Direct CVD growth of MoS₂ on chemically and thermally reduced graphene oxide nanosheets for improved photoresponse

The direct chemical vapor deposition (CVD) of transition metal dichalcogenides (TMDCs) on graphene or oxide (GO) allows for the scalable production van der Waals heterostructures (vdWHs). Herein, considering that CVD growth TMDCs depends largely surface property substrate, we compared chemically reduced GO (CrGO) and thermally (TrGO) as substrates to induce MoS2 without a seeding promoter. On monolayer (1L) three-layer CrGO TrGO nanosheets, more triangular flakes were found than TrGO. This is because with less defects could promote TrGO, which normally carries defects. Such difference was not obvious when thickness nanosheets exceeded five layer. As demonstration, obtained MoS2@1L-CrGO MoS2@1L-TrGO vdWH showed much higher photosensitivities 1L under both blue red laser irradiation. In particular, density larger photosensitivity MoS2@1L-TrGO. addition, rolling up into MoS2@CrGO MoS2@TrGO nanoscrolls further enhanced their photosensitivities, due presence multiple interfaces in scrolled structure. Our work demonstrates reduction modified promotes form vdWHs related scroll structures, are promising optoelectronics flexible electronics.