| Two-dimensional?2D?layered materials have drawn a lot of attentions in recent researches,in which graphene has shown broad prospect in various of fields such as electronics and optoelectronics due to its excellent electrical properties.However,the zero-gap band structure of graphene seriously restricts its applications in electronic devices.Molybdenum disulfide?Mo S2?,due to its non-zero band gap and high optical absorptivity,has been regarded as a complementary material to graphene.Despite having lots of potential advantages,the ideal performances of layered Mo S2 FETs have not been realized so far due to the large resistance at its metal contact interfaces.In this paper,to solve this problem,the Mo S2-metal contact was improved by using graphene layers as electrodes of Mo S2 FETs,and the obtained structure has shown excellent performance in photoelectric measurements.The main focuses of this paper are listed as follows:The samples of graphene and Mo S2 were successfully prepared by mechanical exfoliation method,and comprehensively characterized by Optical Microscope,Atomic Force Measurement,Raman spectroscopy,Photoluminescence and so on.Using Ar+plasma to etch graphene and Mo S2,we not only found that etching time have multiple with the number of layers,but also could precisely control the etching thickness of graphene and Mo S2 by changing plasma etching time.Graphene/Mo S2 heterostructures were successfully prepared by deterministic transfer method.By selectively etching graphene in graphene-Mo S2 heterostructures,one can obtain graphene-contacted Mo S2 transistor successfully.The transistor shows an on-off ratio of about 106.The mobilities of the graphene-contacted Mo S2 transistor is about 42 cm2V-1s-1,which has been increased by 55%compared with the pristine Mo S2 FET with the same channel width.Using graphene with high carrier mobility as carrier transport layer and Mo S2 with outstanding light absorption as photosensitive layer,the photodetector of Mo S2 with graphene electrode was constructed,which greatly improved the photoelectric characteristics of Mo S2. |
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