Growth of pagoda-topped tetragonal copper nanopillar arrays.

Growth of arrays of pagoda-topped tetragonal Cu nanopillar (length 1− 6 μm; width 150 ± 25 nm) with {100} side faces on Au/glass is achieved by a simple electrochemical reduction of CuCl2(aq) by Al(s) in aqueous dodecyltrimethylammonium chloride. Field-emission measurement shows that the Cu nanopillars can emit electrons (10 μA cm−2) at a turn-on field of 12.4 V μm−1 with a calculated field enhancement factor of 713.