Realization of Self‐Rectifying and Self‐Powered Resistive Random‐Access Memory Memristor Using [001]‐Oriented NaNbO₃ Film Deposited on Sr₂Nb₃O₁₀ Nanosheet at Low Temperatures

Abstract

[001]‐oriented NaNbO3 films are deposited on Sr2Nb3O10/TiN/SiO2/Si substrates at 300 °C. The Sr2Nb3O10 nanosheets are used as a template to form crystalline NaNbO3 films at low temperature. The NaNbO3 films deposited on one Sr2Nb3O10 monolayer exhibit a bipolar switching curve due to the construction and destruction of oxygen vacancy filaments. Because the Sr2Nb3O10 monolayer does not act as an insulating layer, the film does not exhibit self‐rectifying properties. Self‐rectifying properties are observed in the NaNbO3 memristor, which forms on two Sr2Nb3O10 monolayers that act as tunnel barriers in the memristor. The memristor exhibits extensive rectification and on/off ratios of 48 and 15.7, respectively. Tunneling is the current conduction mechanism of the device in the low‐resistance state, and Schottky emission and tunneling are responsible for the conduction mechanism in the high‐resistance state at low and high voltages, respectively. The piezoelectric nanogenerator produced using the [001]‐oriented NaNbO3 film generates high voltage (1.8 V) and power (3.2 μW). Furthermore, endurance of the resistive random‐access memory and nonlinear transmission characteristics of the biological synapse are accomplished in the NaNbO3 memristor powered by the NaNbO3 nanogenerator. Therefore, the [001]‐oriented crystalline NaNbO3 film formed at 300 °C may be utilized for self‐rectifying and self‐powered artificial synapses.