Investigation of the luminescence properties of Tb3+-doped Li6Y(BO3)3 phosphors in VUV–VIS range

The electronic structure of Li6Y(BO3)3 is studied theoretically by using the density functional theory, and the photoluminescent properties of a series of Li6Y(BO3)3:Tb3+ phosphors excitable by vacuum ultraviolet (VUV) and UV-light are reported. The calculated result shows that Li6Y(BO3)3 is an indirect band gap material, the top of VB is dominated by O 2p orbital, and the bottom of CB is mainly contributed to Y 4d orbital. For the excitation spectrum, the host-related absorption band, f–f and f–d transitions of Tb3+, and charge transfer of O2−→Tb3+ in Li6Y(BO3)3:Tb3+ are assigned. Among them, the host-related absorption band is determined to be around 183 nm from the spectrum analysis and a comparison with the result of electronic structure calculations is made. Under both 377 nm and 147 nm light excitation, Li6Y(BO3)3:Tb3+ phosphors show green-emitting color due to the prominent 5D4–7F5 transition of Tb3+.