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

• A novel phosphor Sr3−yEuySiO5−6xN4x was prepared by solid-state reaction.
• Nitrogen is incorporated into the Sr3SiO5 host lattice through substituting SiO2 by Si3N4 in raw materials.
• The XRD results show the synthesized phosphor is isostructural with Sr3SiO5.
• The emission intensity and thermal stability are both enhanced with the increase of nitrogen content.

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 °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 (λemλem = 582 nm) and emission spectra (λexλex = 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.

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