Perovskite CsPbBr3 single crystal detector for alpha-particle spectroscopy

Abstract

Here we report the first spectroscopic alpha particle detection based on CsPbBr3 detectors with asymmetric contacts. The CsPbBr3 single crystal was grown from the melt using Bridgman method and then fabricated into detectors with different contacts. The In/CsPbBr3/Au detector presented a low dark current density (∼100 nA/cm2) 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 the57Co 122 keV γ ray. The CsPbBr3 detector was capable of simultaneously resolving both the alpha particle (5.5 MeV) and γ ray (59.5 keV) peaks from 241Am radioactive isotope. The transport properties of CsPbBr3 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 cm2/(V ⋅ s) respectively. The calculated electron and hole mobility-lifetime products were 4.5 × 10−4 and 9.5 × 10−4 cm2/V, respectively, demonstrating superior transport properties of holes over electrons in CsPbBr3. 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.