Photoluminescence properties of Eu3+:RbGd(WO4)(2) red phosphors prepared by sol-gel method

作者：Rasu K Kavi; Balaji D; Babu S Moorthy

来源：Journal of Luminescence, 2016, 170: 825-834.

DOI：10.1016/j.jlumin.2015.09.030

• Phosphor
• Double tungstate
• White LED
• Judd-Ofelt theory

RbGd(WO4)(2) (RGW) phosphors with different concentration of Eu3+ ions were synthesized by the modified sol-gel method. Powder X-ray diffraction (XRD) with structure refinement, Raman, scanning electron microscopy (SEM), high resolution transmission electron microscope (HR-TEM), photoluminescence (PL) and lifetime analysis were employed to characterize the synthesized phosphors. The crystal structure of RGW was refined and determined to be monoclinic system with the refinement converged to R-p=2.14%, R-wp=8.09%, and X-2=6.46 by Rietveld process. The excitation spectra consist of a broad charge transfer band from 240 to 350 nm and several other sharp peaks at around 360-550 nm due to f-f transition of Eu3+ ions. The phosphor exhibits strong red luminescence peak at 616 nm for D-5(0)-> F-7(2) transitions of Eu3+ ions excited under 395 nm. The critical distance was calculated to be 9.21 angstrom. In addition, Judd-Ofelt parameters of Eu3+ :RGW phosphor were obtained using the emission spectrum and the chromaticity coordinates were found to be (x=0.660, y=0.339). This is closer to the standard values of the National Television Standard Committee (x=0.67, y=0.33).

• 出版日期2016-2