SEM images of GaAs NWs. These NWs were grown for 5 s (samples A1 and a2), 60 s (sample B1), and 1,800 s (sample C1). During the initial stage of growth, GaAs traces are formed (sample a2), as seen in the inset (A1), evolving into island type structures and finally nanowires. Images of samples A1 and B1 represent top views, whereas the sample C1 image is shown in cross-sectional view in order to visualize the vertical nanowires.
Davydok et al. Nanoscale Research Letters 2012 7:109 doi:10.1186/1556-276X-7-109