Converting SrI ₂ :Eu ²⁺ into a near infrared scintillator by Sm ²⁺ co-doping

The luminescence and scintillation properties of SrI 2 single crystals doped with 5% Eu 2+ and 0.05%, 0.2% and 0.5% Sm 2+ are evaluated. X-ray excited and photoluminescence measurements show energy transfer from excited Eu 2+ ions to Sm 2+ ions. At a concentration of 0.5% Sm 2+ , the luminescence consists almost entirely of 740 nm emission from Sm 2+ 5d-4f transitions. Co-doping SrI 2 :5% Eu 2+ with Sm 2+ provides a novel method to bypass the self-absorption problem encountered in large SrI 2 :Eu 2+ crystals and, at the same time, provides a unique near-infrared emitting scintillator with a light yield of approximately 40,000 photons/MeV. Accepted Author ManuscriptRST/Fundamental Aspects of Materials and EnergyRST/Luminescence Material