Low-power photonic organic artificial synapse inspired by dopamine-facilitated synaptic activity

The ability of the synaptic plasticity in an artificial synapse can offer significant improvement in low-power recognition, and learning capability in a neuromorphic system [1]. Inspired by light-assisted dopamine-facilitated, which achieves rapid learning and adaptation by lowering the threshold of the synaptic plasticity, we fabricate a organolead halide perovskite (OHP)-based photonic synapse in which the synaptic plasticity is modified by both electrical pulses and light illumination. Owing to the accelerated migration of the iodine vacancy inherently existing in the OHP film under light illumination, the OHP synaptic device exhibits light-tunable synaptic functionalities with very low programming inputs (~0.1 V). It is also demonstrated that the threshold of the long-term potentiation decreases and synaptic weight further modulates when light illuminates the device. Notably, under light exposure, the OHP synaptic device achieves rapid pattern recognition with ~81.8% accuracy with a low power consumption (4.82 nW/the initial update for potentiation), which is ~2.6×10³ times lower than when the synaptic weights are updated by only high electrical pulses.
References
[1] Jo, S. H.; Chang, T.; Ebong, I.; Bhadviya, B. B.; Mazumder, P.; Lu, W. Nano Lett. 2010, 10, 1297-1301