New research led by University of Cincinnati physics professors Howard Jackson and Leigh Smith could contribute to better ways of harnessing solar energy, more effective air quality sensors or even stronger security measures against biological weapons such as anthrax. And it all starts with something that’s 1,000 times thinner than the typical human hair – a semiconductor nanowire.
These little structures could have a big effect on a variety of technologies. Semiconductors are at the center of modern electronics. Computers, TVs and cellphones have them. They’re made from the crystalline form of elements that have scientifically beneficial electrical conductivity properties. Many semiconductors are made of silicon, but in this case they are made of gallium arsenide. And while widespread use of these thin nanowires in new devices might still be around the corner, the key to making that outcome a reality in the coming years is what’s in the corner.
By using a thin shell called a quantum well tube and growing it – to about 4 nanometers thick – around the nanowire core, the researchers found electrons within the nanowire were distributed in an unusual way in relation to the facets of the hexagonal tube. A close look at the corners of the tube’s facets revealed something unexpected – a high concentration of ground state electrons and holes.
“Having the faceting really matters. It changes the ballgame,” one of the researchers says. “Adjusting the quantum well tube width allows you to control the energy – which would have been expected – but in addition we have found that there’s a highly localized ground state at the corners which then can give rise to true quantum nanowires.”
The nanowires the team uses for its research are grown at the Australian National University in Canberra, Australia – one partner in this project that extends to disparate parts of the globe.
The team’s discovery opens a new door to further study of the fundamental physics of semiconductor nanowires. As for leading to advances in technology such as photovoltaic cells, Jackson says it’s too soon to tell because quantum nanowires are just now being explored. But in a world where hundreds of dollars’ worth of technology is packed into a 5-by-2.5 inch iPhone, it’s not hard to see how small but powerful science comes at a premium.
This story is reprinted from material from University of Cincinnati, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.