MoS_2 transistors fabricated via plasma-assisted nanoprinting of few-layer MoS_2 flakes into large-area arrays

摘要

Large-area few-layer-MoS_2 device arrays are desirable for scale-up applications in nanoelectronics. Here we present a novel approach for producing orderly arranged, pristine few-layer MoS_2 flakes, which holds significant potential to be developed into a nanomanufacturing technology that can be scaled up. We pattern bulk MoS_2 stamps using lithographic techniques and subsequently transfer-print prepatterned MoS_2 features onto pristine and plasma-charged SiO_2 substrates. Our work successfully demonstrates the transfer printing of MoS_2 flakes into ordered arrays over cm~2-scale areas. Especially, the MoS_2 patterns printed on plasma-charged substrates feature a regular edge profile and a narrow distribution of MoS_2 flake thicknesses (i.e., 3.0 ± 1.9 nm) over cm~2-scale areas. Furthermore, we experimentally show that our plasma-assisted printing process can be generally used for producing other emerging atomically layered nanostructures (e.g., graphene nanoribbons). We also demonstrate working n-type transistors made from printed MoS_2 flakes that exhibit excellent properties (e.g., ON/OFF current ratio 10 ~5-10~7, field-effect mobility on SiO_2 gate dielectrics 6 to 44 cm~2/(V s)) as well as good uniformity of such transistor parameters over a large area. Finally, with additional plasma treatment processes, we also show the feasibility of creation of p-type transistors as well as pn junctions in MoS_2 flakes. This work lays an important foundation for future scale-up nanoelectronic applications of few-layer-MoS_2 micro- and nanostructures.