Cesium lead bromide semiconductor radiation detectors: crystal growth, detector performance and polarization

Abstract

Cesium lead bromide (CsPbBr₃) is an upcoming semiconductor radiation detector that has the potential to match the detection properties of cadmium zinc telluride (CZT) and thallium bromide (TlBr). In this paper, we report on CsPbBr₃ gamma detectors with an uncorrected energy resolution of 2% at 662 keV with photopeak-to-Compton ratios as high as 14.3 and hole mobility-lifetime products (μτ_h) as high as 1.7 × 10⁻² cm² V⁻¹. Furthermore, we demonstrate that the processes employed for material purification and crystal growth of high-performing devices are scalable, and large (up to 65 mm in diameter) ultrahigh purity CsPbBr₃ crystals have been successfully grown. Using optimized growth conditions and detector fabrication processes, we were able to mitigate the polarization problem where it was revealed that the polarization process is highly dependent on the crystal quality and the electric field direction with respect to the orientation of the crystal.