Recent Progress in Organic-Based Photonic Synapses

Abstract

Organic photonic synapses are promising candidates for optoelectronic neuromorphic electronic components owing to their advantages from both material and signal perspectives. Organic materials have advantages such as low cost, tunable properties according to the molecular design, mechanical flexibility, and biocompatibility. In addition, using light as an input signal affords advantages such as ultrafast signal transmission speed, wide bandwidth, and wireless communication. Thus, different types of organic photonic synapses have been researched using various mechanisms and new materials. In this review, we first introduce the biological synaptic properties imitated by photonic synapses. Next, the operating mechanism and materials used are discussed by categorizing the device structures into two-terminal and three-terminal devices. To verify the applicability of organic photonic synapses in the real world, we present various applications such as pattern recognition, smart windows, and Pavlov’s dog experiment, which have been demonstrated in previous studies. Finally, we discuss the remaining challenges and provide directions for further research on organic photonic synapses.