Large-area and highly crystalline CVD-grown multilayer MoSe2 films exhibit a well-defined crystal structure (2H phase) and large grains reaching several hundred micrometers. Multilayer MoSe2 transistors exhibit high mobility up to 121 cm(2) V(-1) s(-1) and excellent mechanical stability. These results suggest that high mobility materials will be indispensable for various future applications such as high-resolution displays and human-centric soft electronics.

Transition metal dichalcogenides (TMDs) layers of molecular thickness, in particular molybdenum disulfide (MoS2), become increasingly important as active elements for mechanically flexible/stretchable electronics owing to their relatively high carrier mobility, wide bandgap, and mechanical flexibility. Although the superior electronic properties of TMD transistors are usually integrated into rigid silicon wafers or glass substrates, the achievement of similar device performance on flexible substrates remains quite a challenge. The present work successfully addresses this challenge by a novel process architecture consisting of a solution‐based polyimide (PI) flexible substrate in which laser‐welded silver nanowires are embedded, a hybrid organic/inorganic gate insulator, and multilayers of MoS2. Transistors fabricated according to this process scheme have decent properties: a field‐effect‐mobility as high as 141 cm2 V−1 s−1 and an Ion/Ioff ratio as high as 5 × 105. Furthermore, no apparent degradation in the device properties is observed under systematic cyclic bending tests with bending radii of 10 and 5 mm. Overall electrical and mechanical results provide potentially important applications in the fabrication of versatile areas of flexible integrated circuitry.

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Multilayer MoS 2 is a promising active material for sensing, energy harvesting, and optoelectronic devices owing to its intriguing tunable electronic band structure. However, its optoelectronic applications have been limited due to its indirect band gap nature. In this study, we fabricated a new type of phototransistor using multilayer MoS 2 crystal hybridized with p-type organic semiconducting rubrene patches. Owing to the outstanding photophysical properties of rubrene, the device characteristics such as charge mobility and photoresponsivity were considerably enhanced to an extent depending on the thickness of the rubrene patches. The enhanced photoresponsive conductance was analyzed in terms of the charge transfer doping effect, validated by the results of the nanoscale laser confocal microscope photoluminescence (PL) and time-resolved PL measurements.

We present a systematic investigation of polyethylenimine (PEI) doping mechanism and its effects on the multilayer MoS2 field effect transistors (FETs). The threshold voltages of MoS2 FETs before (i.e., pristine) and PEI doping are observed at 3.7 and 0.72 V, respectively. This negative threshold voltage shift clearly reveals that the PEI molecules effectively act as n‐type dopants. The electrical properties are improved by absorption of PEI molecules onto MoS2 channel because the width of Schottky barrier (SB) is narrowed by the induced interfacial dipole between PEI molecules and MoS2 layers. Through the density function theory (DFT) calculation and X‐ray photoelectron spectroscopy (XPS) analysis, we confirm that formation of MoN bond generates new energy state into the bandgap. Consequently, the hole carriers can easily tunnel through the barrier under negative gate voltage. Furthermore, PEI doping improve photoresponsivity and time‐resolved photo‐switching characteristics because of the new energy state. Our studies demonstrate the PEI doping method has a great potential for improving electrical and optical properties of MoS2‐based devices.