First-Principles Predictions of Janus MoSSe and WSSe for FET Applications

Janus transition-metal dichalcogenides (JTMDs) with an asymmetric structure have attracted much attention because of their obvious potential in electronic and optical applications. However, there are few research studies on field-effect transistors (FETs) related to JTMDs, and the inherent device transport performance is unclear so far. In this work, we systematically investigate the ballistic transport performance of sub-10 nm monolayer Janus MoSSe and WSSe metal oxide semiconductor FETs (MOSFETs) based on ab initio quantum transport simulations. The on-state current, delay time, and power dissipation of Janus MoSSe and WSSe MOSFETs with a proper doping concentration under the requirements of high performance (HP) in the International Technology Roadmap for Semiconductor are systematically studied. The calculated results indicate that the on-state currents of MoSSe MOSFETs can satisfy about 35% requirement of HP standards and the WSSe MOSFETs fulfill the HP application targets until the gate length is scaled down to 4 nm. In addition, we discussed the underlying physical mechanisms and further explored the effect of channel material oxidation on the device performance. As a result, it is believed that our predictions could greatly stimulate the potential of Janus MoSSe and WSSe applied to transistors.