Improving carrier mobility in two-dimensional semiconductors with rippled materials

Two-dimensional (2D) semiconductors could potentially replace silicon in future electronic devices. However, the low carrier mobility in 2D semiconductors at room temperature, caused by strong phonon scattering, remains a critical challenge. Here we show that lattice distortions can reduce electron–phonon scattering in 2D materials and thus improve the charge carrier mobility. We introduce lattice distortions into 2D molybdenum disulfide (MoS2) using bulged substrates, which create ripples in the 2D material leading to a change in the dielectric constant and a suppressed phonon scattering. A two orders of magnitude enhancement in room-temperature mobility is observed in rippled MoS2, reaching ∼900 cm2 V−1 s−1, which exceeds the predicted phonon-limited mobility of flat MoS2 of 200–410 cm2 V−1 s−1. We show that our approach can be used to create high-performance room-temperature field-effect transistors and thermoelectric devices.Agency for Science, Technology and Research (A*STAR)National Research Foundation (NRF)Submitted/Accepted versionJ.W. acknowledges the SERC Central Research Fund (CRF KIMR211001kSERCRF) and Advanced Manufacturing and Engineering Young Individual Research Grant (AME YIRG grant no. A2084c170). D.C. and J.W. acknowledge National Research Foundation Competitive Research Programs (NRFCRP24-2020-0002). M.Y. acknowledges funding support (project IDs 1-BE47, ZE0C, ZE2F and ZE2X) from The Hong Kong Polytechnic University. K.H. acknowledges funding from the Accelerated Materials Development for Manufacturing Program at the Agency for Science, Technology and Research (A*STAR) via the AME Programmatic Fund under grant no. A1898b0043. D.X. and T.L. acknowledge the Young Scientist project of the MOE Innovation platform. D.X. acknowledges the National Natural Science Foundation (NSF) of China (grant no. 62104041) and Shanghai Sailing Program (grant no. 21YF1402600). T.L. acknowledges the NSF of Shanghai (grant no. 22ZR1405700)