Observation of anisotropic interlayer Raman modes in few-layer ReS2

摘要: ReS$_2$ has recently emerged as a new member in the rapidly growing family of two-dimensional materials. Unlike MoS$_2$ or WSe$_2$, optical and electrical properties are not isotropic due to reduced symmetry crystal. Here, we present layer-dependent Raman measurements samples ranging from monolayers ten layers ultralow frequency regime. We observe layer breathing shear modes which allow for easy assignment number layers. Polarization-dependent give further insight into crystal structure reveal an energetic shift mode stems in-plane anisotropy modulus this material.