Revealing the Optical Anisotropy of ReS2 Nanostructures by Strain Engineering

Two-dimensional (2D) anisotropic materials possess asymmetricatomicarrangements and normally exhibit physicochemical properties distinguishablyalong different crystal orientations, offering a brand-new degreeof freedom for fabricating conceptual devices. Developing a feasiblestrain loading method for materials with nonorthogonal crystallineaxes is necessary, enabling a deeper understanding of the 2D anisotropyof such materials, which is of valuable guidance for the optimizationof optoelectronic devices. Here, we proposed a uniaxial strain loadingmethod by rotation and examined the trend of optical properties ofanisotropic ReS2 under strain applied along the a- and b-axis strain directions. From theRaman and photoluminescence spectra, it can be seen that the vibrationaland optical responses achieve the maximum under the strain that isapplied uniaxially along the crystalline b-axis.Our work provides a reliable strategy to tailor the anisotropic opticalproperties, making it feasible to selectively improve the materialperformance of ReS2 nanostructures-based optoelectronicand logic devices in the future.