Spike-dependent plasticity modulation in TiO2-based synaptic device

The realization of highly efficient neuromorphic computing necessitates the development of artificial synaptic devices. This article reports a titanium dioxide (TiO2)-based transparent artificial synaptic device that exhibits almost all functionalities of a biological synapse. The fabricated device exhibits potentiation and depression at very low voltage amplitude (500 mV) input stimuli. The plasticity of the artificial synapse is also studied by varying the number of input stimuli and interval between the pulses (spike-rate-dependent plasticity—SRDP). The transition from short-term plasticity (STP) to long-term potentiation (LTP) is observed for a higher number of input stimuli and shorter interval between pulses. The device possesses excellent paired-pulse facilitation (PPF) with varying width, interval, and amplitude of the input stimuli. The spike-timing-dependent plasticity (STDP), one of the essential characteristics of a biological synapse, is also demonstrated.