Moiré superlattice distortion–driven superlubricity via interfacial energy barrier modulation in twisted transition metal dichalcogenides

Superlubricity in two-dimensional van der Waals materials arises from moiré superlattices (MSL) that suppress sliding friction via periodic potential cancellation. However, a structure–property correlation linking the geometric and physical characteristics of MSL distortions to sliding energy barrier and tribological performance remains lacking. Here, the tribological performances of bilayer transition metal dichalcogenides (TMDs) including MoS₂, WS₂, MoSe₂, and WSe₂ are systematically investigated at twist angles of 0°, 13.17°, 21.79°, and 32.20°. The results demonstrate that the sliding energy barrier is governed by the interplay among MSL-induced lattice distortion, electronic localization, and interlayer-spacing modulation. Specifically, the intrinsic bonding strength is found to be highly sensitive to both chalcogen species and twist angles. While Se-containing systems exhibit stronger intralayer electron localization and enhanced interlayer charge-density fluctuations, S-based systems display comparatively weaker electronic modulation. At 13.17°, pronounced d-orbital localization strengthens interlayer coupling, resulting in the highest sliding energy barriers. In contrast, at 21.79° and 32.20°, the reduced area of strongly coupled stacking regions, together with the enlarged interlayer spacing, weakens interlayer interactions, thereby facilitating low-energy sliding pathways. Accordingly, WS₂ at 32.20° is predicted to exhibit the lowest sliding barrier, owing to an optimal balance between charge localization and interlayer separation. By establishing a quantitative correlation among sliding energy barriers, interfacial orientations, and material compositions, this study elucidates the MSL-driven lubrication mechanism and provides theoretical guidance for the rational design of advanced lubricants.