The optical properties of amorphous indium zinc oxide (a-IZO) films that were grown at room temperature by the pulsed laser deposition technique with the aid of a KrF excimer laser were investigated. Two values of 0.65 and 0.90 for the In/(In + Zn) films composition were chosen since they roughly define the area in the In-Zn-O phase diagram where good transmission in the visible range together with excellent electrical properties for a-IZO films were measured. The results of the investigations indicated that the IZO films containing 90 at.% In possessed excellent qualities: high transparency from 0.400 to 4 mu m, high reflectivity in the mid IR range together with a very low resistivity of 5 X 10(-4) Omega cm and a high mobility of 40 cm(2)/V s.