The effect of Li+ ions on the luminescent properties of a single-phase white light-emitting phosphor α-Sr2P2O7:Dy3+
Abstract
Two series of phosphors, α-Sr2(1−x)Dy2xP2O7 and α-Sr2(1−2x)Dy2xLi2xP2O7, with different x values were synthesized successfully using a conventional solid-state method at high temperature for the first time, and their luminescence properties were investigated comparatively. The effect of Li+ ions on the luminescence properties of Dy3+ in α-Sr2P2O7 host, including luminescence intensity, optimal doping concentration, concentration quenching mechanism, and decay behavior, was discussed in detail by considering the defect generation in α-Sr2P2O7:Dy3+, the charge compensation of Li+ ions and the role of Li2CO3 as solid flux expected in phosphors. The obtained excitation and emission spectra indicate that these as-prepared phosphors can be excited by ultraviolet light and show white light emission due to the combination of the 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions of Dy3+ ions. The CIE chromaticity coordinates and color correlated temperature of Dy3+ emission in the phosphor α-Sr2(1−2x)Dy2xLi2xP2O7 (x = 0.03) with optimal fluorescence intensity was also calculated. The present work could be helpful for understanding the effect of the charge compensator (e.g. Li+ ion) on the luminescent properties of phosphors with non-equivalent ion-displacement and the design of novel phosphors by efficiently taking advantage of charge compensator (e.g. Li+ ion).