Semiconducting ZnO nanowires have been produced in bulk quantity by heating Zn powders (99.99%) containing An nanoparticles at 900 degreesC. Scanning electron microscopy and transmission electron microscopy observations show that the ZnO nanowires have diameters ranging from 30 to 60 nm and lengths up to several tens of micrometers. The growth of ZnO nanowires is controlled by the conventional vapor-liquid-solid (VLS) mechanism. A green light emission was observed at room temperature, which could be attributed to the singly ionized oxygen vacancy formed in the ZnO nanowires. (C) 2002 Elsevier Science B.V. All rights reserved.