Scintillation properties of Cs3Cu2I5:Tl crystals grown by Cz, EFG and Bridgman methods with a multifunctional melt growth furnace

Cs3Cu2I5:Tl is a novel scintillator boasting high density, a substantial light yield, and excellent energy resolution, making it promising for applications in gamma-ray spectroscopy. In this paper, we developed a multi-functional melt growth furnace capable of convenient configuration for the Czochralski (Cz), Edge-defined Film-fed (EFG), and Bridgman methods. We successfully grew Cs3Cu2I5:Tl crystals using the Cz, EFG, and Bridgman methods, yielding crystal sizes of 015 mm, 012 mm, and 030 mm, respectively. The obtained crystals exhibit satisfactory crystalline quality, although they are susceptible to cracks during the cooling, cutting, and polishing processes. Samples are taken from the crystals to undergo analysis to investigate their optical and scintillation properties. Findings indicate that our Cs3Cu2I5:Tl possess a large Stokes shift of 175 nm with nearly no spectral overlap between the PLE and PL spectra. The radioluminescence emission peaked at 505 nm, accompanied by a scintillation decay time of 828 ns. The samples exhibited a commendable energy resolution of 4.8% at 662 KeV and a high light yield of 83000 ph/MeV when coupled with a PMT. This study validates the viability of employing CZ and EFG methods for the growth of Cs3Cu2I5:Tl crystal, in addition to showcasing the Bridgman method for the growth of centimeter-scale Cs3Cu2I5:Tl crystals.