Proceedings of Asia-Pacific Conference on Perovskite, Organic Photovoltaics&Optoelectronics (IPEROP25)
Publication date: 17th October 2024
CsPbBr3 single crystal X-ray and gamma-ray detectors match state-of-the-art performance with a few exceptions, particularly the detection speed is insufficient for photon counting medical imaging. The slow perovskite response is intrinsically limited by the low charge carrier mobility (µ), reported in CsPbBr3 to be 10-30 times smaller than that of CdTe. By using Time of Flight (ToF) technique with alternative voltage biasing (AC) mode CsPbBr3 crystals grown by the modified Bridgman method demonstrated two component hole mobility with median high mobility of 300 cm2V-1s-1 (while the best achieved - 520 cm2V-1s-1) and low mobility of 30 cm2V-1s-1. The fast component is quenched due to ionic migration and the reaction of the Bi electrode with Br- ions, while applying DC bias mode, commonly used in perovskite hard radiation detectors. Additionally, we examine the influence of temperature on charge carrier mobility. The reported mobility is the highest among lead-based perovskites and shows promise for applications with fast response requirements.
The work was financially supported by the Swiss Innovation Agency (Innosuisse) under grant agreement 46894.1 IP-ENG and by ETH Zürich through the ETH + Project SynMatLab: Laboratory for Multiscale Materials Synthesis.