Date of download: 10/10/2017 Copyright © ASME. All rights reserved. From: Single-Crystalline, Nanoporous Gallium Nitride Films With Fine Tuning of Pore Size for Stem Cell Engineering J. Nanotechnol. Eng. Med. 2014;5(4):040903-040903-9. doi:10.1115/1.4030615 Figure Legend: TEM analysis of nanoporous GaN films. (a) The nanopores uniformly cover the surface of GaN film. (b) Higher magnification image shows the pore size is ∼20 nm (doping concentration = 5 × 1018 cm−3 and etching voltage = 10 V). (c) Selected-area electron diffraction pattern (SAD) of the nanoporous GaN membrane shows the sixfold symmetry along the [0001] axis. The scale bar in (a) is 200 nm and (b) is 20 nm.