Properties of transparent,conducting ZnO films deposited by reactive bias sputtering

Transparent ZnO thin films of resistivity 2×10^?3 Ωcm have been prepared by a reactive bias sputtering technique. Carrier concentration and mobility were determined by Hall probe measurements. Microstructure and grain size were studied using a scanning electron microscope and an X-ray diffractometer. Optical constants were measured for the wavelength range 0.35 to 2.50 μm and infrared reflectivity for the range 2.5 to 20 μm. These optical properties were modelled by the Drude theory of free electrons utilizing measured electrical transport parameters.