High-Quality Core-Shell Structure Perovskite Nanowires via Liquid-Phase Coating Growth and Their Optoelectronic Properties

• 1、School of Integrated Circuits,Dalian University of Technology,Dalian 116600

Abstract：Metal halide perovskite materials have emerged as a rapidly growing research field, and have shown great research value in the fields of optics and optoelectronics due to their unique geometric structures and optical characteristics. However, perovskite nanowires with core-shell heterostructures have rarely been reported. In this work, CsPbI3/(PEA)2PbI4 core-shell heterostructured nanowires were synthesized via an antisolvent-assisted recrystallization method, leveraging the intrinsic self-assembly characteristics of perovskite crystals. The δ-CsPbI3 single-crystal nanowires were uniformly encapsulated by a (PEA)2PbI4 shell layer. Importantly, by optimizing preparation parameters such as the liquid-phase shell growth duration and the volume or concentration of the (PEA)?PbI? precursor solution droplets, the quality of the core-shell nanowires could be precisely controlled. Furthermore, photodetectors based on individual CsPbI3/(PEA)2PbI4 core-shell nanowires were fabricated to investigate their optoelectronic performance systematically. Electrical measurements revealed that under a bias of 5 V and 405 nm ultraviolet illumination, the devices exhibited an on/off ratio of approximately 1.8×102, a maximum responsivity of about 52 mA W-1, and an outstanding detectivity up to 1.76×1013 Jones. This study not only provides a robust synthetic approach for core-shell structured perovskite nanowires but also highlights their promising potential in advanced optoelectronic device applications.

Keywords： Halide perovskite Nanowires Core-shell structure (PEA)2PbI4 CsPbI3 Photodetector