Photoluminescence of Rare-Earth-Doped Ca4Ga2S7

The photoluminescence of Ca4Ga2S7crystals activated with Nd3+, Ce3+, Pr3+, and Tb3+was investigated between 77 and 300 K. The spectra of all the crystals studied show an emission band at 543 nm, which is due to the Nd3+G7/2→ I9/2transition. There is efficient nonradiative energy transfer from Ce3+, Pr3+, and Tb3+to Nd3+.