Graphene　and　other　two-dimensional　(2D)　materials　have　emerged　as　promising　materials　for　future　optoelectric　applications.　However,　low　detectivity　of　two-dimensional　materials　based　photodetector　inhibits　their　application.　Here,　we　report　a　lateral　graphene/MoS2/graphene　(GMG)　heterostructure　photodetector　which　was　synthesized　by　chemical　vapor　disposition　(CVD).　Electrical　measurement　shows　that　on/off　ratio　is　up　to　10(6)　and　two　opposing　Schottky　junctions　are　connected　in　a　series.　Photocurrent　mapping　indicates　that　the　Schottky　junctions　formed　by　graphene　and　MoS2　are　the　core　part　of　the　device,　where　photoexcited　electron-hole　pairs　are　spontaneously　and　rapidly　separated.　The　responsivity　is　more　than　2　x　10(3)mA/W　and　the　maximum　specific　detectivity　is　as　high　as　10(13)　Jones,　respectively.　This　special　design　for　the　2D　materials　based　photodetector　with　high　detectivity　gives　great　potential　for　future　application　in　nano-optoelectronic　devices.　(C)　2018　Published　by　Elsevier　B.V.