High pressure evolution of YVO4:Pr3+ luminescence

Photoluminescence and time-resolved photoluminescence spectra of YVO4 doped with Pr3+ obtained at high hydrostatic pressure up to 76 kbar applied in a diamond anvil cell are presented. At pressures lower than 60 kbar the steady state emission spectra consist of sharp lines related to the D-1(2) -> H-3(4) transition in Pr3+. At pressures above 68 kbar the Pr3+ emission intensity decreases and the corresponding bands are replaced by a broad band peaking at 19 500 cm(-1) attributed to perturbed VO3-4 host luminescence. The quenching of the D-1(2) -> H-3(4) emission has been attributed to nonradiative transition to the charge transfer exciton trapped at Pr3+ ion. The recovering of the VO3-4 host luminescence at high pressure has been attributed to energy transfer from a Pr3+ trapped exciton (PTE) to the host YVO4. The kinetics of such a process is analyzed using the model of PTE considered as a Pr4+ + electron bound by the Coulomb potential at the delocalized Rydberg states.