Low-temperature synthesis of ZnSe nanowires and nanosaws by catalyst-assisted molecular-beam epitaxy

Abstract

Single-crystal ZnSe nanowires are grown on a prepatterned gold catalyst by molecular-beam epitaxy. Optimum selectivity and maximum nanowire densities are obtained for growth temperatures in the range $400–450°\mathrm{C}$ , but gold-assisted growth is demonstrated for temperatures as low as $300°\mathrm{C}$ . This suggests a diffusion process on/through the catalyst particle in the solid state, in contrast to the commonly assumed liquid phase growth models. Straight wires, as thin as $10\mathrm{nm}$ , nucleate together with thicker and saw-like structures. A gold particle is always found at the tip in both cases.