Temperature dependence of morphology and diameter of silicon nanowires synthesized by laser ablation

The silicon nanowires (SiNWs) with different diameters and morphologies were synthesized by laser ablation of a target containing metals over a temperature range 910-1120 degreesC. The octopus-shaped wires of larger diameters were formed in lower temperature zone (910-960 degreesC), while SiNWs and silicon nanoparticle chains of smaller diameters in higher temperature zone (960-1120 degreesC). The distribution of the morphology and diameter of SiNWs as a function of growth temperature differs from that reported by thermal evaporation of SiO powders. The study shows that the morphology and diameter of SiNWs synthesized by laser ablation not only correlate closely with the growth temperature of SiNWs, but also with the nature of a catalyst. By change of nucleation temperature and critical nucleus size of nucleus droplets in vapor-liquid-solid (VLS) growth process, a catalyst can change relationships between the morphology. diameter, and growth temperature of SiNWs. (C) 2002 Elsevier Science B.V. All rights reserved.