Second-phase-induced fluorescence quenching in non-equivalent substituted red phosphors

Jun Chen; Xianfeng Yang; Chunyan Jiang; Yunfeng Wang; Lei Zhou; Mingmei Wu

doi:10.1039/d2ra05647j

Second-phase-induced fluorescence quenching in non-equivalent substituted red phosphors

RSC Adv. 2022 Oct 21;12(45):29338-29345. doi: 10.1039/d2ra05647j. eCollection 2022 Oct 11.

Authors

Jun Chen¹, Xianfeng Yang², Chunyan Jiang¹, Yunfeng Wang^{1

3}, Lei Zhou¹, Mingmei Wu¹

Affiliations

¹ School of Chemistry/School of Marine Science/School of Chemical Engineering and Technology, Sun Yat-Sen University Guangzhou 510275/Zhuhai 519082 P. R. China wangyunfeng@nyist.edu.cn zhoul8@mail.sysu.edu.cn ceswmm@mail.sysu.edu.cn.
² Analytical and Testing Center, South China University of Technology Guangzhou 510640 P. R. China.
³ School of Information Engineering, Nanyang Institute of Technology Nanyang 473004 P. R. China.

Abstract

Concentration quenching, which generally originates from serious energy migrations among the uniformly distributed luminescent centers in the host matrix, is a key factor to influence the luminescence properties of materials. Different from previous reports, we demonstrate a novel fluorescence-quenching mechanism attributable to the second-phase Eu₂W₂O₉ in non-equivalent substituted SrWO₄:xEu³⁺ phosphors. The crystal structure, elemental distribution, and luminescence properties of the as-prepared SrWO₄:xEu³⁺ phosphors are systematically investigated. A second-phase Eu₂W₂O₉ is confirmed when the Eu³⁺-doping concentration exceeds 20%, which produces the new structure defects and energy-transfer paths, resulting in fluorescence quenching in this material. This finding gives a new perspective to analyze the concentration-quenching mechanism of the non-equivalent substituted phosphors and can help in the design of new, efficient luminescence materials. In addition, the as-prepared SrWO₄:xEu³⁺ phosphors exhibit a strong intrinsic excitation in the range of 355-425 nm, which is accompanied by the Commission Internationale de I'Eclairage (CIE) coordinates at (0.653, 0.347) and stable color purity of up to 94.52%. A packaged white light-emitting diode with CIE chromaticity coordinates of (0.398, 0.335), correlated color temperature of 3132 K, and color rendering index of 84.3 is fabricated by SrWO₄:20%Eu³⁺ phosphors with blue BAM:Eu²⁺ and green YAGB:Tb³⁺ phosphors in a near-ultraviolet chip.