Investigation on photoluminescence and Judd-Ofelt parameters in Eu ion-doped CaZrO3 in relation to the local structural property

In this study, we investigated the photoluminescence (PL) of Eu ion-doped CaZrO3 in a wide doping concentration range (x = 0.005-0.1). The change in the local structure with Eu3+ doping was analyzed by employing Rietveld refinement on the X-ray diffraction patterns. X-ray photoemission spectroscopy revealed that the valence states of Eu ions are mainly trivalent in the CaZrO3 matrix for all doping concentrations. The emission spectra of our samples showed series peaks originating from the f-f transitions of Eu3+ ions in the red-orange region under ultraviolet photoexcitation. The time-resolved PL measurement demonstrated that the rising time decreased at higher x and that the average decay times were not affected by the doping concentration. The Judd-Ofelt parameters calculated from the PL spectra indicated that the asymmetry ratios changed nonmonotonically with the increasing doping concentration of Eu3+, which is in good agreement with the local lattice properties of our samples.