Enhanced sensitivity in self-powered Dion–Jacobson perovskite X-ray detectors via a ternary-solvent-ink approach

Abstract

2D Dion–Jacobson (DJ) perovskites have attracted increasing attention in X-ray detection due to their improved charge transport properties relative to the common Ruddlesden–Popper (RP) counterparts, while maintaining commendable environmental stability. However, achieving scalable and high-throughput manufacturing of the high-performance DJ perovskite X-ray detectors presents a notable challenge. Here, we have employed a ternary-solvent-ink strategy to fabricate quasi-2D DJ perovskite films for X-ray detectors via a spray-coating process. Our results indicate that the incorporation of ionic liquid methylammonium acetate into the conventional binary solvent precursor, composed of N,N-dimethylformamide and dimethyl sulfoxide, effectively impedes the formation of small n phases and concurrently suppresses the pinholes in the resulting DJ perovskite films, thus facilitating improved charge transport properties. Consequently, a high sensitivity of 4853 μC Gy_air⁻¹ cm⁻² and an ultralow detection limit down to 39 nGy_air s⁻¹ have been achieved in the devices under the self-powered mode, representing the best performing DJ perovskite film based X-ray detectors that operate without external bias. The results presented here signify a crucial advancement towards the scalable production of quasi-2D DJ perovskite X-ray detectors for high-performance X-ray detection applications in the future.