Two-terminal photonic neuromorphic devices with short/long-term plasticity based on interface charge effects

Abstract

Synaptic devices have attracted intense research interests recently due to their potentials in overcoming the Von Neumann bottleneck. The light-stimulated synaptic devices based on three-terminal transistors have advantages of sustainability and gate modulation, however, the simultaneous control of multiterminal is complicated for operation. In this work, a new type of two-terminal photoresponsive and synaptic device is developed with easy fabrication process by utilizing the interfacial charge trapping effect introduced by the dielectric layer. This field-effect two-terminal device (FETD) is derived from the three-terminal transistor structure, and hence maintains the field effect advantages of the traditional transistor synaptic device, but has simplified operation. Moreover, the light employed as the additional input signal enables the reading and writing process to be implemented simultaneously. The synaptic functionalities including short-term plasticity and transition from short-term memory to long-term memory are successfully imitated. The flexible device is further developed for the potential application in wearable electronics. Therefore, this work has enlightened a novel structure, which not only retains the advantages of three-terminal synaptic devices with simple operation but also realizes the synchronization of information transfer and learning process by introducing light as input signals. • A two-terminal photoresponsive and synaptic device is developed, with the simple operation and advantages of transistors. • Synaptic functions including short-term plasticity and transition from short-term to long-term memory are imitated. • By using PET-ITO as substrate, the device with low operation voltage below 1.5 V shows good flexibility and stability.