White Light-Emitting Diodes for Wide-Color-Gamut Backlight Using Green-Emitting Sr-Sialon Phosphor

We have successfully developed a white light-emitting diode (LED) for a wide-color-gamut backlight composed of a green-emitting phosphor Sr3Si13Al3O2N21:Eu2+ combined with a blue LED and a red-emitting phosphor CaAlSiN3:Eu2+. This white LED showed a discrete spectrum with distinct separation of red, green, and blue primary colors due to a narrow emission band of around 525 nm for the green phosphor. 94.2% of the wide color gamut of the National Television System Committee standard was attained by applying typical color filters of LCDs. The power LED module composed of 16 of these white LEDs revealed their excellent power dependence. The LED is expected to replace cold cathode fluorescent lamp (CCFL), and find a suitable application as a backlight in large-scale LCDs for in-vehicle use or for flat-panel television sets.