Conductivity modulation in strained transition-metal-dichalcogenides via micro-electro-mechanical actuation

In this work, strain-induced conductivity modulation in bi-layer molybdenum disulfide (MoS2) flakes is experimentally investigated and modeled. Uniaxial tensile strain in the MoS2 flakes is achieved using a micro-electro-mechanical (MEM) actuator. Conductivity ratios up to 400 are demonstrated. Theoretical predictions of conductivity versus applied voltage in the MEMS-MoS2 device match experimental data reasonably well using only the effective width of the TMDC flakes as the sole fitting parameter. The amount of strain induced in the MoS2 flakes was determined to be as high as 2.7% for one flake using the model fitted to the experiment data. The switching energy required to achieve a conductivity increase of 106 is calculated as a function of device critical dimension (length of TMDC flake). The model, which takes van der Waals forces into account, predicts a switching energy of 0.34 aJ cm−2 and subthreshold swing of 17 mV/dec for a device scaled down to 10 nm.