Abstract: Al-Ti codoped ZnO (ZATO) films with (100) preferred orientation were grown on the glass substrates at room temperature by RF magnetron sputtering. The Al-Ti codoped ZnO ceramic targets used for sputtering were prepared by the conventional solid-state sintering process. The growth mechanism, microstructures and surface figures of ZATO films were investigated by X-ray diffraction (XRD) and scanning electronic microscope (SEM), and its optical and electrical properties were respectively measured using a four-point probe technique and UV-756 spectrophotometer at room temperature. After the ZATO films annealed at 500℃ for 3h, the preferred growth orientation of the films changes from (002) to (100) orientation, and the optic band gap reduces from 3.29eV to 2.86eV, and the average transmittance reduces from 90% to 70%, but the room-temperature resistivity reduces from 1.89×10^-2Ω·cm to 1.25×10^-3 Ω·cm. And at the same time, there is a super-lattice diffraction ray in the XRD patterns of annealed the ZATO films. The photoluminescence (PL) spectra confirm that there exhibit the near-band-edge (NBE) emission peaks at 380nm, and 410nm, 564nm PL peaks of all the films. After the films are annealed at 500℃ for 3h, the strength of these PL peaks drops, but its positions change little. The above experimental mechanisms were discussed.

Key words: ZnO thin films, Ti-Al codopant, [100] orientation, photoelectric properties