Segregation of Tl ions in Bridgman-grown Cs3Cu2I5:Tl single crystal scintillators.

Single crystals of Cs 3 Cu 2 I 5 :Tl have gained great attention due to superior scintillation performance. However, the effect of segregation behavior of Tl dopant on scintillation performance of Cs 3 Cu 2 I 5 :Tl single crystals is still unclear. In this work, single crystals of Cs 3 Cu 2 I 5 doped with different Tl concentrations with a diameter of 7 mm and a length of 90 mm were grown by the Bridgman method. The effective segregation coefficient of Tl ions in the Cs 3 Cu 2 I 5 single crystal was determined as 0.2 ± 0.03. The effects of Tl segregation on scintillation properties, such as light yield, energy resolution, and scintillation decay time, were systematically studied. It is found that with the increase of Tl concentration, the energy resolution remains relatively stable, ranging from 3.8 % to 4.4 % at 662 keV, while the light yield increases from 65,000 photons/MeV to 90,000 photons/MeV. [ABSTRACT FROM AUTHOR]