Avian eye-inspired tetrachromatic-bidirectional synaptic transistor for multi-spectral recognition

The spectral recognition is key for efficient machine vision to obtain high imaging quality of color target objects. However, the bidirectional response within a single band of vision sensors is still challenging to in-site recognize color target objects from a multi-spectral context. Here, inspired by avian eyes, we propose a tetrachromatic-bidirectional synaptic transistor based on WOx/WSe2 heterojunctions with a ultraviolet (UV)-photoactive floating gate of CdS and realize the bio-avian vision with enhanced image and improved recognition under a multi-spectral background. The positive-synaptic responses are exhibited within the visible wavelength band while the negative response is for the UV wavelength band. Moreover, the bionic-kestrel vision behaviors are exhibited, such as the in-site enhanced color object images and the improved recognition accuracy from 58% to 93.1% due to the contribution of UV negative response. This work provides an effective neuromorphic vision to recognize the feature signatures from the multi-spectral contexts.