ZnSe–Si Bi-coaxial Nanowire Heterostructures


  • This work was supported by The National Natural Science Foundation of China and Anhui Education Department, P.R. China (No. 2005KJ035ZD). We also acknowledge the KOSEF for partial financial support. G.-C. Yi was supported by the National Creative Research Initiative Project of the Ministry of Science and Technology, Korea.


We report on the fabrication, structural characterization, and luminescence properties of ZnSe/Si bi-coaxial nanowire heterostructures. Uniform ZnSe/Si bi-coaxial nanowire heterostructures are grown on silicon substrates by the simple one-step thermal evaporation of ZnSe powder in the presence of hydrogen. Both ZnSe and silicon are single-crystalline in the bi-coaxial nanowire heterostructures, and there is a sharp interface along the nanowire axial direction. Furthermore, secondary nanostructures of either ZnSe nanobrushes or a SiOx sheath are also grown on the primary bi-coaxial nanowires, depending on the ratio of the source materials. The experimental evidence strongly suggests that bi-coaxial nanowires are formed via a co-growth mechanism, that is, ZnSe terminates specific surfaces of silicon and leads to anisotropic, one-dimensional silicon growth, which simultaneously serves as preferential nucleation sites for ZnSe, resulting in the bi-coaxial nanowire heterostructures. In addition, the optical properties of ZnSe/Si nanowires are investigated using low-temperature photoluminescence spectroscopy.