed. The results demonstrate the potential of fabricating nanosized photoconductors and optical switches using the integrity of a single CdS nanobelt. (c) 2005 American Institute of Physics.