Fig. 1. Schematic of the impedance matching model. (a) THz transmission through pure Si substrate; (b) THz transmission through Si/MXene film

Fig. 2. SEM morphology of MXene film with different stacking layers. (a) 1 layer; (b) 2 layers; (c) 4 layers; (d) 8 layers

Fig. 3. Schematic of the relationship between THz wave reflection signal and MXene film thickness under different incident angles. (a) 30°; (b) 40°; (c) 50°; (d) 55°

Fig. 4. Schematic of the normalized THz reflected signals as a function of MXene with different stacking film layers under different angles. (a) 30°; (b) 40°; (c) 50°; (d) 55°

Fig. 5. THz reflection imaging result at the Air/ Si interface changing with MXene with different stacking film layers at Si substrate. (a) 1 layer; (b) 3 layers; (c) 6 layers; (d) 8 layers

Fig. 6. THz reflection imaging result at the Si/MXene/Air interface changing with MXene with different stacking film layers. (a) 1 layer; (b) 3 layers; (c) 4 layers; (d) 5 layers; (e) 6 layers; (f) 8 layers

Fig. 7. THz transmission intensity of the samples changing with MXene with different stacking film layers. (a) Time-domain spectra of THz-wave transmission; (b) normalized THz transmission