AVS 47th International Symposium
    Thin Films Thursday Sessions
       Session TF-ThA

Paper TF-ThA5
Expanding Thermal Plasma Deposition of Natively Textured ZnO for Thin Film Solar Cell Applications

Thursday, October 5, 2000, 3:20 pm, Room 203

Session: Transparent Optical Coatings
Presenter: R. Groenen, Eindhoven University of Technology, The Netherlands
Authors: R. Groenen, Eindhoven University of Technology, The Netherlands
J. Loeffler, Utrecht University, The Netherlands
J.L. Linden, TNO-TPD, The Netherlands
R.E.I. Schropp, Utrecht University, The Netherlands
M.C.M. van de Sanden, Eindhoven University of Technology, The Netherlands
Correspondent: Click to Email
A new approach for low temperature deposition of natively textured ZnO is developed, utilizing an expanding thermal argon plasma created with a cascaded arc. (Co)precursors are oxygen, diethylzinc and -additionally for doped films- trimethylaluminum, which undergo ionisation via charge exchange and consecutive dissociative recombination by respectively argon ions and electrons created in the arc. Films are deposited on Corning 1737 F glass at substrate temperatures of 200 - 350°C at a rate of 0.65 - 0.75 nm s@super -1@. The optical and electrical properties relevant for solar cell applications are comparable to those obtained for Asahi U-type SnO@sub 2@:F. Measurements of haze and angular resolved scattering intensity reveal increased light scattering with increasing deposition temperature and film thickness because of a rougher surface texture as confirmed by AFM and SEM measurements. In addition, virtually no loss in transmission of the ZnO films due to hydrogen plasma exposure is observed. In order to demonstrate the suitability for solar cell applications, p-i-n a-Si:H solar cells were co-deposited both on the natively textured low temperature material and Asahi U-type SnO@sub 2@:F, showing comparable efficiencies around 10%. The TCO / p-layer interface leads to effective light scattering, which results in high spectral response especially for long wavelengths.