Characterization of the VUV excitation spectrum of BaZr(BO3)2:Eu

The excitation spectra of M (M=Si4+, Ti4+) and Eu3+ co-doped BaZr(BO3)2, BaZrO3:Eu and La2Zr2O7:Eu in the vacuum ultraviolet (VUV) regions of 110-300 nm are investigated and the host-lattice absorption are characterized. The result indicated that BaZr(BO3)2:Eu3+ phosphor has a strong absorption under the VUV excitation, and in the host-lattice excitation, the strong band at 130-160 nm could be due to the BO3 atomic groups; the band at 160-180 nm is related to the excitation of Ba-O; 180-200 nm corresponds to the charge transfer (CT) transition of Zr-O. The band at 200-235 nm due to the CT band of Eu3+-O2− and a bond valence study explained the observed weak CT band of Eu3+-O2− in the excitation spectra of BaZr(BO3)2:Eu3+. The emission results show that Si4+ can sensitize luminescence in the host of BaZr(BO3)2:Eu but Ti4+ has no improvement effect on luminescence.