White LEDs using the sharp β‐sialon: Eu phosphor and Mn‐doped red phosphor for wide‐color gamut display applications

Abstract The sharp β‐sialon (Si 6‐z Al z O z N 8‐z : 0 < z < 0.1):Eu green phosphor, combining with a blue LED and CaAlSiN 3 :Eu red phosphor, is suitable for the wide‐color gamut white LEDs backlighting system, because of its sharp and asymmetric emission spectrum shape. However, the color gamut and the brightness of the aforementioned display is restricted because of the wide emission band of the CaAlSiN 3 :Eu red phosphor. In this work, we used K 2 SiF 6 :Mn as an alternate red phosphor, which has a sharp emission spectrum. The display with the white LED using sharp β‐sialon:Eu and K 2 SiF 6 :Mn shows a wide‐color gamut, which covers the hole NTSC triangle. The use of K 2 SiF 6 :Mn enables to realize not only a wider color gamut but also a higher brightness of displays, compared with the use of CaAlSiN 3 :Eu. Furthermore, it is confirmed that the white LED using sharp β‐sialon:Eu and K 2 SiF 6 :Mn is stable against temperature and also durable under the accelerated drive conditions.