1. Crystal structures of (a) single (AB²⁺X₃) and (b) double (A₂B⁺B³⁺X₆) halide perovskite^[5]

2. Optoelectronic properties of halide perovskites. (a) Photoluminescence spectra of mixed halide perovskites^[17]; (b) Trap densities and carrier mobilities of MAPbI₃ single crystals grown by solution method^[22]; (c) Extracted carrier lifetime of MAPbI₃ polycrystalline (MPC) film and single crystal (MSC) by EIS study^[23]; (d) Extracted carrier lifetime of MAPbI₃ single crystal (TPV decay curves) ^[23]; (e) Absorption coefficients versus photon energy of X/γ-ray^[30]; (f) Thickness dependent attenuation efficiencies to X-ray photons with energy of 50 keV^[30]

3. Schematic illustration of direct and indirect radiation detectors, as well as relaxation kinetics of X/γ-ray photons generated carriers in halide perovskite (①-④ represent the interaction process between rays and materials)

4. Development of halide perovskite based radiation detectors^{[19-21, 30, 32-34]}

5. (a) Time-resolved photocurrent of MAPbI₃ film based detector under 37 keV X-ray^[21]; (b) Photocurrent of MAPbBr₃ single crystal detector versus dose of 50 keV X-ray^[19]

6. Response characteristics of Cs₂AgBiBr₆ single crystal (2 mm thickness) based X-ray (30 keV) detector. (a) X-ray photocurrent and gain factor as a function of dose rate^[30]; (b) Temperature dependence of detector sensitivity with inset showing the photograph of single crystal device^[64]

7. X-ray images of (a) leaf and electronic chip^[21]; (b) A hand phantom^[33]; (c) An encapsulated metallic spring and a portion of a fish caudal fin^[81]; (d) Cs₂AgBiBr₆/PVA composite film based flexible X-ray detector^[30,82]

8. γ-ray spectroscopy of single crystal based organic-inorganic hybrid perovskite detector. (a) The bias dependence of the photocurrent generated by Cu Kα X-ray in a FAPbI₃ single crystal^[20]; (b) Energy spectroscopy curve of single crystal detector for ²⁴¹Am^[20]; (c) MAPbI₃ single crystal photo and the spectral response of ⁵⁷Co^[83]; (d) The spectral response of MAPcBr_2.94Cl_0.06 detector, CZT, NaI (Tl) detector to ¹³⁷Cs^[84]

9. (a) γ-ray energy spectrum of CsPbBr₃ single crystal grown by Bridgman method toward ¹³⁷Cs^[85]; (b) Linear response range of the detector^[85]; (c) Portable (FA/Cs)Pb(I/Br)₃ γ-ray spectrometer^[86] 1: single crystal probe, 2: preamplifier, 3: amplifier, 4: display, 5: ray source, 6: battery

10. CsPbX₃ quantum dot based halide perovskite scintillation detector^[87]. (a) Schematic representation of X-ray-induced luminescence; (b) Transmission electron microscopy image of the as-aynthesized CsPbBr₃ nanocrystals; (c) Tunable luminescence spectra of CsPbX₃ quantum dots under X-ray irradiation at 50 keV (dose rate of 278 μGy·s^-1); (d) Comparison of the optical sensitivity of various scintillator materials in response to exposure to X-rays produced at a voltage of 10 kV; (e) CIE chromaticity coordinates of the X-ray-induced visible emissions of 12 CsPbX₃ samples; (f) Multicolour X-ray scintillation from 3 types of perovskite nanocrystal scintillator; (g) CsPbBr₃-based scintillator as a function of dose rate; (h) Measured radioluminescence decay of the CsPbBr₃-based scintillator under excitation with a ¹³⁷Cs source

Table 1. Comparison of perovskite X/γ-ray detectors

Table 2. Halide γ-ray detector energy spectroscopy detection summary (ITC: Inverse temperature gradient crystallization)