Electronic properties and rare-earth ions photoluminescence behaviors in borosilicate: SrB2Si2O8

Undoped and RE ions doped SrB2Si2O8 were successfully synthesized. After the application of UV and VUV spectroscopy measurements, we made a novel discovery that the emission of SrB2Si2O8:Eu prepared in air can be switched between red and blue by the different excitations. The information is that quite a part of Eu3+ was spontaneously reduced to Eu2+ in air. The PL properties of Eu2+ in VUV and Eu3+, Ce3+ and Tb3+ in UV–VUV region in SrB2Si2O8 were evaluated for the first time. The excitation mechanisms of the O2−–Eu3+ CT, Ce3+f–d and Tb3+f–d transitions in UV region as well as the Eu3+f–d, O2−–Ce3+ CT, O2−–Tb3+ CT transitions and the host lattice absorption in VUV region were established. In addition, first principles calculation within the LDA of the DFT was applied to calculate the electronic structure and linear optical properties of SrB2Si2O8 and the results were compared with the experimental data.

Graphical abstractThe emissions of SrB2Si2O8:Eu prepared in air can be switched between the red (611 nm) and the blue (440 nm) by different excitations: under 254 nm excitation the Eu3+ red emission is dominant while under 365 nm excitation the Eu2+ blue emission presides at the emission spectra; when excited by 340 nm it emits almost the pure blue; and when excited by 395 nm the two emissions present nearly equivalent intensity.Figure optionsDownload full-size imageDownload as PowerPoint slide