Electrochemical aspects of semiconductors no longer ‘flawed’

New research on the workings of currents in semiconductor electrodes has been published in prestigious journal Nature Communications.

A research team that includes ARC Centre of Excellence for Electromaterials Science (ACES) investigators has developed an experimental platform and new theoretical model that opens up debate about fundamental understanding of how currents in semiconductor electrodes fully work.

The research by ACES affiliate investigator Dr Simone Ciampi’s team from Curtin University, Professor Joaquin Gonzalez from Universidad de Murcia, ACES Chief Investigator Professor Michelle Coote at Australian National University (ANU), ACES researchers Mr Long Zhang and Prof Gordon Wallace from the University of Wollongong along with collaborators from  University of New South Wales and the Australian Nuclear Science and Technology Organisation (ANSTO) – titled Reproducible flaws unveil electrostatic aspects of semiconductor electrochemistry – has just been published in Nature Communications (December 2017).

The team have been able to reproduce and explain the often puzzling behaviour of electrons that enter or leave semiconductor materials commonly used in the electronics industry.

The research highlights the interplay between dynamic charges and semiconductors by developing new models (developed by Professor Joaquin Gonzalez from Universidad de Murcia) and experiments to explain controversial aspects of charge movement across silicon surfaces.

Dr Ciampi said the team’s research outcomes could potentially lead to more reliable and more predicable silicon devices as well as removing a significant barrier for the academic field of molecular electronics to enter in the electronics industry.

“Silicon has been a very successful semi-conductor material, and it is widely used in every day electronic devices, with some experts even dubbing this the ‘silicon era’,” Dr Ciampi said.

“You would be hard-pressed to find a modern electronic device that is not based on the electrical response of a silicon semiconductor component.

“Interestingly, a few significant aspects of how charges move across this interface still remain unexplained, and our research created new theoretical and experimental models that explained how the balance between static and dynamic charges works, why it cannot be neglected and how to account for it.”

The researchers observed unusual current flow patterns as a function of applied electrical potential. They attempted to recreate that same irregular pattern, to see if it was a flaw, or indeed a normal and predictable part of the semiconductor’s electrostatic chemical reactivity.

“Commonly when a scientist or engineer experienced an irregular shape in the electrode process, they would dismiss it as a type of ‘flaw’. These ‘flaws’ were some of the remaining unexplained aspects in the silicon semiconductor components,” Dr Ciampi said.

During investigations the research team successfully reproduced these irregular patterns, concluding they were not flaws at all, but instead part of the routine electrostatic interactions.

Using this data, they then created a new theoretical model that addressed the non-ideal current flow patterns as a function of the applied potential, explaining their presence.

“We hope that this new model will allow for the development of more reliable and more predictable silicon semiconductors in the electronics industry.”

Prof Wallace said the findings highlighted the importance of collaboration between researchers.

“This research can only be achieved and progressed by interdisciplinary and collaborative research teams, such as those that can be quickly assembled under the ACES umbrella,” Prof Wallace said.

The full research paper Reproducible flaws unveil electrostatic aspects of semiconductor electrochemistry can be found online here.