Nb-doped ZnO thin films have been prepared on glass substrates by pulsed laser deposition (PLD). The effect of substrate temperature has been investigated from 100 to 500 degrees C by analyzing the structural, optical, and electrical properties. The Nb-doped ZnO films possessed a good crystallinity with a c-axis preferential orientation and a high transmittance (above 85%) in the visible region. The obtained film deposited at 350 degrees C exhibited the best electrical properties with the lowest room-temperature resistivity of around 5 x 10(-4) Omega cm. Guided by x-ray photoemission spectroscopy analysis, Nb-Zn(3+) is believed to be the very possible donor in the Nb-doped ZnO films. (C) 2009 Elsevier B.V. All rights reserved.