Photoluminescence properties and energy transfer of a single-phased white-emitting NaAlSiO4:Ce3+,Sm3+ phosphor

A series of tunable phosphors NaAlSiO4:Ce3+, Sm3+ were synthesized using a conventional high-temperature, solid-state method. Crystal structure, photoluminescence excitation, and emission spectra with fluorescence decay curves were investigated. Under UV excitation (325 nm), NaAlSiO4:Ce3+,Sm3+ showed strong blue emission located at 444 nm and orange-reddish emission centered at 563, 601, 648 and 712 nm, stemming from the characteristic emission for 4f-5d transition of Ce3+ and 4G(5/2)-> H-6(J) (J=5/2, 7/2, 9/2, 11/2) transition of Sm3+, respectively. In addition, we studied the detailed energy transfer process between Ce3+ and Sm3+ and found that it belonged to dipole-dipole resonance energy transfer. Furthermore, we noted that the white light emitting from the Ce3+, Sm3+ co-doped phosphors with the color coordinate (x=0.313, y=0.283) could be observed under 325 nm excitation, which was close to the ideal white light (x=0.33, y=0.33). The results indicated that this phosphor has a potential application as a single-phased alumino-silicate phosphor for ultraviolet white light-emitting diodes (UV-WLEDs).