In copolymer phosphors with Eu(III), the majority have difficulty in resisting aging by UV light. In this paper, a novel copolymer phosphor with high thermal resistance and good ultraviolet aging… Click to show full abstract
In copolymer phosphors with Eu(III), the majority have difficulty in resisting aging by UV light. In this paper, a novel copolymer phosphor with high thermal resistance and good ultraviolet aging resistance was synthesized by radical polymerization from the Eu-complex and siloxane. Intense red emission peaked at 613 nm, corresponding to the 5D0 → 7F2 transition of Eu(III) ions, was observed under UV excitation. The fluorescence lifetime is calculated as 0.586 ms, with a loss of 0.003 ms after aging for 150 h. The thermal stability shows excellent resistance to high temperature, and the initial decomposition temperature is 153 °C, which meets the requirement of LED operating temperature. The CIE of the LED device is (0.625, 0.308) under excitation at 365 nm. The LED device fabricated with the copolymer and a near-UV LED chip shows bright pure-red emission and good resistance to UV aging. This shows that the copolymer phosphor can be used as an efficient red phosphor in WLEDs.
               
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