Organic molecular crystal-based photosynaptic devices for an artificial visual-perception system

Recreating the visual-perception properties using organic electronic devices is highly desired for visual prosthetics and artificial intelligence. Although the integration of organic light-sensing components with synaptic devices can realize the recognition and memory functions for perceived images, complicated problems in device integration for practical applications are generally encountered. Here we demonstrate a new type of organic photosynaptic device based on organic molecular crystals, which can provide optical-sensing and synaptic functions together in one device by means of a unique photon-induced charge transfer effect. This device successfully emulates the working principles of human visual perception in terms of short-term plasticity, long-term potentiation, and spike-timing-dependent plasticity. Moreover, a proof-of-concept artificial image-perception system is demonstrated by integrating the photosynapses on a flexible substrate. The new devices using organic semiconductors may open up innovative application areas, such as artificially intelligent electronic and perception systems, and facilitate the integration of such devices into next-generation flexible and stretchable electronics.