Perovskite CsPbBr ₃ single crystal detector for alpha-particle spectroscopy

Here we report the first spectroscopic alpha particle detection based on CsPbBr ₃ detectors with asymmetric contacts. The CsPbBr ₃ single crystal was grown from the melt using Bridgman method and then fabricated into detectors with different contacts. The In/CsPbBr ₃ /Au detector presented a low dark current density (∼100 nA/cm ² ) and temporal stable performance under high electric field (1000 V/cm). Such detector demonstrated excellent gamma ray resolving capability with a full-width at half maximum (FWHM) of ∼5.9 keV for the ⁵⁷ Co 122 keV γ ray. The CsPbBr ₃ detector was capable of simultaneously resolving both the alpha particle (5.5 MeV) and γ ray (59.5 keV) peaks from ²⁴¹ Am radioactive isotope. The transport properties of CsPbBr ₃ were then determined based on the alpha particle spectra and corresponding rise time distributions. The equivalent values of electron and hole mobilities were indicated as 63 and 49 cm ² /(V ⋅ s) respectively. The calculated electron and hole mobility-lifetime products were 4.5 × 10 ⁻⁴ and 9.5 × 10 ⁻⁴ cm ² /V, respectively, demonstrating superior transport properties of holes over electrons in CsPbBr ₃ . This work widens the scope of perovskite detectors to encompass charged radiation as well as high energy X/γ rays, and will significantly promote and guide further studies on perovskite materials for radiation detection applications.