We report electrical characterization of monolayer molybdenum disulfide (MoS2) devices using a thin layer of polymer electrolyte consisting of poly(ethylene oxide) (PEO) and lithium perchlorate (LiClO4) as both a contact-barrier reducer and channel mobility booster. We find that bare MoS2 devices (without polymer electrolyte) fabricated on Si/SiO2 have low channel mobility and large contact resistance, both of which severely limit the field-effect mobility of the devices. A thin layer of PEO/ LiClO4 deposited on top of the devices not only substantially reduces the contact resistance but also boost the channel mobility, leading up to three-orders-of-magnitude enhancement of the field-effect mobility of the device. When the polymer electrolyte is used as a gate medium, the MoS2 field-effect transistors exhibit excellent device characteristics such as a near ideal subthreshold swing and an on/off ratio of 106 as a result of the strong gate-channel coupling.
@article{arxiv.1207.4824,
title = {Mobility enhancement and highly efficient gating of monolayer MoS2 transistors with Polymer Electrolyte},
author = {Ming-Wei Lin and Lezhang Liu and Qing Lan and Xuebin Tan and Kulwinder Dhindsa and Peng Zeng and Vaman M. Naik and Mark Ming-Cheng Cheng and Zhixian Zhou},
journal= {arXiv preprint arXiv:1207.4824},
year = {2015}
}