Rhenium Diselenide (ReSe₂)

ReSe₂ is a rhenium-based dichalcogenide closely related to ReS₂ in structure, also adopting a triclinic distorted 1T′ phase with space group P-1, in which the Re atoms likewise form Re₄ clusters, producing strong in-plane anisotropyand weak interlayer coupling. Compared with ReS₂, the larger atomic radius and lower electronegativity of selenium (Se) result in narrower energy bands and an indirect bandgap of about 1.2–1.3 eV, extending its photoresponse into the near-infrared range. Its anisotropic optoelectronic and vibrational properties have attracted attention for anisotropic photodetection, field-effect transistors, and polarization-sensitive light sensing.