Local-gate electrical actuation, detection, and tuning of atomic-layer M0S2 nanoelectromechanical resonators

We report on the first single- and few-layer molybdenum disulfide (MoS
₂
) nanoelectromechanical resonators with local electrical gate, and the demonstration of local-gate all-electrical actuation, detection, and tuning of the atomic-layer MoS
₂
resonators at very high frequency (VHF). These local-gate structures make MoS
₂
vibrating-channel transistors (VCTs), and facilitate efficient frequency modulation (FM) electrical readout and local-gate resonance tuning of individual VCTs. The resonant responses are also verified by optical motion detection techniques. We have scaled down the dimensions of these VCTs to length (L) of 800 nm and air gap (g) of 170 nm in the suspended MoS
₂
region, attaining fundamental-mode resonance frequency (f
₀
) up to 130 MHz, and local-gate electrical tuning up to Δf
₀
/f
₀
~ 13%. The layer numbers of these MoS
₂
devices are confirmed by their unique Raman and photoluminescence (PL) signatures. These local-gate devices establish the foundation for all-electrical readout of MoS
₂
resonators and their arrays, toward multiplexing of individually addressable devices, which could enable arraying and large-scale integration of atomic-layer resonant systems for parallel signal transduction and resonance-based sensing.