Luminescence Enhancement and Enlarged Dirac Point Shift of MoS2/Graphene Hetero-Structure Photodetectors With Postgrowth Annealing Treatment

Enhanced photoluminescence intensities are observed for the MoS
₂
film prepared by chemical vapor deposition (CVD) with an additional 850°C postgrowth annealing procedure under sulfur-rich environment. The enlarged Dirac point shift of the MoS
₂
/graphene hetero-structure photodetectors with the postgrowth annealing procedure suggests that more photoexcited electrons will transport to the graphene and effectively higher n-type doped the channel. The direct 2-D crystal hetero-structure growth by using CVD has avoided the complicated procedure of sequential attachment of different 2-D crystals, which is advantageous for the practical application of 2-D crystal heterostructures.