A study on photoluminescence and energy transfer of SrAlSi4N7:Eu2+, Ce3+ phosphors for application in white-light LED

Abstract A series of Ce 3+ - and Eu 2+ -coactivated SrAlSi 4 N 7 phosphors have been synthesized by the solid-state reaction method and their luminescence properties have been investigated as a function of activator and co-activator concentrations for the first time. The energy transfer from Ce 3+ to Eu 2+ has been verified by directly observing the significant spectra overlap and the systematic relative intensity variation of emission bands of Ce 3+ and Eu 2+ . The energy transfer from Ce 3+ to Eu 2+ has been demonstrated to be a resonant type, via dipole–dipole mechanism. The critical distance of Ce 3+ and Eu 2+ has also been calculated. The emitting color of phosphors can be tuned from yellow to red with increasing Eu 2+ /Ce 3+ ratio. These results indicate SrAlSi 4 N 7 :Eu 2+ , Ce 3+ phosphor with appropriate tuning of activator and co-activator content might be promising as an UV or blue-convertible color-tunable phosphor for white LEDs.