Optically Stimulated\nArtificial Synapse with Ferroelectric\nAssistance for a Neuromorphic Visual System

To address the challenges faced by a traditional computing\nsystem\nwith von Neumann architecture, various artificial synapses and neurons\nhave been developed. In this work, a two-terminal device was developed\nusing an organic p-type semiconductor copper phthalocyanine (CuPc)\nand a molecular ferroelectric diisopropylammonium bromide (DIPAB).\nThe incorporation of the ferroelectric layer DIPAB not only introduces\nan energy barrier for the migration of photogenerated carriers to\nenhance the device’s synaptic performance but also enables\nthe modulation of the device response to the light pulses by changing\nthe polarization state of DIPAB. The device successfully mimics the\nbiological synaptic functions including paired-pulse facilitation\n(PFF), spike-rate-dependent plasticity (SRDP), and spike-number-dependent\nplasticity (SNDP). The device is employed to recognize MNIST handwritten\ndigits, achieving a recognition rate of over 75% for MNIST handwritten\ndigits even with 50% noise interference. These results suggest the\ndevice’s potential for neuromorphic computing.