- Invisible radar a boost for defence
- Lighting event part of Sydney’s Vivid
- RF switches for an array of applications
- Is a legal dispute with Apple costing chip maker Qualcomm?
UNIVERSITY of Wollongong physicists have discovered a new method of constructing nanowires for use as semiconductors, which promises enhancements for building advanced electronic and photonic devices.
PhD student Julian Steele says control over the tiny structures is critical in determining their final applications.
“The more control we have over a wider range of materials, the more we extend the palette of functional design options available to engineers,” said Steele.
While silicon is currently the most commonly used element for electronics and semiconductors, researchers are also looking into other elements, such as bismuth.
Bismuth is added to gallium and arsenide, but because it is heavier, it resists entering into the gallium-arsenide crystal, but instead gathers on the surface in small droplets.
“These droplets act as a catalyst for the growth of nanostructures, which in this case turned out to self-assemble in the form of tracks,” Steele explained. “The nanotracks themselves were grown by our collaborators at in the UK and the US, who were actually trying to grow solid thin-film materials.
The University of Wollongong researchers wanted to understand why the nanostructures formed track shapes. Previous theoretical models which described the growth of the structures could not explain the unusual shapes.
The researchers succeeded in coming up with a new type of detailed growth model. They tested the model using simulation, which corroborated with the experiment, yielding insights into the psychical origins of some of the more exotic features observed in these nanotracks.
The research leads to a better understanding of the self-assembly process, where materials aggregate and form structures without external interference or direction.
Self-assembly could be exploited to simplify and speed up the construction of complex materials using nanowires, leading to advanced applications.
This could include new devices such as flat-panel displays thinner than currently available; high-efficiency solar cells that can be integrated onto surfaces such as the exterior of a car; and nanowire batteries that can hold up to 10 times the charge of existing lithium-ion batteries.
Researchers are hoping a better understanding of self assembly could bring nanowire applications out of the lab into the world of manufacturing.
“In the same way that the development of new materials late in the 20th century helped to realise our current tech-age – from smartphones to driverless cars – the next frontier is how to assemble these materials at the nanoscale in order to exploit small-scale physics (quantum mechanics), for enhanced efficiency and function,” Steele said.