Two-Dimensional Hybrid Halide Perovskite as Highly Efficient β-Ray Scintillator by Incorporation of Aromatic Cations

Scintillators are extensively employed in the fields of security inspection, industrial product analysis, and medical diagnosis, owing to their capability of converting high-energy ionizing radiation (e.g. α-, β-, γ-, X-, and neutron rays) into visible light. Specifically, organic scintillators – including single crystals, liquids, and plastics – are primarily utilized for detecting β-ray. However, organic single crystal scintillators, such as anthracene and naphthalene, encounter limitations associated with complexity in crystal growth and potential carcinogenicity resulting from the sublimation of substances. Liquid scintillators pose challenges in terms of manufacturing, transportation, storage, and handling due to their vulnerability to oxygen and flame. Meanwhile, plastic scintillators exhibit drawbacks owing to their low glass transition temperature of polymers and poor irradiation hardness.<br/>Consequently, organic-inorganic hybrid halide perovskites have emerged as a promising alternative scintillator for high light yield, tunable emission wavelength, and low-temperature solution processability. To enhance the scintillation efficiency of perovskites, comprehensive investigations on their structure and composition have been preceded. Specifically, two-dimensional (2D) perovskites are known to exhibit higher light yield and faster scintillation decay compared to three-dimensional (3D) perovskite owing to higher exciton binding energy. Moreover, long aliphatic molecules were introduced as organic cations of 2D perovskite to enhance the capturing efficiency of β-rays. Nevertheless, 2D perovskite incorporating aromatic molecules, which are known to facilitate the absorption and release of energy, has not yet been developed as a scintillator.<br/>Herein, we developed blue-emitting 2D hybrid halide perovskites and evaluated its scintillation properties under various types of radiation. More specifically, ammonium derivatives from organic scintillators (i.e. anthracene, naphthalene, or stilbene) were employed as cations, where aromatic rings effectively serve as centers for the absorption of radiation energy. The synthesized 2D perovskite exhibited a photoluminescence (PL) peak centered at 410 nm, along with a notably high PL quantum yield of 64.5%. Furthermore, it demonstrated highly efficient scintillation property under X-ray and β-ray (C-14, Ni-63). In this study, we proposed a new strategy to enhance scintillation efficiency by incorporating organic scintillator cations into 2D hybrid halide perovskites, thereby paving a way for applications in future nuclear radiation monitoring devices.