Luminescence concentration quenching of 1D2 state in YPO4:Pr3+

Under selective excitation of the 3P0 level of the Pr3+ ion in YPO4, the emission spectra and fluorescence decay curves were measured at different concentrations and temperatures. The origin of the spectral line located at 16 318 cm-1 (612.8 nm) was discussed and attributed to the 1D2→ 3H4 transition. The process of concentration quenching for the 1D2 state was also studied. Using the Inokuti-Hirayama model, the non-exponential fluorescence decay curves of the 1D2 level were fitted. The result shows that dipole-quadrupole interaction between Pr3+ ions, which causes 1D2→ 1G4 and 3H4→ 3F4 cross-relaxation, results in the quenching of 1D2 emissions.