Deposition and Characterization of Transparent Thin Films of Zinc Oxide Doped with Bi and Sb

Undoped and Bi/Sb doped highly transparent ZnO films were grown adopting metal organic chemical vapor deposition with suitable combinations of Zn(C 5 F 6 HO 2 ) 2 ·2H 2 O·(CH 3 OCH 2 CH 2 ) 2 O, Bi(C 6 H 5 ) 3, and Sb(C 6 H 5 ) 3 precursors. Hexagonal ZnO phases were always found. Doping levels ranged from 1.4 to 7.4 and from 0.2 to1.8 atomic % for Bi and Sb, respectively. UV−vis measurements indicated that the film transmittance was usually as high as 90% in the visible and near-infrared region. Dopant surface segregation was found in X-ray photoelectron spectroscopy experiments. Preliminary resistivity measurements indicated that lightly doped ZnO films are semiconducting while greater doping levels could result in potential varistor properties.