Discharge power dependence of structural and electrical properties of Al-doped ZnO conducting film by magnetron sputtering (for PDP)

In order to investigate the possible application of ZnO films as a transparent conducting oxide (TCO) electrode for AC PDP, ZnO:Al films were prepared by DC magnetron sputtering method. The effects of discharge power and doping concentration on the structural and electrical properties of ZnO films were mainly studied experimentally. Five-inch PDP cells using either a ZnO:Al or indium tin oxide (ITO) electrode were also fabricated separately under the same manufacturing conditions. The luminous properties of both the PDP cells were measured and compared with each other.By doping the ZnO target with 2 wt% of Al₂O₃, the film deposited at a discharge power of 40 W resulted in the minimum resistivity of 8.5 × 10⁻⁴ Ω-cm and a transmittance of 91.7%. However, a high doping concentration of 3 wt% of Al₂O₃ and excessive sputtering power over 40 W may induce high defect density and limit the growth of small grains. Although the luminance and luminous efficiency of the cell using ZnO:Al are lower than those of the cell with the ITO electrode by about 10%, these values are sufficient enough to be considered for the normal operation of AC PDP.