Current-Controlled Negative Differential Resistance due to Joule Heating in TiO2

TL;DR

This paper demonstrates that Joule heating induces current-controlled negative differential resistance in TiO2, modeled analytically through polaronic transport and thermal effects, elucidating the soft breakdown and switching behavior in memristors.

Contribution

An analytical model linking Joule heating and polaronic conduction explains CC-NDR in TiO2 and its role in memristor switching phenomena.

Findings

Joule heating causes CC-NDR in TiO2.

The V(I) curve shape indicates polaronic conduction nature.

Model fits experimental data of TiO2 switching behavior.

Abstract

We show that Joule heating causes current-controlled negative differential resistance (CC-NDR) in TiO2 by constructing an analytical model of the voltage-current V(I) characteristic based on polaronic transport for Ohm's Law and Newton's Law of Cooling, and fitting this model to experimental data. This threshold switching is the 'soft breakdown' observed during electroforming of TiO2 and other transition-metal-oxide based memristors, as well as a precursor to 'ON' or 'SET' switching of unipolar memristors from their high to their low resistance states. The shape of the V(I) curve is a sensitive indicator of the nature of the polaronic conduction.