Crystal growth and scintillation properties of Pr-doped SrI₂ single crystals

Pr-doped SrI₂ (Pr:SrI₂) single crystals with various Pr concentrations were grown by the halide-micro-pulling-down (H-μ-PD) method, and the scintillation properties were investigated. Pr1%:SrI₂ single crystal with high transparency could be grown by the H-μ-PD method while Pr2, 3 and 5%:SrI₂ single crystals included some cracks and opaque parts. In the photoluminescence spectrum of the Pr1%:SrI₂ single crystal, an emission peak originated from the Pr³⁺ ion was observed around 435 nm while the radioluminescence spectra showed an emission peak around 535 nm for the undoped SrI₂ and Pr:SrI₂ single crystals. Light yields of Pr1, 2, 3 and 5%:SrI₂ single crystals under γ-ray irradiation were 7700, 8700, 7200 and 6700 photons/MeV, respectively. Decay times of Pr1 and 2%:SrI₂ single crystals under γ-ray irradiation were 55.9 and 35.0 ns of the fast decay component, and 435 and 408 ns of the slow decay component, respectively.