A high-performance polarization-enhanced black phosphorus photodetector by a nonlocal metasurface

Black phosphorus (BP) is a promising two-dimensional (2D) material with extraordinary optical anisotropic properties in the near-infrared region (NIR). It is widely exploited in NIR photodetecting, NIR imaging, and NIR polarization detecting. Despite its superior anisotropy, the polarized response is still limited to several layers. We present a polarization-enhanced black phosphorus photodetector based on a nonlocal metasurface. Benefiting from enhanced light-BP interaction, the device responsivity is improved by 7 times over that of non-enhancement. At zero bias, our device has a responsivity of 9.13 mA/W with 1514 nm incidence. Our photodetector performs an ability to enhance the selective polarization photoresponse of BP armchair direction or zigzag directions by changing the BP placement. Enhanced by polarization sensitive resonance, the cross polarization response ratio (PR) increases from ∼2.3 to ∼13.1. Our results indicate that the device has potential for NIR polarization imaging and polarization multiplexing detecting areas.