A New Route to Large-Scale Synthesis of Silicon Nanowires in Ultrahigh Vacuum


  • We thank Prof. L. L. Cao and Prof. Z. W. Yu for their valuable advice. Financial support of this work by the Ministry of Science and Technology of China (2001CB6105) and the National Natural Science Foundation of China (NSFC 599101611982, 29973001) is acknowledged.


An approach for the large-scale synthesis of high-purity silicon nanowires (SiNWs) in ultrahigh vacuum is presented. A mixture of Si and SiO2 is evaporated by an electron beam, and the growth temperature is 700 °C, which is much lower than those used for other oxide-assisted growths. A new type of single-crystal SiNWs, with [221] orientation, is thus synthesized. Moreover, it is experimentally demonstrated that SiO intermediates are formed in the process, and the nanowires are obtained via a disproportionation reaction of 2SiO → Si + SiO2. A growth mechanism is proposed and the critical factors for the formation of 1D nanowires are also determined. The approach is particularly compatible with the mature Si-based technology, and is favorable for device integration and practical applications.