A zero-thermal-quenching and color-tunable phosphor LuVO4: Bi3+, Eu3+ for NUV LEDs

Xinguo Zhang, Zhenpeng Zhu, Ziying Guo, Fuwang Mo, Zhan-chao Wu

Index: 10.1016/j.dyepig.2018.03.071

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Abstract

Thermal quenching is one of the most crucial challenges for LED phosphors, in which the phosphor in LED device suffers from emission loss due to non-radiative transition with increasing temperature. Here, we report a broadband-excited and color-tunable LuVO4: Bi3+, Eu3+ phosphor that does not exhibit thermal quenching even up to 200 °C. The phosphor shows Bi3+ absorption broadband ranging from 250 to 400 nm, along with the sensitized Eu3+ red emission lines. The emission color tuned from yellow with color coordinate (0.403, 0.507) to bright red (0.609, 0.370) as a function of Bi3+/Eu3+ ratio. The phenomenon of zero thermal quenching originates from enhanced energy transfer (ET) from Bi3+3P1 state to Eu3+5D4 state through the population inversion from 3P0 to 3P1 at high temperature. Due to strong UV absorption, high quantum efficiency (∼76%) and excellent thermal stability, the as-prepared LuVO4: Bi3+, Eu3+ phosphors can be potential candidates as red phosphors applied in UV-pumped LEDs.