Highly arrayed nitrogen-doped ZnO nanorods were fabricated on Si buffered with ZnO film by combining wet-chemical process with post-treated by NH3 plasma. The X-ray photoelectron spectroscopy measurement demonstrates that the nitrogen-doped ZnO nanorods have been formed due to nitrogen diffusion through surface adsorption or defect routes. The photoluminescence spectra indicate that a strong UV emission peak around 3.31 eV with negligible deep level emission can be obtained for the nitrogen-doped ZnO nanorods compared to that of the untreated sample. The I-V measurements indicate that the p-type ZnO nanorods with a smaller threshold voltage of 1.5 V can be obtained. (C) 2005 Elsevier B.V. All rights reserved.