Three-Terminal VO2-Based Device with Internal Read-Write Switching

Memristive devices based on correlated Mott materials have great potential for memory applications, and specifically neuromorphic computations, due to their simple structure, miniaturization capabilities, power efficiency, and operation speeds. For these reasons, many efforts are made to design improved synaptic devices based on Mott materials. This work demonstrates a nonvolatile memristive three-terminal transistor based on the correlated oxide VO2, which has a (Mott) metal-insulator transition near room temperature. An ultrathin VO2 layer is incorporated in a metal-oxide-semiconductor field-effect geometry using alumina as the gate dielectric. A field effect is demonstrated to modify the channel's resistance in a nonvolatile and reversible fashion. However, only when the gate voltage is applied at the metallic state of the VO2 does the resistance of the insulating state change. Thus, the metallic and insulating states, reached via heating and cooling, act as a write-read switch. Field-induced oxygen motion is the probable mechanism, and a model based on oxygen motion at the VO2/Al2O3 interface reproduces the observed results well. This study provides a proof of principle for the development of high-performance electronic synaptic transistors utilizing Mott materials, where the fully solid-state composition simplifies fabrication and enables integration with silicon-based architectures for future applications.