Au NPs Intercalated MoTe₂/ReS₂ Heterojunction Photovoltaic Detectors for Image Processing and Motion Recognition

Motion recognition and image preprocessing are critical for artificial vision systems, but there remains a need for more efficient and energy-saving devices with versatile image processing capabilities. Herein, we developed highly efficient photovoltaic detectors with bidirectional photocurrent and polarization-sensitive characteristics by sandwiching gold nanoparticles (Au NPs) between MoTe₂ and ReS₂, enabling two photoelectric units to operate collaboratively. The Au NPs induce localized surface plasmon resonance (LSPR) and hot electron injection, modulating the interface electronic structure, enhancing the light absorption efficiency, and extending the spectral response range to 1550 nm, surpassing the bandgap limitations of MoTe₂ and ReS₂. The responsivity and detectivity reach up to 8.35 A W⁻¹ and 9.6 × 10¹¹ Jones under 808 nm, respectively, which are about two orders of magnitude improvement over the pristine MoTe₂/ReS₂ device. The polarization ratio (PR) also increases from 4.7 to 9.1, which enables multi-task image processing applications. Leveraging the bidirectional photocurrent and polarization photo-response, the convolution processing is further combined with the device for realizing motion recognition and image processing tasks, including sharpening, edge extraction, and noise filtering. This work opens a new avenue for the development of Au NPs engineered photodetectors for image processing and motion recognition applications.