Quasi-1D ZrS3 as an Anisotropic Nano-Reflector for Manipulating Light-Matter Interactions

2D layered materials with low crystal symmetries exhibit unique anisotropic physical properties. Here the systematic studies on the optical modulation effects of such anisotropic 2D materials to isotropic 2D materials in their stacked van der Waals (vdW) heterostructures are reported. By applying angle-resolved polarization spectroscopic characterizations on the MoS2/ZrS3 vdW heterostructure, periodic intensity variations of the Raman scattering and photoluminescence (PL) emission modes of monolayer MoS2 are observed, which are closely correlated to the anisotropic optical properties of the underlying ZrS3 layers. Such anisotropic optical modulation effects can be identified with the thickness of ZrS3 reduced to few layers (approximate to 6 nm), and are attributed to the strong birefringence and dichroism effects in ZrS3 that cause reflection difference between its crystal axis, thus modulating the Raman/PL intensities of MoS2 via Fabry-Perot interference effect. Furthermore, the polarized photocurrent response of the heterostructure is also demonstrated, where its major contribution originates from MoS2. This work develops a new methodology to tune the light-matter interactions and properties of isotropic 2D materials by the combination with anisotropic 2D materials, which substantially broadens the application of low symmetry layered materials in polarization sensitive optoelectronic devices.

Automated summary

This study systematically investigates the optical modulation effects of anisotropic 2D materials on isotropic 2D materials in stacked van der Waals heterostructures. The results show that the anisotropic optical properties of the underlying ZrS3 layers have a significant impact on the Raman/PL intensities of MoS2. These anisotropic optical modulation effects can be identified with thin ZrS3 layers due to the strong birefringence and dichroism effects. The polarized photocurrent response of the heterostructure is also demonstrated, with MoS2 as the major contributor.