Enhanced Nickel-Seeded Synthesis of Germanium Nanowires

Germanium (Ge) nanowires can be grown using either gold (Au) or nickel (Ni) seeds in a supercritical solvent; however, the quality and yield of the nanowires is much higher using Au seeds and diphenyl germane (DPG) as a reactant under typical reaction conditions. We find that the addition of monophenylsilane (MPS) dramatically improves the yield and quality of Ni-seeded Ge nanowires, producing straight nanowires with relatively uniform diameter and nearly 100% conversion of DPG to Ge. MPS participates in the phenyl redistribution reaction of DPG and serves as a phenyl sink that speeds DPG decomposition and increases the conversion to Ge to nearly 100%. MPS addition to Au-seeded nanowire reactions also increases the DPG conversion to Ge to nearly 100% and improves the nanowire quality at higher growth temperature.