Charge transport in amorphous Hf$_{0.5}$Zr$_{0.5}$O$_2$

TL;DR

This paper investigates charge transport in amorphous Hf$_{0.5}$Zr$_{0.5}$O$_2$, demonstrating phonon-assisted tunneling between traps and identifying trap energies through experimental and theoretical analysis.

Contribution

It provides the first combined experimental and theoretical analysis of charge transport mechanisms in amorphous Hf$_{0.5}$Zr$_{0.5}$O$_2$, highlighting phonon-assisted tunneling and trap energies.

Findings

Thermal trap energy of 1.25 eV identified.

Optical trap energy of 2.5 eV identified.

Oxygen vacancies hypothesized as charge transport centers.

Abstract

In this study, we demonstrated experimentally and theoretically that the charge transport mechanism in amorphous Hf$_{0.5}$Zr$_{0.5}$O$_2$ is phonon-assisted tunneling between traps like in HfO$_2$ and ZrO$_2$. The thermal trap energy of 1.25 eV and optical trap energy of 2.5 eV in Hf$_{0.5}$Zr$_{0.5}$O$_2$ were determined based on comparison of experimental data on transport with different theories of charge transfer in dielectrics. A hypothesis that oxygen vacancies are responsible for the charge transport in Hf$_{0.5}$Zr$_{0.5}$O$_2$ was discussed.