Pulsed-laser deposited Er:ZnO films for 1.54μm emission

Abstract

High-quality Er:ZnO films were grown by the pulsed-laser deposition technique at high temperature followed by in situ annealing. The films demonstrate remarkable crystalline quality and array of self-assembled grains. Although the films show very low electrical resistivity (∼6.41×10−4Ωcm) at room temperature, a semiconductor-metal transition was observed at 190K for low doping in contrast to semiconductor behavior for high doping. The films show pronounced room temperature emission at 1.54μm, illustrating the activation of Er3+ ions in ZnO matrix. Furthermore, no quenching effects in 1.54μm emission characteristics were observed up to 2wt% of Er doping in ZnO at room temperature.