Thermoluminescence in ZrO2 with impurity of ZnO induced by UV radiation

ZrO₂ pellets doped by ZnO after 302 nm UV irradiation have been studied for ThermoLuminescent (TL) glow. The TL peak at 90°C for the 1100°C sintered ZrO₂ pellet shifted to 85°C with intensity increased three times for the 1% ZnO doped ZrO₂ sintered at 1100°C. The peak intensity at 210°C for the doped one is only one tenth of the undoped one. The emission spectra of thermoluminescence for undoped and ZnO-doped ZrO₂ revealed that the effect of ZnO doping is to increase the number of luminescent centers. The trapping center associated to the 90°C TL peak is explained by the similar model as that of Kirsh et al. For the case of 210°C TL peak, we have proposed two different models of trapping centers; one is the Zr⁴⁺ in an asymmetrical oxygen arrangement, and the other is the defect complex formed from an oxygen vacancy and an anion.