Title:New strategy for designing orangish-redemitting phosphor via oxygen-vacancy-induced electronic localization
Author(s):Wei, Yi; Xing, Gongcheng; Liu, Kang; Li, Guogang; Dang, Peipei; Liang, Sisi; Liu, Min; Cheng, Ziyong; Jin, Dayong; Lin, Jun*
Addresses:, China Univ Geosci, Fac Mat Sci & Chem, Engn Res Ctr Nanogeomat, Minist Educ, 388 Lumo Rd, Wuhan 430074, Hubei, Peoples R China
Source:Science & Applicationsvolume 8, Article number: 15 (2019)
Abstract: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.
Full Text from Publisher:https://www.nature.com/articles/s41377-019-0126-1
Photoluminescence properties and thermal stability analysis.