Plasmonic-Enhanced MoS2 Photodetectors for Polarization-Sensitive Edge Vision

Polarization-sensitive photodetectors have important application value in fields such as polarization imaging, target recognition and edge visual sensing. However, conventional polarization detection schemes suffer from high fabrication costs and the limitation of crystal structures on the polarization response of intrinsic materials, making it difficult to achieve effective polarization detection. In this paper, we propose a MoS2 photodetector enhanced by the Au/polymer nano-elliptical pillar array (AP-NEPA). Experimental results show that AP-NEPA can comprehensively improve the optoelectronic performance of the device in the visible wavelength band. The AP-NEPA-enhanced device achieves a maximum responsivity of 14.4 mA/W and a maximum specific detectivity of 2.16 × 109 Jones. At 640 nm, it achieves a minimum noise-equivalent power of 15 pW/Hz1/2, corresponding to 30.2-, 41-, and 11.3-fold enhancements in photocurrent, responsivity, and detectivity, respectively. The induced anisotropic plasmonic coupling further enables polarization-dependent photoresponse with a polarization ratio of 1.4 at 520 nm. As a proof of concept, the measured polarization-dependent photocurrents are used as convolution weights for offline edge-feature extraction from blurred and noisy images, demonstrating the potential of the device for polarization-assisted image preprocessing.