Aluminum-doped ZnO (AZO) films have been deposited by room-temperature radio frequency (RF) magnetron sputtering onto fused-quartz substrates using a ZnO:Al 2 O 3 (98:2 wt.%) target. A post-deposition anneal in an N 2 flow has been shown to improve the electrical and optical properties of as-deposited AZO. All films were polycrystalline and exhibited a hexagonal wurtzite structure with the c-axis oriented perpendicular to the substrate. An increase in the estimated crystallite size was observed after annealing. Electrical resistivity was reduced from 3.7 9 10 À3 X cm for as-deposited layers to 7.1 9 10 À4 X cm for annealed films. An average optical transmittance >85% for annealed films was routinely measured. X-ray photoelectron spectroscopy measurements indicated that the surfaces of all layers investigated were oxygen deficient, and the density of oxygen vacancies was found to increase following the anneal.

No abstract

No abstract