Near UV-pumped yellow-emitting Sr8MgSc(PO4)(7):Eu2+ phosphor for white-light LEDs with excellent color rendering index

Abstract

An Eu2+-activated Sr8MgSc(PO4)(7):Eu2+ yellow-emitting phosphor with strong luminescence was synthesized and its crystal structure has been refined and determined from the XRD profiles using synchrotron light source by Rietveld refinement method. Non-radiative transitions between Eu2+ ions in the Sr8MgSc(PO4)(7) host have also been demonstrated to be attributable to dipole-dipole interactions, and the critical distance was estimated to be 24.83 angstrom by using spectral overlap methods. In addition, white-light near-UV LEDs were fabricated by using a phosphor blend of composition-optimized yellow-emitting Sr8MgSc(PO4)(7):0.01Eu(2+) and blue-emitting BaMgAl10O17:Eu2+ commodity pumped with a 400 nm near-UV chip and the Ra value and reduced color temperature of were found to be 96.7 and 5,614 K, respectively. These results indicate that yellow-emitting Sr8MgSc(PO4)(7):xEu(2+) can serve as a promising candidate for application in white-light LEDs.