Suppression of thermal transport in bent boron arsenide nanoribbons

Boron arsenide (BAs) has emerged as a strong contender for next-generation functional materials, boasting desirable attributes such as high thermal conductivity and ambipolar mobility. However, a critical yet underexplored challenge lies in understanding its heat conduction capabilities under inhomogeneous strain, which is pivotal across various functional devices and operational conditions. Here, through modeling thermal transport in bent BAs and Si nanoribbons, a striking difference is revealed. Namely, the BAs nanoribbons exhibit nearly twice the reduction in thermal conductivity compared with Si under identical bending conditions. This significant disparity is driven by two key factors: the pronounced effect of phonon-spectra broadening under strain and the inhomogeneous strain-induced narrowing of the acoustic and optical (ao) gap. Together, these factors relax the originally restricted phonon scattering phase space and fundamentally alter phonon scattering dynamics. Our findings not only offer a new perspective on how heat transfer can be dynamically modulated in BAs, but also provide crucial insights into enhancing thermal performance in BAs-based functional devices.