Hidden phonon highways promote photoinduced interlayer energy transfer in twisted transition metal dichalcogenide heterostructures.

ABSTRACT: Vertically stacked van der Waals (vdW) heterostructures exhibit unique electronic, optical, and thermal properties that can be manipulated by twist-angle engineering. However, the weak phononic coupling at a bilayer interface imposes a fundamental thermal bottleneck for future two-dimensional devices. Using ultrafast electron diffraction, we directly investigated photoinduced nonequilibrium phonon dynamics in MoS₂/WS₂ at 4° twist angle and WSe₂/MoSe₂ heterobilayers with twist angles of 7°, 16°, and 25°. We identified an interlayer heat transfer channel with a characteristic timescale of ~20 picoseconds, about one order of magnitude faster than molecular dynamics simulations assuming initial intralayer thermalization. Atomistic calculations involv

SUBMITTER: Johnson AC 

PROVIDER: S-EPMC10807799 | biostudies-literature | 2024 Jan

REPOSITORIES: biostudies-literature