Bulk Organic-Inorganic Methylammonium Lead Halide Perovskite Single Crystals for Indirect Gamma Ray Detection

Scintillators that convert ionization radiation photons to UV-visible photons have attracted extraordinary attention. Traditional scintillators are associated with a vacuum photomultiplier tube that faces strict constraints of fragility, magnetic fields, and operated voltage, or coupled to a silicon photomultiplier (SiPM) with optical silicone grease. Here, we report a high-performance radiation detector with an indirect photon-to-photon conversion radiation detection model based on perovskite single crystals (SCs), where perovskite SCs have been directly integrated into the window of SiPM by using the solution growth method at low temperature. Tunable X (γ)-ray excited light emission in the range of 414 to 600 nm is obtained with different concentrations of Br doping, which greatly matches the response wavelength of SiPM. Small Br-doped CH₃NH₃PbBr_0.05Cl_2.95 SCs exhibit high transmittance and weak self-absorption, resulting in improved scintillation light emissions. Moreover, we have successfully collected a ¹³⁷Cs source gamma-ray pulse height spectrum with the SiPM readout. The MAPbBr_0.05Cl_2.95 scintillator exhibits a decay time of 0.14 ± 0.02 ns and a light yield of 18 000 photons/MeV with an energy resolution of 10.5 ± 0.4% at 662 keV. The results indicate that the CH₃NH₃PbBr_xCl_3-x perovskite SCs could enable the next generation of low-cost, fast, and fine-energy resolution scintillators.