Improved on/off ratio in interface-type memristors with an ion irradiation-induced large Schottky barrier for neuromorphic computing

Abstract

As a cutting-edge research direction in neuromorphic devices, interface-type (IT) memristors leverage interfacial engineering for resistive switching owing to the filament-free switching, low power dissipation, and high scalability. However, the trap states governing the interfacial Schottky barrier often exhibit a discrete and stochastic distribution. This study utilizes Xe ion irradiation with a fluence of 5 × 10¹⁰, 1 × 10¹¹, 5 × 10¹¹, 1 × 10¹² and 3 × 10¹² cm⁻² to introduce defects near the surface of Nb:SrTiO₃ (NSTO), thereby controlling the interface Schottky barrier. The device with the fluence of 1 × 10¹² cm⁻² maintains good stability and excellent cyclic endurance characteristics, and increases the on/off ratio by an order of magnitude (from 10⁵ to 10⁶). Meanwhile, it can well simulate the synaptic function and in the neurological system, the recognition accuracy of images reaches 94.4%. These results indicate that ion irradiation can improve the resistance of IT memristors and be used in artificial synapses to establish the next generation of neural morphology calculation.