Industrial high-rate (∼14 nm/s) deposition of low resistive and transparent ZnOx:Al films on glass

Aluminum doped ZnOx (ZnOx:Al) films have been deposited on glass in an in-line industrial-type reactor by a metalorganic chemical vapor deposition process at atmospheric pressure. Tertiary-butanol has been used as oxidant for diethylzinc and trimethylaluminium as dopant gas. ZnOx:Al films can be grown at very high deposition rates of ∼14 nm/s for a substrate speed from 150 to 500 mm/min. The electrical, structural (crystallinity and morphology) and optical properties of the deposited films have been characterized by using Hall, four point probe, X-ray diffraction, atomic force microscope and spectrophotometer, respectively. All the films have c-axis, (002) preferential orientation and good crystalline quality. ZnOx:Al films are highly conductive (R<9 Ω/sq, for a film thickness above 1300 nm) and transparent in the visible range (>80%). These results show that ZnOx:Al films with good electrical and optical properties can be grown with a high throughput industrial CVD process at atmospheric pressure. First p–i–n a-Si:H solar cells have been deposited on this material, with initial efficiency approaching 8%.