Neuromorphic computational artificial synapses based on a BTO/STO memristor under Au ion implantation

The successful fabrication of artificial synapses is essential for developing highly integrated neuromorphic devices. Notably, defects in the memristor's functional oxide film crucially determine the stability of artificial synapses and the underlying components of neuromorphic computation. In this study, a memristor composed of BaTiO₃ (BTO) and SrTiO₃ (STO) films with Au ion implantation exhibited improved stability in the I–V cycle as well as enhanced multilevel storage performance. Here, the ON/OFF ratio of the device was increased from 600 to 10⁴ after ion implantation. Moreover, the 10¹² cm⁻² device successfully realizes basic biological synaptic functions, including long-term potentiation/depression (LTP/LTD), paired-pulse facilitation (PPF) and spiking time-dependent plasticity (STDP). The experimental findings yield a novel investigative concept for subsequent evolution of artificial synaptic devices.