Biaxial Tensile Strain Enhances Electron Mobility of Monolayer Transition Metal Dichalcogenides

Abstract

Strain engineering can modulate the material properties of two-dimensional (2D) semiconductors for electronic and optoelectronic applications. Recent theory and experiments have found that uniaxial tensile strain can improve the electron mobility of monolayer MoS${}_2$, a 2D semiconductor, but the effects of biaxial strain on charge transport are not well-understood in 2D semiconductors. Here, we use biaxial tensile strain on flexible substrates to probe the electron mobility in monolayer WS${}_2$ and MoS${}_2$ transistors. This approach experimentally achieves ~2x higher on-state current and mobility with ~0.3% applied biaxial strain in WS${}_2$, the highest mobility improvement at the lowest strain reported to date. We also examine the mechanisms behind this improvement through density functional theory simulations, concluding that the enhancement is primarily due to reduced intervalley electron-phonon scattering. These results underscore the role of strain engineering 2D semiconductors for flexible electronics, sensors, integrated circuits, and other optoelectronic applications.

Corrected author list

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Cited by in corpus (6)

• CMOS-compatible Strain Engineering for High-Performance Monolayer Semiconductor Transistors
• Signatures of valley drift in the diversified band dispersions of bright, gray, and dark excitons in MoS2 monolayers under uni-axial strains
• Transconductance as a Probe of Valley Thermodynamics in Multilayer WSe${}_2$
• Tuning Terahertz Optomechanics of MoS2 Bilayers with Homogeneous In-plane Strain
• Mechanical Detuning of Exciton-Phonon Resonance in WS2
• Angular Emission Properties of Strained Transition-Metal Dichalcogenides