Temperature-induced luminescence enhancement and quenching behavior of Eu3+ in Lu2(WO4)3 phosphors

The Eu3+-doped Lu2(WO4)3 phosphors were prepared via a solid-state reaction approach at different calcination temperatures. The synthesized phosphors were extensively characterized using different techniques to understand the structure, the composition, the morphology, and the photoluminescence (PL) properties. Subsequently, the red phosphors were incorporated into lighting emitting diode (LED) devices in combination with near-ultraviolet (n-UV) 397 nm chips. At measuring temperature of 170 °C, the Eu3+-doped Lu2(WO4)3 phosphors exhibited thermal enhancing luminescence when excited by a charge transfer band (CTB). Conversely, under intra 4f-4f excitation at 396 or 397 nm, the phosphors demonstrated thermal quenching luminescence. The possible reasons were discussed based on the experimental results and some references. The observed thermal enhancing luminescence is advantageous for mitigating the effects of thermal quenching.