Large-area flexible photodetector based on atomically thin MoS2/graphene film

Abstract

In this paper, we demonstrate a large-area flexible photodetector based on vertically stacked atomically thin MoS2/graphene film. The MoS2 film is grown by CVD method. We have realized the growth of several square millimeter continuous monolayer MoS2 film via precisely control the atmosphere and temperature in the tube furnace. In experiment, the MoS2 and graphene film was transferred on PET substrate successively. Polymer electrolyte composed of PEO and LiClO4 was introduced to fabricate the side-gated flexible photodetector. The devices exhibit high performance at low operation voltage. External responsivity is about 3.5 A/W at Vgs = −1 V, Vds = 1 V with incident power of 60 μW (520 nm). Noteworthy is that the transmittance of the heterostructure at 520 nm is only about 10.5%, the internal responsivity even reaches to about 33.3 A/W, which is higher than most of the flexible photodetectors based on nanomaterials. Besides, the devices display high stability during transient on/off test. We believe the MoS2/graphene photodetector would be a promising candidate in flexible electronic system. Besides, such hybrid film design is also portable and meaningful for future photodetector investigation.