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

Abstract

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_0.85MA_0.15)_0.95Pb(I_0.85Br_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.