One-Step Fabrication Method of MoS₂for High-Performance Surface-Enhanced Raman Scattering

A one-step method was proposed to prepare a high-performance surface-enhanced Raman scattering (SERS) substrate based on bulk MoS₂via femtosecond laser pulse modification. The Raman spectra of Rhodamine 6G (R6G) molecules were measured on different laser fluence treatment substrates with various solution concentrations. The most optimized laser-treated MoS₂substrate showed a large Raman enhancement factor of 1.67 × 10⁵and extremely high sensitivity for detection of R6G molecules, even down to 10^-8M. The morphology characterization, photoluminescence measurement, and electromagnetic simulation were used to reveal the laser treatment-dependent Raman enhancement mechanism. The results indicated that the p-doping effect induced by oxygen absorption led to holes filling on the top of the valence band after the laser treatment, which can enhance the charge transfer between MoS₂and R6G molecules and finally lead to the SERS effect. This method can provide a high-performance and cost-efficient way to prepare SERS substrates.