InAs nanowires and whiskers grown by reaction of indium with GaAs

Free-standing InAs nanowires and whiskers were grown employing reaction of indium (In) liquid and vapor with GaAs substrate. The arsenic (As) atoms resulting from this reaction were transported by a flow of N-2 or NH3 to the growth location where they reacted with In to produce InAs nanowires and whiskers. Scanning electron microscopy, energy dispersive x-ray spectroscopy, and transmission electron microscopy of the products indicate that the diameter of the nanowires and whiskers ranges from 15 nm to 2 mum depending on the growth temperature, the composition is InAs, and the structure is zinc-blende crystal with [110] or [100] growth direction. The As source and growth mechanism were discussed. The method for synthesis involved no any template, catalyst, toxic As source, nor even lattice matched substrate. (C) 2003 American Institute of Physics.