New strategy for designing orangish-red-emitting phosphor via oxygen-vacancy-induced electronic localization

作者：Yi Wei, G. Xing, Kang Liu, Guogang Li, Peipei Dang, Sisi Liang, Min Liu, Ziyong Cheng, D. Jin, Jun Lin · 发表于：Light: Science & Applications · 年份：2019 · DOI：10.1038/s41377-019-0126-1 · 被引用次数：308 · 研究领域：Medicine

Phosphor-converted white-light-emitting diodes (pc-WLED) have been extensively employed as solid-state lighting sources, which have a very important role in people’s daily lives. However, due to the scarcity of the red component, it is difficult to realize warm white light efficiently. Hence, red-emitting phosphors are urgently required for improving the illumination quality. In this work, we develop a novel orangish-red La4GeO8:Bi3+ phosphor, the emission peak of which is located at 600 nm under near-ultraviolet (n-UV) light excitation. The full width at half maximum (fwhm) is 103 nm, the internal quantum efficiency (IQE) exceeds 88%, and the external quantum efficiency (EQE) is 69%. According to Rietveld refinement analysis and density functional theory (DFT) calculations, Bi3+ ions randomly occupy all La sites in orthorhombic La4GeO8. Importantly, the oxygen-vacancy-induced electronic localization around the Bi3+ ions is the main reason for the highly efficient orangish-red luminescence. These results provide a new perspective and insight from the local electron structure for designing inorganic phosphor materials that realize the unique luminescence performance of Bi3+ ions.LEDs: Painting the town redPhosphorescent substances that give white-light-emitting diodes a more natural reddish hue can be made by tuning the electron structure of their activator ions. Jun Lin of China’s Changchun Institute of Applied Chemistry, Chinese Academy of Sciences and colleagues combined ge...