기초과학융합연구소

•연구자: 물리학과 위상원, 이윤상

•발표일: 2024.03.05

•DOI: https://doi.org/10.1016/j.jallcom.2023.173102

•S.W. Wi et al., Journal of Alloys and Compounds (Q1);  Volume 976, 173102. (2024)

•Abstract

Recently, double perovskites oxides have emerged as a prominence in the luminescence research, attributed to their adaptable structure, diverse chemical compositions, and stability. In this work, we investigated intricate relationship between cation substitution-induced structural modifications and the luminescent properties of Eu³⁺ doped A₂LaNbO₆, where A represents Ba, Sr, and Ca. The structural transitions in the Eu³⁺-doped A₂LaNbO₆ system were identified through comprehensive structural analysis techniques, including X-ray diffraction and Rietveld refinement. Under both photo- and cathode-excitations, the emission properties of Eu³⁺ exhibited marked enhancements as the structural deformations increased. Particularly intriguing were the anomalies in emission intensities and distribution of emission spectra occurring near the structural transition. Furthermore, we explored the Eu³⁺ doping dependence of the structural and emission properties in Ca₂LaNbO₆. Notably, the photoluminescence quantum yield reached a fairly high value of 83% under 465 nm photoexcitation at the Eu³⁺ concentration of 0.5. Additionally, we demonstrated that integration of Eu³⁺-doped Ca₂LaNbO₆ into phosphor-based white light emitting diodes (WLEDs) lead to improvements in the correlated color temperature of WLEDs.