Preparation and optical properties of Bi doped ZnO thin films with (100) orientation by rf magnetron sputtering

Bi doped ZnO films with (100) orientation have been grown on glass substrates by rf magnetron sputtering followed by vacuum annealing at 400 A degrees C for 3 h. X-ray diffraction (XRD) revealed that the film first growth along (002) direction was suppressed to form (100) plane with c-axis parallel to the substrate. After annealed at 400 A degrees C for 3 h under vacuum, transmittance about 80% in visible region and near 100% absorption in UV region for (100) oriented Bi doped ZnO films are confirmed by the optical transmission spectra. The optical band gap is evaluated to be around 3.13 eV which is lower than (002) oriented films.