MXene-Based Perfect Absorber Design and Refractive Index Sensing Performance

In this study, a MXene-based electromagnetic absorber with a simpledesign at terahertz frequencies is proposed. An absorber that has aMXene layer drilled into with square and circular cavities and thin alu-minum layer as a reflector was examined. With the proper design ofthe structure dimensions, a MXene-based refractive index sensor with adual-band at THz frequency and 99.93% and 97.85% absorption lev-els were obtained. The proposed design achieved 1983 and 1935 Q-factorvalues at frequencies of 0.446 THz and 0.583 THz, respectively. Theproposed sensor with fractional bandwidth of 0.050% and 0.052% hassensitivity values of 686.2 and 557.6 (GHz/RIU). The figure of meritof the proposed sensor is calculated as 3049.8 and 1852.5 (1/RIU) andthe proposed sensor is compared with sensor available in the litera-ture. Since the designed absorber can detect refractive index changes, italso has potential applications in the identification of biological samples.