Luminescence and spectroscopic properties of Sm2+ and Er3+ doped SrI2

Abstract The scintillation and luminescence properties of SrI 2 :1% Sm 2+ and SrI 2 :1% Er 3+ are reported. Single crystals were grown by the vertical Bridgman technique. Broad band Sm 2+ 5d–4f emission was observed centered at 750 nm with a radiative lifetime of 1.25 µs. The photoluminescence decay time increases with temperature due to self-absorption. With Er 3+ a clear charge transfer band was identified at 295 nm. The spectroscopic properties of Sm 2+ and Er 3+ are compared with those of Eu 2+ , Yb 2+ , Ce 3+ , and Nd 3+ doped in SrI 2 . The results are combined to construct a diagram with the vacuum referred electron binding energies for all divalent and trivalent lanthanide ions in SrI 2 which is fully consistent with the spectroscopic observations.