Articles including an array of one-dimensional or three-dimensional nanopillar arrays disposed on a substrate and methods for the formation thereof. The methods can include filling a plurality of hollow nanopillars, which are supported on a substrate, with a first conductive material and removing the plurality of hollow nanopillars to leave a plurality of vertically-aligned, epitaxial nanopillars, comprising the first conductive material, on the substrate.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 The United States Government has rights in this invention pursuant to contract no. DE-AC05-00OR22725 between the United States Department of Energy and UT-Battelle, LLC.