Subnanosecond time-resolved x-ray measurements using an organic-inorganic perovskite scintillator

We have developed a fast x-ray detector using an organic-inorganic perovskite scintillator of phenethylamine lead bromide $\left({\text{PhE-PbBr}}_4\right)$ . The scintillator had a dominant light emission with a fast decay time of 9.9 ns. An x-ray detector equipped with a 0.9-mm-thick ${\text{PhE-PbBr}}_4$ crystal was used to detect nuclear resonant scattering in ${}^{61}\text{N}\text{i}$ (the first excited level: 67.41 keV; lifetime: 7.6 ns) by using synchrotron radiation. With this detector, we could successfully record the decaying gamma rays emitted from ${}^{61}\text{N}\text{i}$ with a time resolution of 0.7 ns (full width at half maximum) and a relatively high detection efficiency of 24%.