Li L Xie, Mengzhou M Liao, Shuopei S Wang, Hua H Yu, Luojun L Du, Jian J Tang, Jing J Zhao, Jing J Zhang, Peng P Chen, Xiaobo X Lu, Guole G Wang, Guibai G Xie, Rong R Yang, Dongxia D Shi, Guangyu G Zhang
2D semiconductors are promising channel materials for field-effect transistors (FETs) with potentially strong immunity to short-channel effects (SCEs). In this paper, a grain boundary widening technique is developed to fabricate graphene electrodes for contacting monolayer MoS2 . FETs with channel lengths scaling down to ≈4 nm can be realized reliably. These graphene-contacted ultrashort channel MoS2 FETs exhibit superior performances including the nearly Ohmic contacts and excellent immunity to SCEs. This work provides a facile route toward the fabrication of various 2D material-based devices for ultrascaled electronics.