Journal of Inorganic Materials, Volume. 40, Issue 3, 314(2025)
Violet light excited white light emitting diodes (LEDs) have attracted widespread attention due to their advantages of tunable color temperature and visual comfort. However, high-performance phosphors suitable for violet light excitation (400-420 nm) have not yet been widely applied on a large scale. One of the key factors regarding the commercial utilizations is the stability. Unfortunately, there still lacks research on this issue. In this study, three rare-earth phosphors suitable for violet light excitation in LEDs were synthesized via a solid-state reaction method, namely K2CaPO4F:Eu2+, K1.3Al11O17+δ:Eu2+ and Ca2YHf2Al3O12:Ce3+,Tb3+. The stability experiments were then conducted under conditions of high temperature and humidity, water immersion, and long-term violet light irradiation from LED chips. The luminescent properties, failure mechanisms, and environmental stability were analyzed. Finally, a white LED device was prepared by combining the as-synthesized three phosphors onto a 400 nm violet light chip. Results demonstrate that the as-synthesized phosphors exhibit not only optimized luminescence performance compared to phosphors prepared in former works, but also a more comprehensive evaluation of environmental stability across different conditions. The white LED device achieves a color rendering index of 93.6, a correlated color temperature of 5151 K and a color coordinate of (0.34, 0.36), showcasing excellent white light illumination performance. Furthermore, the environmental stability of the white LED device is improved compared to individual phosphors. By taking lead in investigating the environmental stability of violet light excited LED phosphors, this work provides valuable insights and guidance for advancing their applications.
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Zesheng PAN, Yaping YOU, Ya ZHENG, Haijie CHEN, Lianjun WANG, Wan JIANG.
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Received: Aug. 30, 2024
Accepted: --
Published Online: Apr. 24, 2025
The Author Email: CHEN Haijie (haijie.chen@dhu.edu.cn), WANG Lianjun (wanglj@dhu.edu.cn)