Free-Standing Multilayer MoS2-BP Heterostructures for High Performance Self-Powered Photodetector

Abstract

Phototransistors based on two-dimensional materials such as graphene, transition metal sulfides, and black phosphorus are widely used in in recent years. However, these materials have weak optical absorption, low carrier mobility or poor air stability, which restrict their application in the field of high-sensitivity detection. The inter-stacking of two-dimensional semiconductors can achieve excellent performance, and has promising applications in the field of optoelectronics. The stacking of two-dimensional semiconductors can form van der Waals heterostructures with low defect states and spatial homogeneity, which is an effective way to improve the performance of 2D photodetectors. Based on this, this paper constructs a free-standing multilayer MoS2-BP heterostructure by mechanical exfoliation for high performance self-powered photodetector. The strong space charge region can effectively separate the photogenerated carriers, so it has a good photodetection capability in the self-driven state. Moreover, we analyse and summarize the working mechanism of photodetectors based on 2D materials, and review high sensitivity detectors of recent years based on 2D material heterojunction. Finally, the challenges to further improve the detection sensitivity are pointed out. Thus, our free-standing multilayer MoS2-BP heterostructure propose a useful experience and reference for the future development of self-power photodetectors.