Unleashing 2D MXene's Plasmonic Effect for Advanced Photonic Device Applications

MXenes, the largest family of 2D transition metal carbides/nitrides, have emerged as promising materials for various applications due to their exceptionally fascinating properties. In this study, the potential of MXenes is investigated in plasmonic applications, particularly focusing on surface-enhanced Raman scattering (SERS) and broadband photodetection. The study explored a broader range of light-matter interactions based on edge plasmons that emerge at sub-monolayer coverage of MXene, while existing studies have primarily focused on thicknesses exceeding tens of nanometers. Additionally, by incorporating MXenes onto 3D trench nanostructures, To maximize their plasmonic properties is aimed by enhancing the manifestation of edge plasmons, leading to intensified light amplification. The fabricated opto-electronic devices exhibit remarkable sensitivity in SERS detection, achieving a detection limit as low as ≈0.1 nm for the target dye molecule, significantly surpassing typical thresholds for non-metal-based detection. Additionally, the enhancement factor exceeds that of commercially available Au-based SERS substrates. Furthermore, MXene-based photodetectors demonstrate competitive photoresponsivity and response time, particularly toward the near-infrared (NIR) wavelength bands, which are challenging to achieve with MXene-based photodetectors. Through a comprehensive analysis, including electric field calculations, the mechanisms driving the observed enhancements are unveiled, primarily attributing them to edge plasmons.