TEM images of the GaAs nanowires catalyzed by Au thin films of different thicknesses. The thicknesses of the Au thin films are (a) 0.5, (b) 1, (c) 2, (d) 3, and (e) 5nm. The two insets in (a), (b), and (c) are the enlarged views of the region containing the catalyst and the nanowire, and the region containing only the nanowire. The insets in (d) and (e) are the enlarged views of the regions that contain both the catalyst and the nanowire.
Xu et al. Nanoscale Research Letters 2012 7:589 doi:10.1186/1556-276X-7-589