Scintillation Properties of CsCu2I3 Perovskite Single Crystal Grown by Room Temperature Solution Processing Method

Abstract

Metal halide perovskites have received great interest in developing scintillator materials. Among various types of perovskites, low dimensional metal halide perovskites have high exciton binding energy and photo-luminescence quantum yield (PLQY), making them suitable for X-ray and $\gamma $ -ray detection. In this work, we report the growth and characterization (structural and optical) of 1-D CsCu₂I₃ single crystal (SC). The SC was grown using the solvent evaporation method at room temperature. The crystal exhibits an orthorhombic structure with Cmcm space group. The optical characterizations show a yellow photoluminescence (PL) with a large Stoke’s shift (~230 nm) that originate from self-trapped exciton (STE) emission. The X-ray photoelectron spectroscopy (XPS) results indicate that the addition of oleic acid (OA) prevents the oxidation of Cu⁺. Further, we coupled the SC with a silicon photomultiplier (SiPM) to study the scintillation properties. The grown crystal has been characterized for light output, energy resolution, linearity, and non-proportionality. The CsCu₂I₃ SC grown for this study exhibits a comparable light output of ~20000 ph/MeV to those grown using inverse temperature crystallization (ITC), as reported in the literature. However, the energy resolution reported in this study (11.57% at 662 keV) is better than the values reported for ITC-grown crystals in the literature. GEANT4 simulation toolkit has been used to perform the simulations, and the simulated intrinsic photopeak efficiencies for different volumes of CsCu₂I₃ scintillator have been obtained and compared with NaI:Tl and bismuth germanate (BGO) scintillators.