This study investigated ZnO nanowires, grown by different solutions of zinc nitrate and zinc acetate, using scanning electron microscopy, room-temperature photoluminescence, and X-ray photoelectron spectroscopy. ZnO grown by zinc nitrate had thinner nanowires, with the average diameter being reduced by about five times, than that grown by zinc acetate. Fewer surface defects and better electrical performance were obtained in zinc acetate-ZnO. The turn-on voltage and ideality factor were reduced from 2.2 to 2.0 V and 3.7 to 2.14, respectively, for the diodes grown by zinc nitrate and zinc acetate. Leakage current density was also decreased by about 1 order under 4 V reverse-bias voltage. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3478553] All rights reserved.