Potential tunable white-emitting phosphor LiSr 4(BO 3) 3:Ce 3+, Eu 2+ for ultraviolet light-emitting diodes

Abstract

A novel Ce 3+/Eu 2+ co-activated LiSr 4(BO 3) 3 phosphor has been synthesized by traditional solid-state reaction. The samples could display varied color emission from blue towards white and ultimately to yellow under the excitation of ultraviolet (UV) light with the appropriate adjustment of the relative proportion of Ce 3+/Eu 2+. The resonance-type energy transfer mechanism from Ce 3+ to Eu 2+ in LiSr 4(BO 3) 3:Ce 3+, Eu 2+ phosphors is dominant by electric dipole–dipole interaction, and the critical distance is calculated to be about 29.14 Å by the spectra overlap method. White light was observed from LiSr 4(BO 3) 3:mCe 3+, nEu 2+ phosphors with chromaticity coordinates (0.34, 0.30) upon 350 nm excitation. The LiSr 4(BO 3) 3:Ce 3+, Eu 2+ phosphor has potential applications as an UV radiation-converting phosphor for white light-emitting diodes.