The luminescence properties of a novel oxynitride phosphor Sr3-yEuySiO5-6xN4x

A novel yellow-orange emitting oxynitride phosphor Sr3-yEuySiO5-6xN4x (0 <= x <= 0.35, 0.01 <= y <= 0.08) was prepared through solid-state reaction at 1550 degrees C and characterized by X-ray powder diffraction. The result indicates that all the major phase of synthesized phosphors is isostructural with Sr3SiO5. The excitation spectra (lambda(em) = 582 nm) and emission spectra (lambda(ex) = 460 nm) exhibit broadband character with main peak located at 363 nm and 581 to 585 nm, respectively. The effects caused by doping nitrogen on luminescence and thermal stability of the samples were studied. As the amount of nitrogen increases, the luminescence intensity and the thermal stability of the phosphor are both enhanced obviously. In comparison with of Sr2.97Eu0.03SiO5 (x = 0), the emission shifts to blue first (x = 0.06) and then to red with the x value increasing from 0.12 to 0.33. The concentration quenching occurs when y equals to 0.03 and the emission shifts to red light area as the concentration of Eu2+ ions increases. Under the 460 nm blue light excitation the external quantum efficiency of Sr2.97Eu0.03SiO3.02N1.32 reaches 51.99%, which illustrates that this novel oxynitride phosphor has a potential application in WLEDs. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.