Surface-enhanced Raman scattering on sandwiched structures with gallium telluride

Two-dimensional crystals-based surface-enhanced Raman scattering (SERS) substrates are a research hot spot in the realm of chemistry and biology. Herein, a novel hybrid substrate based on AuNPs/GaTe/Au-film is proposed and fabricated for SERS activity. Finite-difference time-domain numerical simulations demonstrate that the plasmonic coupling in the hybrid structure, particularly the LSPs coupling of AuNPs and Au-film, promotes an enhanced electric field and consequently, greatly enhances the Raman activity. Impressively, the enhancement factor of 3 × 10⁵ and the limiting detection concentration of 10⁻¹⁴ M have been achieved for the rhodamine 6G molecules, which are equivalent to the best results achieved from the patterned graphene substrates. Due to its simple structure, cost-effectiveness, good uniformity, reproducibility, and stability, it is expected that such a SERS substrate will open up a new way toward the ultrasensitive detection of molecules.