We demonstrated highly stable multilayer molybdenum disulfide (MoS2) field-effect transistors (FETs) with negligible hysteresis gap (ΔV(HYS) ∼ 0.15 V) via a multiple annealing scheme, followed by systematic investigation for long-term air stability with time (∼50 days) of MoS2 FETs with (or without) CYTOP encapsulation. The extracted lifetime of the device with CYTOP passivation in air was dramatically improved from 7 to 377 days, and even for the short-term bias stability, the experimental threshold voltage shift, outstandingly well-matched with the stretched exponential function, indicates that the device without passivation has approximately 25% larger the barrier distribution (ΔE(B) = k(B)T(o)) than that of a device with passivation. This work suggests that CYTOP encapsulation can be an efficient method to isolate external gas (O2 and H2O) effects on the electrical performance of FETs, especially with low-dimensional active materials like MoS2.

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This paper investigates the low-frequency noise properties of multilayer WSe2 field effect transistors (FETs) in subthreshold, linear, and saturation regime. The measured noise power spectral density of drain current (SID) shows that the low-frequency noise in multilayer WSe2 FET fits well to a 1/fγ power law with γ ∼ 1 in the frequency range of 10 Hz–200 Hz. From the dependence of SID on the drain current, carrier mobility fluctuation is considered as a dominant low frequency noise mechanism from all operation regimes in multilayer WSe2 FET. Extracted Hooge's parameter in this study is within the value of 0.12, comparable to those of the transition metal dichalcogenide FETs in recent reports.

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