ZnO nanorod light-emitting diodes fabricated by electrochemical approaches

We report simple electrochemical methods for rapid growth of freestanding wurtzite ZnO nanorods in an aqueous solution and the following fabrication of a ZnO nanorod/poly(3-methylthiophene) heterojunction light-emitting diode. The typical electroluminescence spectra obtained from this heterostructure device under forward bias show a strong ultraviolet peak and a weak visible emission. The emission of the heterostructure device is much stronger than that of the ZnO-only structure and the turn-on voltage is about 7 V. (C) 2007 Elsevier B.V. All rights reserved.