Anisotropic Phonon Dynamics and Directional Transport in Actinide Van der Waals Semiconductor Uranium Triselenide

Direction‐dependent charge transport and optical responses are characteristic of van der Waals (vdW) materials with strong in‐plane anisotropy. While transition‐metal trichalcogenides (TMTCs) exemplify this behavior, heavier analogs remain largely unexplored. In this study, uranium triselenide (USe 3 ) is investigated as an anisotropic vdW material and a heavier analog of the well‐studied TMTCs. Strong in‐plane anisotropy is revealed using polarization‐resolved Raman spectroscopy, strain‐induced shifts of phonon modes are investigated, and direction‐dependent charge‐carrier mobility is quantified through transport measurements on field‐effect devices. First‐principles calculations based on density functional theory corroborate these findings, providing a theoretical basis for the experimental observations. Casting USe 3 as an actinide analog of a TMTC establishes a platform for exploring low‐dimensional semiconductors that combine strong in‐plane anisotropy with f ‐electron physics.