Effect of Pr doping on structure and luminescence properties of ZrO2 nanoparticles

Abstract Pr 3+ impurity transitions in monoclinic and cubic phases of ZrO 2 have been investigated by photoluminescence and thermoluminescence (TL). Zr (1− x ) Pr x O 2 (0 ⩽ x ⩽ 0.015) samples were prepared by the combustion method. Rietveld refined x-ray diffraction results confirm that undoped ZrO 2 has a monoclinic structure, whereas Pr doped ZrO 2 samples are in mixed phase consisting of monoclinic and cubic structures. ZrO 2 shows a broad defect-related emission peak centered at 500 nm under an excitation wavelength of 300 nm. A series of Pr 3+ -related emissions are observed at 512, 584, 612–640 nm due to 3 P 0 → 3 H 4 , 3 P 1 + 1 I 6 → 3 H 5 , 1 D 2 → 3 H 4 transitions and between 719 and 740 nm due to 1 D 2 → 3 H 5 transitions when excited with 454 nm. The PL decay lifetime of Zr 0.996 Pr 0.004 O 2 is 1.55 μ s for fixed λ ex = 300 nm and λ em = 612 nm. The TL glow curve of Zr 0.99 Pr 0.01 O 2 shows a prominent peak at 695 K and secondary peaks at 508 K and 570 K, which are not observed in undoped ZrO 2 . The TL emission measured at 695 K confirms that Pr 3+ replaces Zr 4+ in cubic lattice sites of ZrO 2 . This work shows the relationship between the luminescence properties and different structures of ZrO 2 and that supports the design of new materials for possible applications.