A novel yellow phosphor for white light emitting diodes

This paper reports that a novel yellow phosphor, LiSrBO₃:Eu²⁺, was synthesized by the solid-state reaction. The excitation and emission spectra indicate that this phosphor can be effectively excited by ultraviolet (360 and 400 nm) and blue (425 and 460 nm) light, and exhibits a satisfactory yellow performance (565 nm). The role of concentration of Eu²⁺ on the emission intensity in LiSrBO₃ is studied, and it is found that the critical concentration is 3 mol%, and the concentration self-quenching mechanism is the dipole--dipole interaction according to the Dexter theory. White light emitting diodes were generated by using an InGaN chip (460 nm or 400 nm) with LiSrBO₃:Eu²⁺ phosphor, the CIE chromaticity is (x = 0.341, y = 0.321) and (x = 0.324, y = 0.318), respectively. Therefore, LiSrBO₃:Eu²⁺ is a promising yellow phosphor for white light emitting diodes.