Controllable growth of substrate-scale 2D ReSe 2 thin films and their application for molecular detection via the SERS technique.

Rhenium diselenide (ReSe 2 ) has attracted great interest due to its unique anisotropic structure and unusual in-plane anisotropic electrical and optical properties. However, efficient fabrication of large-area and high-quality 2D ReSe 2 continuous films has become an increasingly important challenge. In this work, centimeter-scale 2D ReSe 2 continuous films with the layer number varying from monolayer to 12 layers were successfully grown on a mica substrate using our space-confined CVD system via changing the position of the substrate. The fluorescence quenching effect and surface enhanced Raman scattering (SERS) effect on 2D ReSe 2 films with different layer numbers were investigated using rhodamine 6G (R6G) dye molecules as a Raman probe. The large-area ReSe 2 films show the layer-number-dependent nature of the SERS effect and a robust suppression effect of fluorescence. Our work explores the practical application of 2D ReSe 2 films for molecular detection via the SERS technique.