Figure 2
From: Ordered arrays of nanoporous silicon nanopillars and silicon nanopillars with nanoporous shells
SEM images of nanopillars formed from the highly doped Si in λ 3 solution. After etching for 3 min (a, b), 6 min (c, d), and 10 min (e, f), respectively. Panels b, d, and f show the cracked nanopillars. These cracks were formed during breaking of the samples for the SEM investigation. The distance mark in (a) indicates the range of the nanoporous base layer underneath the Au film and the nanopillars.