Co-existence of bipolar nonvolatile and volatile resistive switching based on WO3 nanowire for applications in neuromorphic computing and selective memory

A two-terminal memristor can be used for information memory and logic operation as well as serving as an artificial synapse for neuromorphic computing. Selective memory with some enjoyable information to be remembered and other to be screened out can be emulated by an artificial synapse. In this work, a memristor based on a single WO3 nanowire can be constructed, which demonstrates the co-existence of bipolar nonvolatile and volatile resistive switching (RS) behaviors that can be tuned by the amplitude of the operation voltage. For small operation voltages (2 V), the device demonstrates nonvolatile analog RS, which can be utilized as an artificial synapse with long- and short-term plasticity. The learning–forgetting experience of human can be emulated based on the artificial synapse. Moreover, the artificial synapse can be used for image recognition with the recognition accuracy up to 94% for small hand-written image. On the other hand, volatile RS can be observed with large operation voltages (6 V). Furthermore, based on the diverse nonvolatile and volatile RS behaviors, selective memory can be emulated. Our fabricated memristor can be used as an artificial synapse to achieve image recognition and to emulate selective memory, which paves a way to construct smart neuromorphic systems facing complex information.