Influence of halogen precursors on the growth of InSb nanostructures

The present work highlights the role of halogen compounds in modifying the shape of the InSb nanostructures, while maintaining a high crystalline quality of the nanostructures. One-dimensional (1D) nanowires (NWs) and two-dimensional (2D) nanoplatelets (NPLs) were synthesized by ambient pressure chemical vapor deposition. Our experimental results suggest that at a critical growth temperature of 512 ^∘C, InSb NWs grow by the traditional vapor-liquid-solid growth mechanism when gold (Au) nanoparticles are used to initiate growth on an InSb film. The resulting NWs were found to have a cylindrical or tapered shape, were of high crystalline quality, and had stoichiometric composition. In the presence of halogen precursors, a change in morphology was observed and the resulting nanostructures were 2D NPLs and faceted NWs. Using existing models of crystal growth and concepts of volume, surface and edge energies, the experimental results are explained on the basis of chlorine atoms adsorbed on the wide or narrow facets of a nanocrystal, initiating nucleation and facilitating NPL or faceted NW formation. The incorporation of the chlorine atoms add a new degree of freedom to CVD synthesis of nanostructures and the results are promising for the controlled growth of novel 1D and 2D nanostructures for nano-electronic devices.