Strain Engineering of MoS2 for Overcoming Thermal Bottlenecks in Next-Generation Energy-Efficient Electronics.

The relentless demand for energy-efficient electronics creates a critical thermal bottleneck. A long-standing paradigm holds that compressive strain universally degrades thermal transport in two-dimensional (2D) materials by inducing phonon-scattering wrinkles. Here, we overturn this in MoS2 by demonstrating that substrate-confined, wrinkle-free compression drastically enhances its in-plane thermal conductivity. This feature is achieved through a substrate confinement strategy that enables uniform, wrinkle-free compression. We experimentally measured a remarkable 40% boost in thermal conductivity with merely 1% compressive strain, an effect that starkly contrasts with the suppression observed under tension. Molecular dynamics simulations reveal that the substrate suppresses out-of-plane instabilities via van der Waals coupling, facilitating an unprecedented strain transfer. First-principles calculations further reveal that the compressive strain reconfigures the crystal symmetry, concurrently increasing phonon group velocities and prolonging phonon lifetimes. This work resolves a critical bottleneck in 2D thermal management and unlocks a new pathway for the atomic-scale design of high-thermal conductivity materials for next-generation electronics.