Enhancing Hole Mobility in Monolayer WSe<sub>2</sub> p-Type Field-Effect Transistors via Process-Induced Compression.

Zhao, He Lin; Ta-Seen Afrid, Sheikh Mohd; Yoon, Dongyoung; Martin, Zachary; Islam, Zakaria; Chen, Sihan; Zhang, Yue; Huang, Pinshane Y et al. · ACS Nano · 2026

basic_science · Level V

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Abstract

Understanding the interactions between strain, interfacial mechanics, and electrical performance is critical for designing beyond-silicon electronics based on heterointegrated 2D materials. Through combined experiment and simulation, we demonstrated and analyzed the enhancement of hole mobility in p-type monolayer WSe<sub>2</sub> field effect transistors (FETs) under biaxial compression. We tracked FET performance versus strain by incrementing compressive strain to WSe<sub>2</sub> channels via sequential AlO<sub><i>x</i></sub> deposition and performing intermediate photoluminescence and transport measurements. The hole mobility factor <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mrow><mo>(</mo><mi>μ</mi><mo>/</mo><msub><mi>μ</mi><mn>0</mn></msub><mo>)</mo></mrow><mrow><mi>p</mi><mo>,</mo><mrow><mi>F</mi><mi>E</mi></mrow></mrow></msub></math> increased at a rate of 340 ± 95%/%ε, and the on-current factor (<i>I</i><sub>on</sub>/<i>I</i><sub>on,0</sub>) increased at a rate of 460 ± 340%/%ε. Simulation revealed that the enhancement under compression arises primarily from a reduction in intervalley scattering between the Γ-<i>K</i> valence bands, and the rate is robust against variations in carrier density, impurity density, or dielectric environment. These findings show that compressive strain is a powerful technique for enhancing performance in 2D p-FETs and that it is multiplicative with defect and doping engineering.