High performance gamma-ray spectrometer based on Cs3Cu2I5 single crystal grown by room-temperature vacuum solvent-evaporation method

초록

"In this study, the properties of Cs3Cu2I5 (CCI) crystals grown using the Slow Vacuum Evaporation Technique (SVET) were examined. Crystals were grown at room temperature (300 K, 27 °C) under vacuum conditions, producing single crystals with maximum diameter of 13 mm over 23 days. We confirmed excellent crystallinity via X-ray diffraction (XRD), compositional uniformity via X-ray photoelectron spectroscopy (XPS), and homogeneity via electron probe micro analyzer (EPMA). UV-Vis measurements indicated a high transmittance of 83 % and a bandgap of 3.64 eV. The Stokes shift of 110 nm, smaller than previously reported values, contributed to faster decay times and improved low-energy detection feasibility. Time-resolved photoluminescence (TR-PL) showed a rapid decay component (4.1 ns), accounting for 95.11 % of the total decay, demonstrating superior properties compared to existing reports. The gamma-ray detection capabilities of the CCI crystals were evaluated using six radioactive sources (Am-241, Ba-133, Co-57, Na-22, Cs-137, and Mn-54), achieving excellent energy resolution, including 5.2 % at 662 keV. The crystals displayed a highly linear response to gamma radiation (R² = 0.99998) with a light yield of 55,613 photons/MeV. Moreover, assessments of multiple crystals grown under identical conditions showed consistent performance with a coefficient of variation (CV) of 1.23 %. These findings confirm that SVET is a highly effective and cost-efficient method for producing high-quality CCI crystals, offering significant advantages over other growth techniques. © 2025 Elsevier B.V.

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