Ultrabroadband UV-IR Self-Power Full-Stokes Polarization Photodetection and Imaging Based on the CsPbBr₂I/Si Heterojunction

Silicon has become a leading material in photoelectric detection, owing to its distinct advantages in both response speed and photoelectric conversion efficiency. However, due to the lack of intrinsic polarization selectivity, silicon still faces major challenges in achieving polarization detection in the broadband ultraviolet (UV) to infrared (IR) range. In this paper, we have successfully developed an ultrabroadband UV-IR polarization photodetector with a Ag/CsPbBr₂I/Si/Ag vertical structure based on the CsPbBr₂I and N-type pyramid-silicon composite structure, which is designed to achieve full Stokes polarization detection. The device exhibits excellent broadband polarization response in the ultraviolet to infrared band (405-1319 nm), especially at 1064 nm, showing an anisotropy ratio of up to 72.7. By optimizing the anisotropic optical response of CsPbBr₂I and nanoscale pyramid silicon structures, the device achieves a fast response time of 4 μs under 1064 nm illumination at a zero bias voltage. The experimental results show that the detector has a stable and fast optical switching response and excellent polarization sensitivity in the broadband range. The maximum response reaches 270 mA/W under 1064 nm illumination at zero bias voltage, the normalized detection rate is 2.6 × 10¹³ Jones, and the noise equivalent power is 44 pW/Hz^1/2. Through in-depth discussions, the photoelectric response mechanism at 1319 nm is attributed to the PTE effect and the heterojunction effect. In addition, the full Stokes parameter verifies the effectiveness of the device in polarization state characterization, and the single-point pixel imaging experiment further confirms its application potential in broadband polarization imaging. This study proposes a novel approach for advancing the next generation of the on-chip polarization imaging system and shows an important application prospect in the fields of safety detection, high-resolution medical imaging, and medico-industrial intersection.