Self‐reduction process and enhanced blue emission in SrAl 2 Si 2 O 8 : Eu, Tb via electron transfer from Tb 3+ to Eu 3+

Eu, Tb co‐doped SrAl 2 Si 2 O 8 luminescent materials were synthesized via a high‐temperature solid‐state reaction. Excitation spectra of SrAl 2 Si 2 O 8 : Eu 2+ gives two broad excitation bands maximizing at 270 and 330 nm, resulting from splitting Eu 2+ energy levels in octahedral crystal field. Eu single doped SrAl 2 Si 2 O 8 luminescent material exhibits two emission bands at about 406 and 616 nm. Intensity of the blue emission from Eu 2+ is always strong, compared with that of the red emission band of Eu 3+ . Reduction from Eu 3+ to Eu 2+ can be explained with the model of charge compensation. Blue emission in SrAl 2 Si 2 O 8 : x Eu was strengthened after incorporation of Tb, which can be explained by electron transfer from Tb 3+ to Eu 3+( T b 3 + + E u 3 + → T b 4 + + E u 2 + ) . Under 230 nm excitation, intensity of Tb 3+ emission was nearly unchanged and that of Eu 2+ was increased, obviously due to the delivery of more electrons to Eu 3+ . The strongest emission of Eu 2+ in 0.09Eu/0.06Tb co‐doped SrAl 2 Si 2 O 8 and excited at 270 and 330 nm was remarkably enhanced by about four times compared to that of 0.15Eu Single doped SrAl 2 Si 2 O 8 . All of the results indicate that SrAl 2 Si 2 O 8 : x Eu, y Tb are potential blue emitting luminescent materials for UV‐LEDs. More importantly, this research may provide a new perspective in designing broad band blue luminescent materials.