Optical Properties of MXenes

In the past decade, two-dimensional (2D) materials have had a significant impact on the physics and optics research community as they are observed to interact with light in a large variety of unique ways. MXenes have been added to this class of 2D in 2011. Ever since their discovery, they have been explored by a growing number of different fields of research, including optics and nanophotonics. In relation to optics, in the past few years, researchers have demonstrated a number of widely useful and interesting features of the MXenes, for example, optical transparency, plasmonic behavior, optical nonlinearity, efficient photothermal conversion, tunability of optical response, etc. These have led to application of the MXenes in functional metamaterial devices, mode-locked lasers, surface-enhanced Raman spectroscopy (SERS), photothermal therapy (PTT), and so on. In this chapter, we start by reviewing the theoretical and experimental approaches in studying the optical properties of the MXenes and then discuss the impactful optical device demonstrations.