Luminescence and energy transfer of Tm3+ or/and Dy3+ co-doped in Sr3Y(PO4)3 phosphors with UV excitation for WLEDs

Powder samples Sr3Y1-x-y(PO4)(3):xTm(3+)-yDy(3+) were synthesized by the conventional solid-state reaction method. By appropriate tuning of activator content, the emission color can be adjusted around blue to white and yellow. It was discovered that the energy transfer from Tm3+ to Dy3+ was demonstrated to be via the intensity of Dy3+ emission increase with the increase of Tm3+ concentration. By changing the doping concentration of Tm3+ and Dy3+ in Sr3Y(PO4)(3), white-emitting phosphors are produced by 350 nm excitation wavelength, their corresponding color coordinates are very close to the white color chromaticity coordinates (x=0.33, y=0.33). Finally, Sr3Y1-x-y(PO4)(3):xTm(3+)-yDy(3+) phosphors could be a good promising single-component white light-emitting UV-convertible phosphor in the field of white LEDs. (C) 2013 Elsevier B.V. All rights reserved.