title: Phase-engineered low-resistance contacts for ultrathin MoS2 transistors.
abstract: Ultrathin molybdenum disulphide (MoS2) has emerged as an interesting layered semiconductor because of its finite energy bandgap and the absence of dangling bonds. However, metals deposited on the semiconducting 2H phase usually form high-resistance (0.7 kΩ μm-10 kΩ μm) contacts, leading to Schottky-limited transport. In this study, we demonstrate that the metallic 1T phase of MoS2 can be locally induced on semiconducting 2H phase nanosheets, thus decreasing contact resistances to 200-300 Ω μm at zero gate bias. Field-effect transistors (FETs) with 1T phase electrodes fabricated and tested in air exhibit mobility values of ~50 cm(2) V(-1) s(-1), subthreshold swing values below 100 mV per decade, on/off ratios of >10(7), drive currents approaching ~100 μA μm(-1), and excellent current saturation. The deposition of different metals has limited influence on the FET performance, suggesting that the 1T/2H interface controls carrier injection into the channel. An increased reproducibility of the electrical characteristics is also obtained with our strategy based on phase engineering of MoS2.
authors.affiliation: Materials Science and Engineering, Rutgers University, 607 Taylor Road, Piscataway, New Jersey 08854, USA.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Kappera
authors.affiliation: Materials Science and Engineering, Rutgers University, 607 Taylor Road, Piscataway, New Jersey 08854, USA.
authors.forename: Damien
authors.initials: D
authors.lastname: Voiry
authors.affiliation: MPA-11 Materials Synthesis and Integrated Devices, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Sibel Ebru
authors.initials: SE
authors.lastname: Yalcin
authors.affiliation: MPA-11 Materials Synthesis and Integrated Devices, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Brittany
authors.initials: B
authors.lastname: Branch
authors.affiliation: MPA-11 Materials Synthesis and Integrated Devices, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Gautam
authors.initials: G
authors.lastname: Gupta
authors.affiliation: MPA-11 Materials Synthesis and Integrated Devices, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Aditya D
authors.initials: AD
authors.lastname: Mohite
authors.affiliation: Materials Science and Engineering, Rutgers University, 607 Taylor Road, Piscataway, New Jersey 08854, USA.
authors.forename: Manish
authors.initials: M
authors.lastname: Chhowalla