Resolving Interface Barrier Deviation from the Schottky-Mott Rule: A Mitigation Strategy via Engineering MoS 2 -Metal van der Waals Contact.

The Schottky barrier (SB) in the ultraclean van der Waals contact between two-dimensional (2D) MoS 2 and three-dimensional (3D) indium (In) strikingly deviates from the Schottky-Mott limit (SML). Herein, on the basis of first-principles calculation, the origin of the SB deviation is brought to bear, as well as a strategy for mitigating the SB deviation. In light of the good agreement between the SB and the corrected SB by interface potential difference (Δ V ) and Fermi -level shift (Δ E F ) based on the SML, the SB deviation is attributed to the combined effects of Δ V and Δ E F . Furthermore, when a Au, Sc, or Ti thin film is coated on the back side of In, the SB deviation and the sum of Δ V and Δ E F decrease similarly. Importantly, in the Ti coating situation, the SB is reduced to 0.12 eV, notably smaller than the value of 0.30 eV in the Au coating case. This interface engineering can be generalized to regulate the SB between a 2D semiconductor and a 3D alloy.