(BZA)2PbBr4: A potential scintillator for photon-counting computed tomography detectors

Abstract

Due to recent development in detector technology, photon-counting computed tomography (PCCT) has become a rapidly emerging medical imaging technology. Current PCCT systems rely on the direct conversion of X-ray photons into charge pulses, using CdTe, CZT, or Si semiconductor detectors. Indirect detection using ultrafast scintillators coupled to silicon photomultipliers (SiPM) offers a potentially more straightforward and cost-effective alternative. In this work a new 2D perovskite scintillator, benzylamonium lead bromide (BZA)2PbBr4, is experimentally characterised as function of temperature. The material exhibits a 4.2 ns decay time under X-ray excitation at room temperature and a light yield of 3700 photons/MeV. The simulation tool developed by Van der Sar et al. was used to model the pulse trains produced by a SiPM-based (BZA)2PbBr4 detector. The fast decay time of (BZA)2PbBr4 results in outstanding count-rate performance as well as very low statistical fluctuations in the simulated pulses. These features of (BZA)2PbBr4, combined with its cost-effective synthesis make (BZA)2PbBr4 very promising for PCCT.