Crystal structure and optical properties of white light-emitting Y sub(2)WO sub(6):Sm super( 3+) phosphor with excellent color rendering

A new single-phased white light-emitting phosphor, Y sub(2)WO sub(6):Sm super( 3+), was synthesized viaconventional solid-state reaction calcining in air. The Y sub(2)WO sub(6):Sm super( 3+) samples were characterized using powder X-ray diffraction and refined with Rietveld methods. The phosphors exhibit a green emission from the host as well as a red emission from the dopant under ultraviolet excitation (300-380 nm). The color coordinates can be gradually tuned from green (0.247, 0.380) through white-light (0.319, 0.382) toward orange (0.335, 0.390) in the visible spectral region by systematically changing the Sm super(3+) dopant concentration. In addition, combining a 365 nm near-ultraviolet chip and Y sub(2)WO sub(6):0.02Sm super(3+) phosphor produced a white light-emitting diode, which exhibited an excellent color rendering index (Ra) of 92.3, a correlated color temperature of 5916 K and CIE coordinates of x= 0.3246, y= 0.3242.