Improvement and restoration of spectral performance of CsPbBr3 gamma radiation detectors

AbstraktAbstract

The sensitivity of perovskite crystals to moisture, thermal degradation, ion migration and other factors can cause performance degradation and instabilities on relatively short time scales. In this paper we examined a number of procedures, which we call stabilization, to mitigate and stabilize these effects in CsPbBr3 X-ray and gamma-ray detectors. It is shown that the spectrometric performance can be improved by applying a reverse bias voltage to the crystal with a simultaneous thermal stimulation at +50 °C. In fact, the energy resolution of six single crystal test detectors improved across the entire energy range by an average of 2 keV at 59.5 keV (241Am), 3 keV at 122 keV (57Co) and 14 keV at 662 keV (137Cs). Furthermore, as detector performances monitored from complete degradation to a return to spectroscopic level, the detector noise level decreased by a factor of 15. The leakage currents of the detectors before and after the stabilization proceedure was applied remained virtually unchanged, indicating that reversing the electric field strength has only a minor effect on the Schottky barrier. The physical mechanisms of degradation and recovery of properties in CsPbBr3 crystals are analyzed. Spectra are presented

The sensitivity of perovskite crystals to moisture, thermal degradation, ion migration and other factors can cause performance degradation and instabilities on relatively short time scales. In this paper we examined a number of procedures, which we call stabilization, to mitigate and stabilize these effects in CsPbBr3 X-ray and gamma-ray detectors. It is shown that the spectrometric performance can be improved by applying a reverse bias voltage to the crystal with a simultaneous thermal stimulation at +50 °C. In fact, the energy resolution of six single crystal test detectors improved across the entire energy range by an average of 2 keV at 59.5 keV (241Am), 3 keV at 122 keV (57Co) and 14 keV at 662 keV (137Cs). Furthermore, as detector performances monitored from complete degradation to a return to spectroscopic level, the detector noise level decreased by a factor of 15. The leakage currents of the detectors before and after the stabilization proceedure was applied remained virtually unchanged, indicating that reversing the electric field strength has only a minor effect on the Schottky barrier. The physical mechanisms of degradation and recovery of properties in CsPbBr3 crystals are analyzed. Spectra are presented