Study of ZnO : Al thin films prepared by ArF excimer laser ablation

Thin films of aluminum doped zinc oxide (ZnO:Al) have been deposited on qua rtz/corning glass substrate by pulsed laser deposition technique using ArF excimer laser (lambda =193 nm) at room temperature. To grow the films, a re petition rate of 10 Hz, an energy density of 2-3 J/cm(2) and an irradiation time of 10-60 min (6000-36000 shots) were maintained. The electrical and o ptical properties were found to depend on irradiation time. It was observed that thickness and optical transmittance of the ZnO:Al increased and band gap decreased with the increase of number of laser shots. X-ray diffraction analysis showed that the crystallinity and grain size of the film improved with increase in number of laser shots. The films are found to be strongly c-axis oriented polycrystalline having a resistivity of 1.21x10(-3) Ohm -C m for as grown films and a transmittance of 90-95% in the visible region. I n these pulsed laser deposited films, transmittance is found to be better t han those obtained by other deposition techniques such as RF and DC Magnetr on sputtering, chemical vapour deposition, sol gel and spray pyrolysis.