Iridium oxide (IrO2) thin films were prepared on Si (100) and quartz glass Substrates by pulsed laser deposition (PLD) technique. Electrical and optical properties, as well as morphology of annealed IrO2 thin films in air ambient were investigated by using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), four-point probe method, and ultraviolet-visible spectrometer. The results showed that the surface morphology of IrO2 thin films became denser and compact after being annealed at 600-800 degrees C for 30 min, while the surface roughness changed little. The room-temperature electrical resistivity of IrO2 films slightly decreased after being annealed at 600-750 degrees C and showed a minimum electrical resistivity of (38 +/- 3) mu Omega cm at 750 degrees C. The average transmittance of annealed IrO2 thin films (thickness: 65 nm) in the visible range was increased to almost 85-88%. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.