Molybdenum disulfide (MoS2) is a layered semiconducting material with a tunable bandgap that is promising for the next generation nanoelectronics as a substitute for graphene or silicon. Despite recent progress, the synthesis of high‐quality and highly uniform MoS2 on a large scale is still a challenge. In this work, a temperature‐dependent synthesis study of large‐area MoS2 by direct sulfurization of evaporated Mo thin films on SiO2 is presented. A variety of physical characterization techniques is employed to investigate the structural quality of the material. The film quality is shown to be similar to geological MoS2, if synthesized at sufficiently high temperatures (1050 °C). In addition, a highly uniform growth of trilayer MoS2 with an unprecedented uniformity of ±0.07 nm over a large area (> 10 cm2) is achieved. These films are used to fabricate field‐effect transistors following a straightforward wafer‐scale UV lithography process. The intrinsic field‐effect mobility is estimated to be about 6.5±2.2 cm2 V–1 s–1 and compared to previous studies. These results represent a significant step towards application of MoS2 in nanoelectronics and sensing.

Atomically thin molybdenum disulfide (MoS2) is a promising two-dimensional semiconductor for high-performance flexible electronics, sensors, transducers, and energy conversion. Here, piezoresistive strain sensing with flexible MoS2 field-effect transistors (FETs) made from highly uniform large-area films is demonstrated. The origin of the piezoresistivity in MoS2 is the strain-induced band gap change, which is confirmed by optical reflection spectroscopy. In addition, the sensitivity to strain can be tuned by more than 1 order of magnitude by adjusting the Fermi level via gate biasing.

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Large area chemical vapor deposited graphene and hexagonal boron nitride was used to fabricate graphene-hexagonal boron nitride-graphene symmetric field effect transistors. Gate control of the tunneling characteristics is observed similar to previously reported results for exfoliated graphene-hexagonal boron nitride-graphene devices. Density-of-states features are observed in the tunneling characteristics of the devices, although without large resonant peaks that would arise from lateral momentum conservation. The lack of distinct resonant behavior is attributed to disorder in the devices, and a possible source of the disorder is discussed.

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