Novel approach to advanced electronics, data storage with ferroelectricity

From left, Prof Jan Seidel (UNSW), Dr Dawei Zhang (UNSW), and Dr Pankaj Sharma (Flinders University)

Published first at Flinders University

Latest research from Flinders University and UNSW Sydney, published in the American Chemical Society ACS Nano journal, explores switchable polarization in a new class of silicon compatible metal oxides and paves the way for the development of advanced devices including high-density data storage, ultra low energy electronics, and flexible energy harvesting and wearable devices.

The study provides the first observation of nanoscale intrinsic ferroelectricity in magnesium-substituted zinc oxide thin films, i.e. metal oxide thin films with simple wurtzite crystal structures. Ferroelectrics akin to magnets exhibit a corresponding electrical property known as permanent electric polarisation, which stems from electric dipoles featuring equal but oppositely charged ends or poles. The polarization can be repeatedly altered between two or more equivalent states or directions when subjected to an external electric field and, thus the switchable polar materials are under active consideration for numerous technological applications including fast nano-electronic computer memory and low-energy electronic devices.

“The research findings offer significant insights into the switchable polarisation in a new class of much simpler silicon-compatible metal oxides with wurtzite crystal structures and lay a foundation for the development of advanced devices,” says corresponding and last author Dr Pankaj Sharma, Lecturer at Flinders University.

Left – Polarisation switching with applied voltage in the range of a few Volts in Mg-ZnO thin films. Right – Read electrical current for Mg-ZnO nanocrystals with different polarization directions. The electrical current changes by a factor of ~100 for nanocrystals with opposite polarization direction (within and outside the enclosed boundaries), and shows the potential towards nano-electronic digital data storage. Image Courtesy – Flinders University.

“The demonstrated material system offers very real and important implications for new technology and translatable research,” says corresponding author UNSW Sydney Professor Jan Seidel.

Historically, this technologically important property has been found to exist in complex perovskite oxides that incorporate a range of transition metal cations leading to diverse physical phenomena such as multiferroicity, magnetism, or even superconductivity.

“But, integrating these complex oxides into the semiconductor manufacturing processes has been a significant challenge due to stringent processing requirements related, for instance, to thermal budget and precise control of multiple constituent elements. The present study therefore provides a potential solution” – notes first author Haoze Zhang (UNSW, Sydney).

The article, ‘Robust Switchable Polarization and Coupled Electronic Characteristics of Magnesium-Doped Zinc Oxide’ (2023) has been published in ACS Nano 2023, 17, 17148–17157, DOI: 10.1021/acsnano.3c04937

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Errol HuntNews, Novel Materials, Topological Dissipationless, Uncategorized, UNSW