Scintillation Properties of Perovskite Single Crystals

Low-cost solution-processed scintillation radiation detection materials are pursued urgently in ionization applications. Scintillators are key conversion materials that absorb high-energy X(γ) photons and convert them into UV-visible photons. Bulk mix organic-inorganic hybrid perovskites (CH₃NH₃PbCl_3-XBr_X) have been employed to detect X(γ) photons using a photon-photon conversion method. Optical properties were carefully investigated by photoluminescence (PL) spectra, PL lifetime, and X-ray excited luminescence (XEL) spectra at room temperature, which can be tuned with dopant Br concentration. Two XEL peaks centered at around 456 and 479 nm have been observed for the CH₃NH₃PbCl_2.85Br_0.15 single crystal scintillator. These two peaks originated from the near band-to-band emission and self-absorption-induced re-emission. Thick crystals are able to enhance the self-absorption induced re-emission, while suppressing the near band-to-band emission.