On demand-direct synthesis of Si and Ge nanowires on a single platform by focused laser illumination

Laser irradiation can incur spatially confined and rapid heating that enables precisely controlled nucleation and subsequent growth of nanomaterials. This localization of the laser-driven growth can realize on-demand, direct synthesis of nanowires composed of multiple elements on a single platform. In this study, silicon and germanium nanowires are grown by laser-induced vapor-liquid-solid mechanism in a hetero-array configuration by simply switching the reactant gas precursors as the growth of nanowires is limited within the heat-affected zone induced by the laser. Energy dispersive x-ray and Raman spectroscopies were performed to observe the elemental composition and crystallinity of as-grown nanowires, respectively.