Nanoimprint-Assisted Shear Exfoliation (NASE) for Producing Multilayer MoS2 Structures as Field-Effect Transistor Channel Arrays.

MoS2 and other semiconducting transition metal dichalcogenides (TMDCs) are of great interest due to their excellent physical properties and versatile chemistry. Although many recent research efforts have been directed to explore attractive properties associated with MoS2 monolayers, multilayer/few-layer MoS2 structures are indeed demanded by many practical scale-up device applications, because multilayer structures can provide sizable electronic/photonic state densities for driving upscalable electrical/optical signals. Currently there is a lack of processes capable of producing ordered, pristine multilayer structures of MoS2 (or other relevant TMDCs) with manufacturing-grade uniformity of thicknesses and electronic/photonic properties.

Multiple MoS2 Transistors for Sensing Molecule Interaction Kinetics.

Atomically layered transition metal dichalcogenides (TMDCs) exhibit a significant potential to enable next-generation low-cost transistor biosensors that permit single-molecule-level quantification of biomolecules. To realize such potential biosensing capability, device-oriented research is needed for calibrating the sensor responses to enable the quantification of the affinities/kinetics of biomolecule interactions. In this work, we demonstrated MoS2-based transistor biosensors capable of detecting tumor necrosis factor--alpha (TNF-α) with a detection limit as low as 60 fM.

Enhancement of photovoltaic response in multilayer MoS2 induced by plasma doping.

Layered transition-metal dichalcogenides hold promise for making ultrathin-film photovoltaic devices with a combination of excellent photovoltaic performance, superior flexibility, long lifetime, and low manufacturing cost. Engineering the proper band structures of such layered materials is essential to realize such potential. Here, we present a plasma-assisted doping approach for significantly improving the photovoltaic response in multilayer MoS2.

Multibit data storage states formed in plasma-treated MoS₂ transistors.

New multibit memory devices are desirable for improving data storage density and computing speed. Here, we report that multilayer MoS2 transistors, when treated with plasmas, can dramatically serve as low-cost, nonvolatile, highly durable memories with binary and multibit data storage capability. We have demonstrated binary and 2-bit/transistor (or 4-level) data states suitable for year-scale data storage applications as well as 3-bit/transistor (or 8-level) data states for day-scale data storage.

MoS2 transistors fabricated via plasma-assisted nanoprinting of few-layer MoS2 flakes into large-area arrays.

Large-area few-layer-MoS2 device arrays are desirable for scale-up applications in nanoelectronics. Here we present a novel approach for producing orderly arranged, pristine few-layer MoS2 flakes, which holds significant potential to be developed into a nanomanufacturing technology that can be scaled up. We pattern bulk MoS2 stamps using lithographic techniques and subsequently transfer-print prepatterned MoS2 features onto pristine and plasma-charged SiO2 substrates.

Transport characteristics of multichannel transistors made from densely aligned sub-10 nm half-pitch graphene nanoribbons.

Densely aligned sub-10 nm graphene nanoribbons are desirable for scale-up applications in nanoelectronics. We implemented directed self-assembly of block-copolymers in combination with nanoimprint lithography to pattern sub-10 nm half-pitch nanoribbons over large areas. These graphene nanoribbons have the highest density and uniformity to date.