Optical properties of (Y,Tb)PO_4 under VUV excitation

摘要

(Y,Tb)PO_4 were prepared by solid state reaction and their photoluminescence (PL) spectra were investigated under vacuum ultraviolet (VUV) excitation. The obtained results indicate that (Y,Tb)PO_4 can efficiently absorb the energy in the region of 112-243 nm and transfer it to the 5~D_4 energy level of Tb~(3+). After that, green light is emitted by Tb~(3+) due to the transitions from 5~D_4 energy level to the ground state. Under 147 nm excitation, the optimal emissive intensity is obtained when Tb~(3+) concentration is about 20%, which is about 110% of commercial phosphor Zn_(1.96)SiO_4:0.04Mn~(2+) with chromaticity coordinates of (0.354, 0.553) and the decay time of about 2.527 ms. According to the obtained experimental data, we tentatively explain the energy absorption, transfer and luminescent quenching for YPO_4:Tb~(3+) under 147 nm excitation.