Natural polyelectrolyte-based ultraflexible photoelectric synaptic transistors for hemispherical high-sensitive neuromorphic imaging system

Abstract

Outstanding features of the human retina are its concave hemispherical geometry, high-sensitive image acquisition, and neuromorphic visual processing, which not only simplifies the optical complexity for the eye but also enhances imaging quality for the visual perception. However, the development of a high-performance bioinspired imaging system with these features is extremely challenging because of the restriction of its composing materials, device structures, and conventional imaging modules. Here, we present a novel hemispherical high-sensitive neuromorphic imaging system that leverages a natural acidic polyelectrolyte as dielectric layer in the photoelectric synaptic transistors. The devices have an extraordinary photosensitivity (~104) under a dim light condition (56 μW/cm2) and the light-tunable neuromorphic characteristics, as well as a substrate-free and ultrathin (~475 nm) structure. These advantages enable our system to perform high-quality imaging like the human retina and highly simulate various functions of the human visual system, such as image enhancement and erasure, and visual preprocessing.