Recent Progress in Blue Phosphors: From Non-Thermal Quenching to Highly Efficient Phosphor

In the present era of solid-state lighting, white light-emitting diodes (WLEDs) have received enormous attention as general lighting source due to its energy efficiency and environmental friendly technology. However, the current high power WLED faces serious challenge of luminescence loss of phosphor due to the generation of heat under operation and at elevated temperature known as thermal quenching. Therefore, it is highly desirable to find new phosphors with high efficiency and thermal stability.

Hence, our search for a new and efficient phosphor host, has led to the emergence of oxohalide/oxide host with very high PL and conversion efficiency. In this talk, some works from our laboratory on the recent progress in blue-emitting phosphors are summarized. In particular, new NASICON based blue-emitting phosphor shows negligible thermal quenching for WLED applications, which exhibited broad blue emission under near UV excitation and retains its luminescence at elevated temperature of 473 K. Also, some blue-emitting phosphors with their excellent optical properties are reported.^1,2

References
[1] S. J. Gwak, P. Arunkumar, and W. B. Im, J. Phys. Chem. C, Vol.118, pp. 2686-2692, 2014.
[2] Y. H. Kim and W. B. Im, Opt. Lett., Vol.39, pp. 4887-4890, 2014.