Detection of gamma photons using solution-grown single crystals of hybrid lead halide perovskites

The decay of the majority of radioactive isotopes involves the emission of gamma (gamma) photons with energies of similar to 50 keV to 10 MeV. Detectors of such hard radiation that are low-cost, highly sensitive and operate at ambient temperatures are desired for numerous applications in defence and medicine, as well as in research(1,2). We demonstrate that 0.3-1 cm solution-grown single crystals (SCs) of semiconducting hybrid lead halide perovskites (MAPbI(3), FAPbI(3) and I-treated MAPbBr(3), where MA = methylammonium and FA = formamidinium) can serve as solid-state gamma-detecting materials. This possibility arises from a high charge-carrier mobility-lifetime (mu tau) product of 1.0-1.8 x 10(-2) cm(2) V-1, a low dark carrier density of 10(9)-10(11) cm(-3) (refs 3,4), a low density of charge traps of 10(9)-10(10) cm(-3) (refs 3,5) and a high absorptivity of hard radiation by the lead and iodine atoms. We demonstrate the utility of perovskite detectors for testing the radiopurity of medical radiotracer compounds such as F-18-fallypride. Energy-resolved sensing at room temperature is presented using FAPbI(3) SCs and an Am-241 source.