Core-shell nanowire arrays of metal oxides fabricated by atomic layer deposition

Atomic layer deposition (ALD) has proven to be an excellent candidate for the deposition of thin layers onto various nanostructures to create core-shell structures with new functionalities and improved device application potential. The authors have used ALD to fabricate metal oxide core-shell nanowires based on electrodeposited ZnO nanowire arrays and Al(2)O(3), ZnO, and TiO(2) shells. The authors observe distinctive features of the core-shell nanowires induced by the shell coatings. Most notably, the photoluminescence of the nanowire cores can be enhanced or depleted by the shell, depending on the choice of shell material. Specifically, ZnO-Al(2)O(3) core-shell nanowires display improved optical characteristics over their bare ZnO nanowire core equivalents. These results have important implications for related optoelectronics based on ZnO nanowires or their core-shell nanostructures. (C) 2012 American Vacuum Society. [DOI:10.1116/1.3660389]