A research team at Swansea University’s Centre for NanoHealth has released a paper highlighting its research into electrical conductivity at the atomic scale in zinc oxide nanowires.
The findings, published in the Nano Letters journal, demonstrate the limits of electrical conductivity at small scales, particularly at the interface of the metal/semiconductor boundary. This knowledge will help to optimize the flow of electricity in nanowires in a predictable and stable manner. This research could prove incredibly useful as it has applications in nanomedicine, which relies heavily on nanomaterials.
The research has demonstrated that the geometry of the nanowires themselves has an effect on conductivity due to atomic changes to the metal catalyst particle edge, which can entirely alter electrical conduction. This also demonstrates the first physical evidence of a phenomenon in electrical contacts known as “barrier inhomogeneity.” Until now, the stability of the interfaces over lengthy time periods and the electrical limits of the ohmic or Schottky function have not been studied.
“The experiments had a simple premise but were challenging to optimize and allow atomic-scale imaging of the interfaces. However, it was essential to this study and will allow many more materials to be investigated in a similar way,” said Dr. Alex Lord, research fellow at the Centre for NanoHealth. “This research now gives us an understanding of these new effects and will allow engineers in the future to produce electrical contacts to these nanomaterials reliably, which is essential for the materials to be used in the technologies of tomorrow.”
The research is a collaborative effort between Lord and Prof. Quentin Ramasse of the SuperSTEM Laboratory, Science and Facilities Technology Council and Dr. Frances Ross of the IBM Thomas J. Watson Research Center in the United States. Between the researchers, they were able to interact with the nanostructures physically and measure how atomic changes in the materials affected the electrical performance, using specialized imaging equipment located at the Centre for NanoHealth.
“This research shows the importance of global collaboration, particularly in allowing unique instrumentation to be used to obtain fundamental results that allow nanoscience to deliver the next generation of technologies,” said Ross.
The research paper, entitled “Stability of Schottky and Ohmic Au Nanocatalysts to ZnO Nanowires,” can be found in the Nano Letters journal.