Two dimensional MoS2/graphene p-n heterojunction diode: Fabrication and electronic characteristics

Molybdenum disulfide (MoS2) films are currently the most potential semiconductor materials of the two-dimensional nano-material heterojunction. Few-layer MoS2 is an n-type semiconductor that has good mechanical strength, high carrier mobility, and has similar thickness as graphene. Graphene is presently the thinnest two-dimensional material with good thermal conductivity and high carrier mobility. The graphene Fermi level can be precisely controlled using the oxygen adsorption. Therefore, graphene can be tuned from zero-gap to p-type semiconductor material using the amount of adsorbed oxygen. In this study we combine few-layer MoS2 and graphene to produce a heterojunction and exhaustively study the interface properties for heterojunction diode application. According to the results, the MoS2 band-gap increases with decreasing thickness. The I-V characteristics of the MoS2/Graphene p-n junction diodes can be precisely tuned by adjusting different thicknesses of the MoS2 films. By applying our fabricating method, MoS2/Graphene heterojunction diode can be easily constructed and have potential to different applications.