Mechanism of oxide-assisted nucleation and growth of silicon nanostructures

Based on a systematic study of gas-phase silicon oxide clusters and the sub sequent interesting findings such as the gas-phase favorable composition an d distinctive features in reactivity of the different silicon oxide cluster s, we have elucidated the mechanism of oxide-assisted nucleation of silicon nanostructures. In the mechanism, a part of the highly reactive Si atoms i n the silicon suboxide clusters deposited on the substrate would form bonds with the substrate atoms, anchoring the cluster to the substrate. The rema ining reactive Si atoms facing outwards from the substrate are exposed to t he vapor, favoring further stacking of silicon oxide clusters. They act as the nuclei to absorb reactive silicon oxide clusters and facilitate the for mation of the Si nanowires with a certain crystalline orientation. We expec t that the present oxide-assisted formation mechanism of nanostructures may be applicable to a wide range of materials synthesis or design. (C) 2001 E lsevier Science B.V. All rights reserved.