In situ preparation of a CsPbBr3/black phosphorus heterostructure with an optimized interface and photodetector application

Abstract

Zero-dimensional (0D)-2D nanostructures, which combine the efficient light-harvesting properties of 0D nanocrystals (NCs) and the ultrafast carrier transfer of 2D materials, have been widely used in optoelectronic devices. Although the most common way to fabricate 0D–2D nanostructures consists of a mixing process, the limited loading efficiency of NCs and the poor 0D–2D interface hinder the efficient photo-carrier generation and fast carrier separation/transfer in such systems. Herein, the in situ synthesis of CsPbBr₃/BP heterostructures via a hot-injection method was presented, revealing that both the formation process of CsPbBr₃ NCs and the CsPbBr₃/black phosphorous (BP) interfaces presented pronounced changes. This led to a larger CsPbBr₃ NC size, higher CsPbBr₃ NC loading efficiency, optimized combination of CsPbBr₃ and BP at the interface, and enhanced carrier transfer properties. In addition, the in situ synthesized CsPbBr₃/BP heterostructure was used as a photoactive material for the fabrication of photodetectors, which showed high detectivity (D*) of 2.6 × 10¹¹ Jones. This work highlights a novel strategy to optimize the 0D–2D heterostructure interface and to promote its carrier transfer efficiency, broadening the field of the applications of mixed-dimensional nanostructures.