Photoluminescence properties of Eu3+ doped ZrO2 with different morphologies and crystal structures

Eu3+-doped ZrO2 nanotube arrays and Eu3+-doped ZrO2 nanoparticles were prepared by anodisation of the Zr-Eu alloy and by chemical co-precipitation method, respectively. The effects of anodisation conditions and annealing temperature on the morphology, crystalline phase and properties of Eu3+-doped ZrO2 nanotube arrays were studied. The photoluminescence (PL) excitation and emission spectra of different samples were compared and the related reasons were discussed. Results show that the crystal structures of ZrO2 nanotube arrays prepared in organic (Eu-ZNTA-o) or water (Eu-ZNTA-w) solution and the Eu3+-doped ZrO2 nanoparticles (Eu-ZP) are much different. When annealed at 600 degrees C, the ZrO2 nanotube arrays contain both tetragonal and monoclinic phases (with only 5.9% of tetragonal phase for Eu-ZNTA-o and 64.1% tetragonal ZrO2 for Eu-ZNTA-w), while the Eu3+-doped ZrO2 nanoparticles are pure tetragonal phase. The PL emission spectra of Eu-ZNTA-o and Eu-ZP are significantly different. The PL emission spectra of Eu-ZNTA-w approximate the superposition of the former two. Compared with the tetragonal phase, the monoclinic phase matrix is more favorable to the absorption and transfer of energy. In addition, the morphology of the sample can lead to lattice distortion, which can also have an effect on the photoluminescence properties. (C) 2021 Elsevier B.V. All rights reserved.