High pressure and time resolved luminescence spectra of Gd3Ga5O12:Pr3+ crystal

Luminescence spectra and time resolved luminescence spectra of GGG crystal doped with Pr3+ were measured at high hydrostatic pressure from ambient to 220 kbar. Effect of pressure results in the red shift of all luminescence lines related to Pr3+ ion emission equals from −0.32 to −1.02 cm−1/kbar and in the diminishing of the luminescence lifetimes. The luminescence decay related to emission from 3P0 state was single-exponential and diminished with pressure from 23 μs at ambient pressure to 6.5 μs at 165 kbar. Luminescence decay related to transition form 1D2 state was two-exponential with longer decay equal to 162 μs at ambient pressure and 120 μs at 165 kbar. We discussed effect of pressure on the 1D2 → 3H4 luminescence and emission from 3P0 state in the context of non-radiative processes that depopulate the 3P0 and populate the 1D2 state, considering mainly multiphonon relaxation processes and depopulation via the praseodymium trapped exciton state.

Research highlights
► Luminescence and luminescence kinetic of the GGG:Pr3+ under pressure were presented.
► Below 120 kbar the non-radiative 3P0 → 1D2 relaxation takes place due to multiphonon relaxation.
► Above 120 kbar additional channel related intersystem crossing through the PTE becomes active.