Structure control of CdS nanobelts and their luminescence properties

摘要

Single crystalline CdS (hexagonal) nanobelts have been synthesized using thermal evaporation at temperatures ranging from 1000 to 1200℃. These nanobelts universally grow along the [120] crystalline direction. The nanobelts fabricated at 1000℃ appear to be much more uniform than those at 1200℃. Moreover, the surface of the nanobelts grown at 1200℃ is rough compared to that of the former, which is due to the secondary growth of CdS crystallites on the nanobelts' surfaces at higher temperatures, as induced by the surface polarity. Cathodoluminescence and photoluminescence studies disclose the different electronic structure qualities of the two samples. The growth mechanisms of the nanobelts and the luminescence differences of the two samples are discussed.