기초과학융합연구소

•연구자: 물리학과 위상원, 이윤상

•발표일: 2022.10

•DOI:https://doi.org/10.1016/j.jre.2022.10.008

•S.W.Wi and Y.S.Lee, Journal of Rare Earths(Q1), Volume 42, Issue 1, Pages 66-75 (2024)

•Abstract

We investigated the emission properties of Eu³⁺-doped GdNbO₄-based oxide phosphors, aiming at improving the Eu³⁺ emission by codoping of Bi³⁺ and Li⁺. Eu³⁺ singly doped, Eu³⁺ and Bi³⁺ doubly doped, and Eu³⁺, Bi³⁺, and Li ⁺ triply doped GdNbO₄ were prepared using a high-temperature solid–state reaction method. The red-orange emissions from Eu³⁺ in the singly doped samples were significantly improved by the codoping of Bi³⁺, mainly due to the energy transfer from Bi³⁺ to Eu³⁺. The additional codoping of Li⁺ is found to increase the Eu³⁺ emission significantly. This improvement might be attributed to the increase in the photoluminescent quantum yield originating from larger grain sizes and better crystallinity. A detailed analysis of the X-ray diffraction pattern and the asymmetric ratio estimated from the Photoluminescence spectra show that the local lattice environment around Eu³⁺ in GdNbO₄ does not change significantly with the codoping of Bi³⁺ and Li⁺. Our results indicate that Li⁺ doping is a promising way to improve the emission properties of rare-earth ion-doped GdNbO₄ phosphors.