Effect of excimer laser annealing on the properties of ZnO thin film prepared by sol-gel method

Pristine ZnO thin films have been deposited with zinc acetate [Zn(CH3COO)2], mono-ethanolamine (stabilizer), and isopropanol solutions by sol-gel method. After deposition, pristine ZnO thin films have been irradiated by excimer laser (λ = 248, KrF) source with energy density of 50 mJ/cm2 for 30 sec. The effect of excimer laser annealing on the optical and structural properties of ZnO thin films are investigated by photoluminescence and field emission scanning electron microscope. As-grown ZnO thin films show a huge peak of visible region and a wide full width at half maximum (FWHM) of UV region due to low quality with amorphous ZnO thin films. After KrF excimer laser annealing, ZnO thin films show intense near-band-edge (NBE) emission and weak deep-level emission. The optically improved pristine ZnO thin films have demonstrated that excimer laser annealing is novel treatment process at room temperature.

► We have investigated the effects of KrF excimer laser annealing on thin films.
► After laser annealing, ZnO thin films show that blue-green emission is decreased.
► Excimer laser annealing is good treatment process to increase the crystal quality.
► Finally, KrF excimer laser annealing is good candidate of low temperature process.