White light emission in host-sensitized Dy3+-single-doped NaIn(WO4)2 phosphors

A novel white NaIn1 - x(WO4)(2): xDy(3+) (x=0, 0.02, 0.04, 0.06 and 0.08) phosphors in pure phase were prepared via high temperature solid-state reaction, and luminescent properties of the phosphors were investigated. The crystal structure of the phosphor was characterized by powder X-ray diffraction, and the spectroscopic properties of Dy3+-doped NaIn(WO4)(2) were investigated by diffuse reflectance spectra, photoluminescence e mission and photoluminescence excitation spectroscopy. Those spectra illustrated that the Dy3+-doped NaIn(WO4)(2) phosphors could be efficiently excited by the host-sensitized excitation in the spectral range of 280-350 nm, and the host-sensitized excitation is more efficient than the Dy3+-excitation. The 6 mol% Dy3+ doping concentration in NaIn(WO4)(2) is optimum, and the luminescence concentration quenching occurs beyond the 6 mol% concentration. The concentration quenching mechanism could be attributed to the dipole-dipole interaction between the Dy3+ ions. The CIE color coordinate of the 6 mol% Dy3+-doped NaIn(WO4)(2) is (0.319, 0.325). The present work suggests that Dy3+-doped NaIn(WO4)(2) could be a promising host-sensitized phosphor applied in white LEDs, and white emission can be obtained by combining the blue host emission with the yellow Dy3+-emission. (C) 2014 Elsevier B.V. All rights reserved.