Flexible Optoelectronic Synapses Based on Conjugated Polymer Blends for Ultra Broadband Spectrum Light Perception
Longlong Jiang, Lu Yang, Yiming Yuan, Qingshan Zhu, Wenjie Wu, Xiaohong Wang, Wentao Xu, Longzhen Qiu
Abstract
We demonstrate a flexible optoelectronic synaptic device that uses a donor–acceptor conjugated polymer with excellent electrical properties and a highly optically active block copolymer to form a heterojunction as the active layer, enabling ultrabroad-spectrum perception from deep ultraviolet (DUV), to visible (vis), and to near-infrared (NIR) for the first time. Essential synaptic behaviors have been successfully simulated, such as learning experience behavior simulation, international Morse code communication, and high-pass filtering. The synaptic device shows stable synaptic properties when bent at different radii of curvature and at different numbers of bending cycles. When the device is extremely deformed under a radius of curvature of 4 mm, the postsynaptic current is still maintained above 84%. Moreover, an artificial reflex arc was constructed using the flexible optoelectronic synapse as a key information processing unit. Recognition of digits was achieved by constructing an artificial neural network under DUV light stimulation, achieving the highest recognition rate so far, up to 94%. This work demonstrates a methodology to prepare flexible synaptic devices with tunable synaptic plasticity and broad-spectrum perception that is potentially applicable to building flexible neuromorphic electronics.