Study on the Up-Conversion Luminescence and Conductivity Behavior of p-Type NiO:Yb,Er Thin Films

In this work, Li⁺-doped NiO:Yb,Er thin films are obtained via pulsed laser deposition. It was found that the films exhibit high transparency in the visible region and clearly red up-conversion luminescence under 980 nm excitation. Doping with Li⁺ can adjust the up-conversion emission intensity of the films. Moreover, all the films have p-type conductivity with a single activation energy of around 360 meV. The sheet resistivity of the films can be improved through changing the doping concentration of Li⁺ ions. Taken together, 5% is the best doping concentration for the potential application of this kind of film.