Title: Exploring Shortwave Infrared Surface Plasmons in 2D MXene Structures
Abstract: MXenes represent a rapidly expanding family of 2D materials. Currently, over 2000 institutions across approximately 90 countries are delving into their potential. Distinctly positioned among 2D materials, which predominantly consist of semiconductors or semimetals, MXenes stand out due to their remarkable properties of metallic conductivity, plasmonic properties, strength, and solubility. Such attributes have paved the way for a multitude of applications across diverse domains, from energy storage and telecommunications to electromagnetic shielding, sensing, and transparent electronics. However, while there has been notable progress in MXene research, the domain of MXene-based optical applications remains nascent, teeming with a wealth of untapped potential for groundbreaking discoveries and innovations.
In this presentation, we will delve into a pivotal discovery related to the optical properties of MXenes. We unearthed that the 2D Ti3C2Tx showcases a pronounced plasmon resonance in the short-wave infrared spectrum (with wavelengths spanning 1.5 - 6.0 μm) facilitated by acoustic plasmon modes. Astonishingly, this leads to a reduction in wavelength by two orders of magnitude when juxtaposed with free space. Building on this discovery, we've managed to record a nonlinear absorption coefficient of an impressive 1.37 × 10-2 m/W at a wavelength of 1.56 μm. This stellar performance can be credited to MXene's high plasma frequency, stemming from its heightened electron density, coupled with its inherent optical nonlinearity, a byproduct of its 2D structure and interspersed air gaps between the 2D layers.
Reference
[1] C. Park et al. "Ultrahigh nonlinear responses from acoustic MXene plasmons in the short-wave infrared range," submitted.