Fig. 1. (a) Schematic model of the device structure; (b) Optical micrograph of the device (with the simulated electric field distribution of a butterfly antenna optimized by finite-difference time-domain method in the top right corner); (c) Height distribution map of the graphene-MnBi₂Te₄ heterostructure measured by AFM; (d) Raman spectrum of graphene-MnBi₂Te₄

Fig. 2. (a) I-V testing curve of the device; (b) Dependence of device photocurrent on bias voltage under 0.04 THz and 0.12 THz radiation; (c) Response time of the device under 0.12 THz radiation; (d) Relation between photocurrent and incident power at 0.12 THz radiation for the device

Fig. 3. Device responsivity dependence on bias voltage under 0.04 THz and 0.12 THz radiation

Fig. 4. (a) Schematic of the PTE effect mechanism; (b) Band diagram of graphene-MnBi₂Te₄ heterostructure

Fig. 5. (a) Schematic diagram of the terahertz imaging system setup; (b) Imaged object; (c) Imaging result