The user has requested enhancement of the downloaded file.

Atomically thin molybdenum disulfide (MoS) is an ideal semiconductor material for field-effect transistors (FETs) with sub-10 nm channel lengths. The high effective mass and large bandgap of MoS minimize direct source-drain tunneling, while its atomically thin body maximizes the gate modulation efficiency in ultrashort-channel transistors. However, no experimental study to date has approached the sub-10 nm scale due to the multiple challenges related to nanofabrication at this length scale and the high contact resistance traditionally observed in MoS transistors. Here, using the semiconducting-to-metallic phase transition of MoS, we demonstrate sub-10 nm channel-length transistor fabrication by directed self-assembly patterning of mono- and trilayer MoS. This is done in a 7.5 nm half-pitch periodic chain of transistors where semiconducting (2H) MoS channel regions are seamlessly connected to metallic-phase (1T') MoS access and contact regions. The resulting 7.5 nm channel-length MoS FET has a low off-current of 10 pA/μm, an on/off current ratio of >10, and a subthreshold swing of 120 mV/dec. The experimental results presented in this work, combined with device transport modeling, reveal the remarkable potential of 2D MoS for future sub-10 nm technology nodes.

We report a change in the semimetallic nature of single-layer graphene after exposure to oxygen plasma. The resulting transition from semimetallic to semiconducting behavior appears to depend on the duration of the exposure to the plasma treatment. The observation is confirmed by electrical, photoluminescence and Raman spectroscopy measurements. We explain the opening of a bandgap in graphene in terms of functionalization of its pristine lattice with oxygen atoms. Ab initio calculations show more details about the interaction between carbon and oxygen atoms and the consequences on the optoelectronic properties, that is, on the extent of the bandgap opening upon increased functionalisation density.

b S Supporting Information T he two-dimensional character of graphene together with its unique electronic properties makes it a promising material for use in a wide range of electronic, 1 optoelectronic, 2,3 and biological applications. 4,5 In contrast with single-layer graphene (SLG), bilayer graphene (BLG) consists of two Bernal AB stacked SLG layers. BLG exhibits many of the properties featured by SLG such as semimetallicity and notable transport properties. Interestingly, unlike SLG, BLG can be rendered semiconducting by the application of a transverse electric field. 6À10 A bandgap can also be engineered in BLG by selective control of charge density. 11,12 Photoluminescence spectroscopy (PL) has been widely used to probe the optical transitions in modified graphene. 13À16 Pristine SLG shows no PL owing to its semimetallic character. However, modification of the lattice by functionalization with atomic and molecular species can render graphene semiconducting, and this phenomenon has been modeled and confirmed experimentally. 14 A few recent studies focused on the opening of