Alignment Relation between a Nematic Liquid Crystal and ReS₂ Nanosheets: Implications for Anisotropic Optoelectronic Applications

Rhenium disulfide (ReS 2 ), a two-dimensional (2D) semiconductor, exhibits unique anisotropic properties rarely found in other 2D materials. This study investigates the alignment characteristics of nematic liquid crystals on ReS 2 nanosheet using optical texture analysis, transmission measurements, and Raman scattering techniques. For the b → and c →, crystal basis vectors of ReS 2, the director ( n ^ 0 ) aligned along the easy axis satisfies equations, n ^ 0 · ( c → × b → ) > 0 and n ^ 0 · b → = | b → | cos ( θ ) > 0 with θ = 15°. Both polar and azimuthal anchoring strengths were found to be very weak, with extrapolation lengths on the order of several micrometers. Additionally, the orientation of the ReS 2 nanosheets suspended in the nematic liquid crystal is effectively controlled through electric field application and director manipulation. The ability to control the orientation of ReS 2 nanosheets through several methods suggests that the anisotropic properties of ReS 2 can be effectively tuned to different values for switching applications. This capability opens up possibilities for leveraging the unique directional characteristics of ReS 2 in devices that require precise orientation-dependent control.