This is an Open Access article distributed under the terms of the Creative Commons Attribution License (
http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The XRD spectra and ZNO peak ratios. (a) XRD spectra of NWs grown on pre-coated substrates with different thickness (from top to bottom, 2, 4, 6, 8, 10, 20, and 50nm). (b) ZnO peak ratios for (1 0 1) to (0 0 2) as a function of substrate thickness.