Strain-controlled phonon transport in van der Waals hetero-structures: a quantum study

Abstract We investigate phonon transport in strained van der Waals heterostructures using a first-principles nonequilibrium Green’s function (NEGF) approach. For monolayer MoS 2 , biaxial and uniaxial in-plane strains strongly modify phonon dispersion and transmission. Compressive strain stiffens the lattice and enhances thermal transport, resulting in a 24.10% increase in thermal conductivity under 8% biaxial compression, whereas tensile strain induces phonon softening and suppresses thermal transport by up to 10.93%. These trends are quantitatively linked to strain-induced changes in the harmonic dynamical matrix and are dominated by low-frequency acoustic phonons. For bilayer MoS 2 and MoS 2 /WS 2 heterobilayers, we examine in-plane tensile strain and cross-plane compression by varying the interlayer distance. The bilayer thermal conductance remains close to the additive monolayer limit, demonstrating that intralayer interactions dominate phonon transport, while interlayer van der Waals coupling plays a minor role. In-plane strain produces a much stronger modulation of thermal conductance than cross-plane compression, indicating that strain engineering provides an efficient route for tuning heat transport in layered transition-metal dichalcogenides (TMDs) for nanoscale thermal management and device optimization.