Colloidal Synthesis of Germanium Nanorods

A colloidal synthesis of crystalline germanium (Ge) nanorods is reported. Diphenylgermane (DPG) is decomposed in a high boiling solvent in the presence of bismuth (Bi) nanocrystals and trioctylphosphine oxide (TOPO). The Bi nanocrystals induce solution−liquid−solid (SLS) growth of the Ge nanorods, and TOPO serves as a capping ligand to prevent aggregation. The resulting nanorods are crystalline, predominantly growing in the ⟨111⟩ crystallographic direction, with an average diameter of 10 nm. The average length could be varied from 60 to 170 nm by decreasing the ratio of Bi to Ge in the reaction. The addition of poly(vinylpyrrolidinone) /hexadecene (PVP/HDE) copolymer led to branched nanorods.