Near-infrared luminescence of chromium(V)-doped Li3PO4

The luminescence properties of Cr5+-doped Li3PO4 are reported and discussed. The luminescence of this ion in tetroxo coordination is reported. Broad-band luminescence in the near-infrared spectral region with a maximum at 9000 cm−1 is observed. Two origins which are separated by 19 cm−1 are observed in the luminescence spectrum due to the splitting of the 2E ground state by the combined action of the low-symmetry crystal field and the spin-orbit coupling. The luminescence decay time at 15 K is about 100 ns. The luminescence intensity decreases by 75% between 10 K and room temperature due to a non-radiative process.