Synthetic process and luminescence properties of Er3+, Yb3+ doping fluoride-based up-conversion phosphors

Abstract

Fluoride-based doped Er3+, Yb3+ up-conversion (UC) luminescent materials were prepared via a traditional high-temperature solid-phase method. The optimum sintering temperature and holding time of phosphors were 625 °C and 1.5 h, respectively. When the molar ratio of Er3+/Yb3+ is 1:9, the phosphor shows the highest luminescence intensity. Simultaneously, NaF is used as the charge compensator and flux, which has vital effects on the luminescent properties; when the doping amount is 15 at.%, the luminescence intensity reached a maximum. The UC emission spectra of samples compose with three emitting peaks under the excitation of a 980 nm laser, including two green color-emitting peaks with a strong emission at 540 nm and a weaker emission at 521 nm and a red color emitting peak at 651 nm corresponding to the 4S3/2 → 4I15/2, 2H11/2 → 4I15/2, and 4F9/2 → 4I15/2 transitions of Er3+ ions, respectively. The optimal CIE coordinate of the phosphor is (0.2925, 0.6896). These results indicate that solid solution green UC phosphors with higher purity was synthesized. These results indicate that due to the excellent physical and chemical stability of fluoride-based doped Er3+, Yb3+ solid solution up-conversion phosphors, it may have potential applications in display devices, optical communications, and biosensors.