Diameter-dependent composition of vapor-liquid-solid grown Si(1-x)Ge(x) nanowires.

Research paper by Xi X Zhang, Kok-Keong KK Lew, Pramod P Nimmatoori, Joan M JM Redwing, Elizabeth C EC Dickey

Indexed on: 27 Sep '07Published on: 27 Sep '07Published in: Nano Letters


Diameter-dependent compositions of Si(1-x)Ge(x) nanowires grown by a vapor-liquid-solid mechanism using SiH(4) and GeH(4) precursors are studied by transmission electron microscopy and X-ray energy dispersive spectroscopy. For the growth conditions studied, the Ge concentration in Si(1-x)Ge(x) nanowires shows a strong dependence on nanowire diameter, with the Ge concentration decreasing with decreasing nanowire diameter below approximately 50 nm. The size-dependent nature of Ge concentration in Si(1-x)Ge(x) NWs is strongly suggestive of Gibbs-Thomson effects and highlights another important phenomenon in nanowire growth.