Self-assembled one-dimensional hierarchical SiC nanostructures: Microstructure, growth mechanism, and optical properties

Self-assembled one-dimensional (1-D) hierarchical SiC nanostructures were synthesized by heating a milled Si and SiO2 powder mixture in the presence of ZnS. Structure and morphology characterizations revealed that the 1-D hierarchical SiC nanostructures are single crystalline and consisted of consecutive truncated cones along its length. A vapor-solid (VS) self-assembly mechanism is proposed for the formation of the hierarchical SiC nanostructures. ZnS is recognized to act as a SiC nucleation initiator and to regulate the formation of the consecutive truncated cones. The as-synthesized I-D hierarchical SiC nanostructures exhibit a strong sharp blue emission at 445.2 nm, as well as a broad weak cyan emission ranging from 475 to 500nm. The study may be helpful to understand the formation of complex nanostructures and may find potential applications in nanodevices. (C) 2008 Elsevier B.V. All rights reserved.