Investigation of a novel Pr3+-activated LiYGeO4 phosphor with red long-persistent luminescence

Here, we have synthesized a novel LiYGeO4:Pr3+ phosphor with red persistent luminescence (PersL) by con-ventional high-temperature solid-state method. LiYGeO4:0.15%Pr3+ emits a bright red PersL, which lasts for more than 1500 s after 254 nm UV lamp pre-irradiated for 10 min. The photoluminescence (PL) and PersL spectra both exhibit UV (-353 nm) and red (-601 nm) emissions, which originate from the self-trapped exci-tation (STE) of the matrix and the 1D2 -> 3H4 electron transition of Pr3+, respectively. Additionally, a series of PersL and thermoluminescence (TL) measurements were conducted to investigate the properties of PersL. It was concluded that with the incorporation of Pr3+, more shallow traps are introduced into the material which is conducive to improve the PersL performance at ambient temperature. Moreover, the material exhibits excep-tional color purity, which is a good choice as a red PersL material. In the end, we propose a plausible mechanism to elucidate the red PersL phenomenon.