[Synthesis and luminescence properties of Y10W2O21:Eu nanophosphor].

ABSTRACT

In the present paper, a novel nanophosphor, Y10W2O21Eu was synthesized through a simple and low-cost method: co-precipitation. The results of XRD show that resultant samples are Orthorhombic phase and primitive lattice. The average crystallographic sizes could be confirmed to be approximately 80 nm by means of the Scherrer formula, which are in good agreement with the particles sizes exhibited by SEM. In the excitation spectra of Y10W2O21Eu nanophosphor, by monitoring 610 nm, the charge transfer bands (CTB) of O--Eu and O--W, centering at around 270 and 307 nm, can be observed, respectively. The spectral lines shape and locations of excitation peak corresponding to 4f-->4f transitions are similar in all samples. But the relative intensity ratios between O--Eu and O--W CTB excitation peak increase with the Eu3+ doping concentration increasing. The characteristic red emission at around 610 nm of Eu3+ was also observed, ascribed to the (5)D0--(7)>F2 transition of Eu3+, and the optimal doping concentration is 20 mol%. Finally, the transition intensity parameters omega(lamda = 2,4) and the quantum efficiencies of (5)D0 level of Eu3+ were calculated according to Judd-Ofelt theory. The results indicate that Eu(3+5)D0-->(7)F2 610 nm red luminescence can be effectively excited by 394 nm near-UV light and 464 nm blue light in Y10W2O21 host, which is similar to the familiar Eu3+ doped tungstate (e.g., Gd2(WO4)3, CaWO4). Therefore, the Y10W2O21Eu red nanophosphors may have a potential application for white LED.