Strain-Enhanced\nMobility of Monolayer MoS₂

Abstract

Strain engineering is an important method for tuning\nthe properties\nof semiconductors and has been used to improve the mobility of silicon\ntransistors for several decades. Recently, theoretical studies have\npredicted that strain can also improve the mobility of two-dimensional\n(2D) semiconductors, e.g., by reducing intervalley scattering or lowering\neffective masses. Here, we experimentally show strain-enhanced electron\nmobility in monolayer MoS₂ transistors with uniaxial tensile\nstrain, on flexible substrates. The on-state current and mobility\nare nearly doubled with tensile strain up to 0.7%, and devices return\nto their initial state after release of the strain. We also show a\ngate-voltage-dependent gauge factor up to 200 for monolayer MoS₂, which is higher than previous values reported for sub-1\nnm thin piezoresistive films. These results demonstrate the importance\nof strain engineering 2D semiconductors for performance enhancements\nin integrated circuits, or for applications such as flexible strain\nsensors.