SEM images of samples after the metal catalytic etching. (a) SEM image of SiNW arrays after 5-min solution etching. (b) Gauss fit of the dimension of the spheres, holes, and top and bottom of nanowires. (c), (d) SEM images of samples using 200-nm PS sphere template; the samples have been etched by solution for 2 and 5 min, respectively.
Su et al. Nanoscale Research Letters 2013 8:405 doi:10.1186/1556-276X-8-405