MoS2 Transistor with Weak Fermi Level Pinning via MXene Contacts

Abstract The quality of the contact between source/drain electrodes and 2D transition metal dichalcogenides plays a decisive role in improving transistor performance. Understanding the mechanisms of Fermi level pinning (FLP) and finding out the strategies to solve FLP problems can further promote the development of 2D electronics. In this study, the suppressing effect of MXene on FLP in MoS 2 transistors by using Ti 3 C 2 T x as an electrode to build a Ti 3 C 2 T x ‐MoS 2 heterostructure is systematically studied. A simple and time‐saving ultraviolet ozone technique to tune the work function of the Ti 3 C 2 T x electrode in the range of 4.33–5.32 eV is proposed, and a low Schottky barrier height of 121 meV is achieved. The van der Waals contact between Ti 3 C 2 T x and MoS 2 can alleviate the FLP effectively, and the pinning factor can be greatly optimized from 0.28 (metal electrode) to 0.87 (MXene electrode). This study can pave the way for extensive use of MXene and provide a new strategy to eliminate the negative effects of FLP in 2D materials‐based electronic devices.