Cs4 EuI6∶Sm近红外闪烁晶体的生长及发光性能研究OA北大核心CSTPCD

With the rapid development of silicon-based light detectors with high detection efficiency and long-wavelength sensitivity,the development of near-infrared scintillation crystals has become a hotspot.Especially,the Sm2+doped europium-based halide crystals exhibit excellent near-infrared luminescence properties.In this paper,Cs4 EuI6∶Sm near-infrared scintillation crystals with a size of cm-level were successfully prepared by Bridgman method.The composition and structure were discussed by XRD,XPS and ICP-OES methods,indicating that the Sm2+was introduced and has no obvious effect on the crystal structure of the matrix.Under ultraviolet and X-ray excitation,the crystal has two luminescence centers(Eu2+and Sm2+),and the emission peaks are located at 450 and 840 nm,respectively,corresponding to the 5d→4f luminescence of Eu2+and Sm2+.The decay time of Eu2+and Sm2+is at the level of microsecond under ultraviolet excitation.The results show that the emission wavelength gradually varies from blue to near infrared as Sm2+doping concentration increased.The effects of Sm2+concentration on the luminescence properties,Eu2+-Sm2+energy transfer and decay time of the crystals were also studied,which means that the luminescence properties can be tuned by adjusting the Sm2+doping concenstration.