Annealing effect and photoluminescence properties in Tm+-implanted ZnO crystal

ZnO crystals were implanted by Tm+ ions at 500 keV with different doses at room temperature. The lattice damage tends to saturate at dose higher than 3 × 1015 ions cm−2, indicating a strong irradiation resistance of ZnO. Post-implant annealing at temperature from 800 to 1050 °C is performed to activate Tm ion optically. Annealing higher than 950 °C resulted in out-diffusion of Tm ions. Photoluminescence was measured at room temperature with UV and green excitation, luminescence of transition 3H4 → 3H6 from Tm3+ and concentration quenching behavior is observed in samples suffering 800 °C annealing for 30 min. Typical emission bands from ZnO crystal are detected in both virgin and the implanted samples. The results show that the implanted Tm+ seems serving as deep traps to contribute to the red band emission.