Germanium Nanowire Synthesis: An Example of Solid-Phase Seeded Growth with Nickel Nanocrystals

Germanium nanowires were synthesized by thermal decomposition of diphenyl germane in the presence of nickel (Ni) nanocrystals in supercritical toluene at 27.8 MPa and temperatures ranging from 410 to 460 °C. The growth temperature is well below the lowest Ni−Ge eutectic temperature (762 °C), and nanowire crystallization appears to occur by solid-phase alloying of the seed particle. We call this nanowire growth mechanism supercritical fluid−solid−solid (SFSS) synthesis.