Crystal structure and optical properties of white light-emitting Y2WO6:Sm3+ phosphor with excellent color rendering

Abstract

A new single-phased white light-emitting phosphor, Y₂WO₆:Sm³⁺, was synthesized via conventional solid-state reaction calcining in air. The Y₂WO₆:Sm³⁺ 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 Sm³⁺ dopant concentration. In addition, combining a 365 nm near-ultraviolet chip and Y₂WO₆:0.02Sm³⁺ 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.