Deep ultraviolet optical limiting materials: 2D Ti₃C₂ and Ti₃AlC₂ nanosheets

MXenes, a family of two-dimensional nanomaterials that have emerged in recent years, have attracted much attention in the field of optoelectronics due to their unique physicochemical properties and abundant elemental composition. Nevertheless, research studies on the broadband nonlinear optical properties of MXenes are rarely reported, especially in the deep ultraviolet region. Herein, we investigated the broadband nonlinear absorption properties (deep ultraviolet to near-infrared waveband) of Ti3C2 and Ti3AlC2 nanosheets by picosecond Z-scan. To the best of our knowledge, this is the first time that two-dimensional materials exhibit efficient optical limiting properties at deep ultraviolet wavelengths as short as 266 nm. Our results reveal the great potential of Ti3C2 and Ti3AlC2 nanosheets for laser protection, optical sensors, and device protection in the deep ultraviolet band, which are anticipated to be beneficial for the further design of MXene-based optical limiting devices.