Synthesis, Persistent Luminescence, and Thermoluminescence Properties of Yellow Sr3SiO5:Eu2+, RE3+ (RE=Ce, Nd, Dy, Ho, Er, Tm, Yb) and Orange-Red Sr3-xBaxSiO5:Eu2+, Dy3+ Phosphor

Sunlight-excitable orange or red persistent oxide phosphors with excellent performance are still in great need. Herein, an intense orange-red Sr3-xBaxSiO5:Eu2+,Dy3+ persistent luminescence phosphor was successfully developed by a two-step design strategy. The XRD patterns, photoluminescence excitation and emission spectra, and the thermoluminescence spectra were investigated in detail. By adding non-equivalent trivalent rare earth co-dopants to introduce foreign trapping centers, the persistent luminescence performance of Eu2+ in Sr3SiO5 was significantly modified. The yellow persistent emission intensity of Eu2+ was greatly enhanced by a factor of 4.5 in Sr3SiO5:Eu2+,Nd3+ compared with the previously reported Sr3SiO5:Eu2+, Dy3+. Furthermore, Sr ions were replaced with equivalent Ba to give Sr3-xBaxSiO5:Eu2+,Dy3+ phosphor, which shows yellow-to-orange-red tunable persistent emissions from =570 to 591nm as x is increased from 0 to 0.6. Additionally, the persistent emission intensity of Eu2+ is significantly improved by a factor of 2.7 in Sr3-xBaxSiO5:Eu2+,Dy3+ (x=0.2) compared with Sr3SiO5:Eu2+,Dy3+. A possible mechanism for enhanced and tunable persistent luminescence behavior of Eu2+ in Sr3-xBaxSiO5:Eu2+,RE3+ (RE=rare earth) is also proposed and discussed.