Refining the Negative Differential Resistance Effect in a TiO_<i>x</i>-Based Memristor

Abstract

The N-type negative difference resistance (NDR) is characterized by the peak/valley voltage (<i>V</i>_p/<i>V</i>_v) and the corresponding current (<i>I</i>_p/<i>I</i>_v). The N-type NDR is observed in the resistive switching (RS) memory device of Ag|TiO₂|F-doped SnO₂ at room temperature. After the TiO₂ film is equipped with a nanoporous array, the ∼1.2 V gap voltage between <i>V</i>_p and <i>V</i>_v is effectively downscaled to ∼0.5 V, and the gap current of ∼7.23 mA between <i>I</i>_p and <i>I</i>_v is improved to ∼30 mA. It demonstrates that a lower power consumption and faster switching time of the NDR can be obtained in the memristor. Compensations and synergies among the nanoscale conduction filaments (OH^-, Ag⁺, and V_o) are responsible for the refining NDR behavior in our devices. This work provides an efficient method to construct a high-performance N-type NDR effect at room temperature and gives a new horizon on the coexistence of this type of NDR effect and RS memory behaviors.