Seeded germanium nanowire synthesis in solution

Abstract

Germanium nanowires were synthesized by the thermal decomposition of diphenylgermane (DPG) in the presence of gold nanocrystals in various high boiling solvents, including squalane, squalene, octacosane, dotriacontane, and trioctylamine (TOA). The DPG decomposition chemistry was studied in these solvents. In all of the solvents except dotriacontane, DPG decomposition leads to only amorphous Ge particles unless Au nanocrystals are added to induce solution-liquid-solid (SLS) nanowire growth. In dotriacontane, crystalline nanowires were observed to form spontaneously without the addition of Au. DPG decomposes to Ge by disproportionation and in squalane and squalene the Au nanocrystals significantly increase the DPG decomposition rate. In dotriacontane, DPG decomposition was relatively fast in the absence of Au nanocrystals with the formation of crystalline nanowires, but chemical analysis of the solvent and the tips of the nanowires revealed the presence of copper and alkali and alkaline impurities that are responsible for the apparently unseeded nanowire growth.