Mobility enhancement and highly efficient gating of monolayer MoS2 transistors with Polymer Electrolyte
Ming‐Wei Lin, Lezhang Liu, Qing Lan, Xuebin Tan, Kulwinder Dhindsa, Peng Zeng, V. M. Naik, Mark Ming‐Cheng Cheng, Zhixian Zhou · arXiv (Cornell University) · 2012
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.