Interfacial Charge Behavior Modulation in Perovskite Quantum Dot-Monolayer MoS2 0D-2D Mixed-Dimensional van der Waals Heterostructures

Fundamental understanding of charge behavior inside heterostructures is of vital importance for advancing high-performance optoelectronic applications. However, the charge behavior of 0D-2D mixed-dimensional van der Waals heterostructures (MvdWHs) in the photoexcited state remains elusive. In this work, an energy band alignment protocol is adopted to realize effective energy band structure engineering inside 0D-2D MvdWHs of perovskite quantum dots and MoS2 monolayer with precisely designed typical type I and type II heterostructures, respectively. A profile and in-depth understanding of interfacial photoinduced charge behavior is determined from two opposite perspectives based on MvdWHs. Sufficient comparison of a series of optical characterization results, including Raman shift, quenched photoluminescence, visualized suppressed fluorescence intensity, and shortened fluorescence lifetime imaging, clearly verifies that interfacial charge behavior can be tailored by varying the band alignment in 0D-2D MvdWHs. Furthermore, the photoresponse performance and the relatively stronger and weaker photogating effects of such MvdWH-based phototransistors also demonstrate modulation of interfacial charge behavior in 0D-2D MvdWHs via energy band structure engineering, which is still feasible for optoelectronic performance optimization. These results are expected to shed light on designing novel functional devices and advancing the development process of 0D-2D MvdWHs in the foreseeable future.