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

• Main Authors: Illiberi, A., Kniknie, B., van Deelen, J., Steijvers, H. L. A. H., Habets, D., Simons, P. J. P. M., Janssen, A. C., Beckers, E. H. A.
• Format: Conference Proceeding
• Language: English
• Subjects: Conductivity; Glass; Photovoltaic cells; Substrates; Zinc oxide
• ISSN: 0160-8371
• DOI: 10.1109/PVSC.2011.6186688

The results presented in this paper show that highly conductive and transparent ZnO x :Al films can be grown on glass by a high throughput industrial CVD process at atmospheric pressure. Amorphous silicon p-i-n solar cells have been grown on as deposited ZnO x :Al films in order to demonstrate the suitability of this material as front contact for thin silicon film solar cells. Aluminum doped ZnO x (ZnO x :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. ZnO x :Al films can be grown at very high deposition rates of ~ 14 nm/s for a substrate speed from 150 mm/min 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. ZnO x :Al films are highly conductive (R ; 80%). Amorphous silicon p-i-n solar cells have been grown on as deposited ZnO x :Al films, without optimizing the surface texturing of ZnO x :Al films to enhance light scattering. An initial efficiency of approximately 8% has been achieved.