A Room‐Temperature Terahertz Photodetector Imaging with High Stability and Polarization‐Sensitive Based on Perovskite/Metasurface

Terahertz (THz) polarization detection facilitates the capture of multidimensional data, including intensity, phase, and polarization state, with broad applicability in high‐resolution imaging, communication, and remote sensing. However, conventional semiconductor materials are limited by energy band limitations, rendering them unsuitable for THz detection. Overcoming this challenge, the realization of high‐stability, room‐temperature polarization‐sensitive THz photodetectors (PDs) leveraging the thermoelectric effect of Cs 0.05 (FA 0.85 MA 0.15 ) 0.95 Pb(I 0.85 Br 0.15 ) 3 (CsFAMA)/metasurfaces is presented. Two different structures of (T‐shaped and I‐shaped) THz PDs are constructed. The incorporation of perovskite/metasurfaces forms enhanced local field thermoelectric effect and polarization response. Owning to THz surface plasmon polariton (SPP) resonance effect and more boundary effect, the I‐shaped PDs exhibit superior performance, achieving a response of up to 94 V/W, with a response time of 138 µs, a low noise‐equivalent power of 5.03 pW/Hz 1/2 and an anisotropy ratio of 1.38 under 0.1THz laser irradiation. Furthermore, the PD's stability is verified with the anisotropy ratio decreased by only 2% and polarization imaging results after 240 days of storage in air condition. This research introduces a method for achieving high‐performance, stable THz polarization detection technology, with significant potential for advancements in materials science, communication technology, and medical imaging.