Synthesis of self-assembled silicon nanowires with uniform small diameter

Self-assembled silicon nanowires were synthesized with silicon monoxide as starting materials and argon as protection gas. The growth temperature was controlled at 480degC with the pressure at 2.8 MPa. Transmission electron microscopy (TEM) showed that the diameter of the silicon nanowires distributed form 5 run to 7 nm. In the high-resolution TEM image, the crystalline silicon core with diameter about 3~5 nm was clearly revealed. When the growth time was prolonged, the lengths of the nanowires increased, but their diameters were still less than 7 run. Influenced by the quantum effect, Raman spectrum of the silicon nanowires was found to be blue shifted. Considering thermodynamics of nucleation, we presumed that the ambiance pressure was the decisive factor for the small size nanowires growth.