In-Plane Lattice Deformation Reshapes Interfacial Thermal Transport and Stability Limits in van der Waals Heterostructures.

Efficient heat dissipation across van der Waals (vdW) interfaces is a long-standing challenge in two-dimensional (2D) heterostructures, where cross-plane thermal transport is commonly regarded as an intrinsic and quasi-static interface property dictated by weak interlayer coupling and fixed interfacial geometry. As a result, vdW interfaces are typically viewed as passive thermal bottlenecks that can only be modified through direct chemical or structural engineering. Here, we demonstrate this view is incomplete. We show that in-plane lattice deformation can reversibly reshape cross-plane interfacial thermal transport without directly perturbing the interface itself. Using high-quality MoS2/WS2 heterobilayers, we experimentally observe that a modest in-plane tensile strain (∼1.6%) enhances interfacial thermal conductance by approximately 50%, with excellent reproducibility across independent samples and full reversibility over multiple strain-release cycles. Molecular dynamics simulations reveal that this enhancement originates from strain-induced interfacial compliance, characterized by contraction of the vdW gap, stiffening of interlayer force constants, and strengthened elastic phonon transmission. Importantly, strain-enhanced interfacial heat transport increases the critical absorbed power density prior to thermal degradation, indicating that mechanical deformation effectively shifts the apparent thermal stability threshold by reconfiguring heat-dissipation pathways. This work establishes in-plane mechanical deformation as a noninvasive and dynamically controllable method for reshaping interfacial heat transport and associated stability limits in vdW heterostructures, providing a scalable route toward adaptive thermal management in 2D material-based electronic architectures.