Interfacial dead layer effects on current-voltage characteristics in asymmetric ferroelectric tunnel junctions

TL;DR

This paper models how interfacial dead layers affect the electrical behavior of asymmetric ferroelectric tunnel junctions, revealing shifts in polarization loops and current-voltage characteristics due to interface asymmetry.

Contribution

It introduces a self-consistent simulation combining Thomas-Fermi and Landau-Devonshire theories to analyze interfacial effects in ferroelectric tunnel junctions.

Findings

Shifted P-E loops due to interface asymmetry

Unequal coercive fields in positive and negative directions

Dependence of tunneling current on interfacial polarization magnitude

Abstract

Current-voltage characteristics and $P-E$ loops are simulated in SrRuO$_{3}$/BaTiO$_{3}$/Pt tunneling junctions with interfacial dead layer. The unswitchable interfacial polarization is coupled with the screen charge and the barrier polarization self-consistently within the Thomas-Fermi model and the Landau-Devonshire theory. The shift of P-E loop from the center position and the unequal values of the positive coercive field and the negative coercive field are found, which are induced by the asymmetricity of interface dipoles. A complete J-V curve of the junction is shown for different barrier thickness, and the effect of the magnitude of interfacial polarization on the tunneling current is also investigated.