Microcavity-Enhanced Polarization Photodetection in Antimony Selenide Nanotube-Based Near-Infrared Photodetectors

This study presents the polarization photodetection enhancement in Sb₂Se₃ nanotube (NT)-based near-infrared (NIR) photodetectors through simulation-based and experimental investigations. High-quality single-crystal Sb₂Se₃ NTs are grown via chemical vapor deposition and characterized by using multiple techniques. The optical simulation reveals a remarkable difference in the light absorption ratio (specifically, absorption along the NT/nanowire (NW) against absorption perpendicular to the NT/NW) between Sb₂Se₃ NT and NW of the same size in the NIR region. The complementary photodetection experiments present that the fabricated Sb₂Se₃ NT photodetector demonstrates enhanced polarization photodetection in the NIR range, as indicated by a significantly increased dichroic ratio (3.03 at 850 nm) compared to that of similar-sized NW counterpart (1.81 at 850 nm). Additionally, the Sb₂Se₃ NT photodetector exhibits exceptional performance, with a high responsivity of 4.18 A W^-1 and specific detectivity of 8.94 × 10¹⁰ Jones under 830 nm light illumination. This study provides a comprehensive understanding of the microcavity resonance effect and its role in polarization photodetection enhancement, highlighting the potential of self-assembled Sb₂Se₃ NTs in high-performance near-infrared polarized photodetection and other relevant applications.