Record high current density and low contact resistance in MoS2 FETs by ion doping

Record high current density of 300 μA/μm with low contact resistance of 200 Ω μm and a channel length of 0.8 μm at a drain-source bias of 1.6 V has been achieved for the first time in MoS2 field-effect transistors (FETs) grown by chemical vapor transport. The low contact resistance is achieved using a polyethylene-oxide cesium-perchlorate solid polymer ion conductor formed by drop casting. The charged ions are placed into position over the channel by the application of a bias to a side gate and then locked into place by lowering the temperature. A weak temperature dependence of the drain current after ion doping indicates that transport in the Schottky contacts is dominated by tunneling.