Templated synthesis of CsPbBr3 nanowire arrays toward low dark current drift and stable X-ray detectors

Abstract

All-inorganic halide perovskite CsPbBr₃ with superior environmental stability, remarkable radiation hardness and great defect tolerance has emerged as a competitive material in radiation detection. However, the operational stability of CsPbBr₃ based detectors remains a problem due to their unstable electrical properties. Perovskite nanowires with a preferred orientation show greater accessibility compared with their single-crystal partners that undergo time-consuming growth. However, the synthesis of perovskite nanowire arrays with excellent stability, tunable distribution arrangements and adjustable compositions has been a major challenge. Herein, CsPbBr₃ perovskite columnar crystal films with a controlled diameter (50–400 nm) are successfully synthesized with porous anodic aluminum oxide (AAO) templates. The passivated surface between AAO and CsPbBr₃ nanowires resulted in reduced ion migration and stable operation performance. The CsPbBr₃ based X-ray detectors display a low dark current drift of 2.185 × 10⁻⁶ nA cm⁻¹ s⁻¹ V⁻¹, a high resistivity of 3.946 × 10¹¹ Ω cm and a detection limit of 3.70 μGy_air s⁻¹ with an AAO pore size of 50 nm. This work establishes a suitable method to synthesize all-inorganic perovskite nanowires with controlled diameters for stable X-ray detection performance.