Influence of Dual-Organic Cation and Inorganic Ion Doping on the Properties of Perovskite Scintillators

Hybrid organic-inorganic perovskite (HOIP) single crystals have captured significant attention due to their remarkable luminescent features, excellent photo-absorption capabilities, high exciton binding energy, and environmental stability. Current research focuses on halide perovskites incorporating phenethylammonium (PEA), butylammonium (BA), benzylammonium (BZA), and methylammonium (MA), generating considerable interest in the scientific community. Despite notable advantages such as high light yields (LYs) (>10 photons/keV) and faster photoluminescence (PL) decay time (<3 ns), challenges such as the fast component of decay, high mass density, and efficiency of electron-hole transfer persist, limiting their suitability for timing applications. Thus, enhancing structural, optical, and scintillation properties requires a comprehensive exploration of crystal growth optimization through the incorporation of dual-organic cations and inorganic ion doping. This review emphasizes the impact of structural variations on the optical and scintillating properties of HOIP crystals using a low-temperature solution process. Our review discusses investigation techniques, including X-ray diffraction, PL, time-resolved PL, radioluminescence, thermoluminescence, pulse height spectra (PHS), and scintillation time profiles. Our review begins by introducing dual-aliphatic organic cations in 2-D HOIP, which demonstrate promising improvements in LYs and energy resolution. Subsequently, we expand our review to include dual-aromatic organic cations, which contribute to enhancing scintillation decay time and electron-hole charge transfer efficiency. Then, our approach integrates the incorporation of 3-D HOIP into 2-D HOIP structures, resulting in new perovskite crystal structures with a higher mass density over 3.0 g/cm3, the fastest PL decay time of <1 ns, and a fast component of scintillation decay of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\ll 9$ </tex-math></inline-formula> ns. Finally, we briefly expand our review to include inorganic ion doping, which tunes the bandgap and enhances the LYs. This review emphasizes the significant role of dual-organic cations and inorganic ion doping in advancing scintillating materials, paving the way for applications such as positron emission and photon-counting computed tomography (PCCT).