Fluorescence emission properties of Ni-doped ZnO films

Ni-doped ZnO films were deposited on Si(100) by pulsed laser deposition(PLD) at room temperature. Fluorescence emission properties of the films were measured using VARAIN Cary-Eclips 500 fluorescence spectrum analyzer. Two peaks centered respectively at about 360 and 380 nm were observed. The origin of the ultraviolet peak at 360 nm was investigated through doping Ni into the ZnO films. It was found that the intensity of this ultraviolet peak changed with Ni content while its position remained stable. The fluorescence emission of the samples was optimal when Ni : ZnO was 5 mol%, indicating that the peak centered at 360 nm might originate from the composite transition between the splitting valence band and conduction band, not from the entrance of the impurity energy level into the conduction band after doping.