Scientists discover new structure that could contribute to bioterror protection

Researchers with the University of Cincinnati recently discovered a new structure in a semiconductor nanowire with unique properties that could lead to more effective air quality sensors and better security against biological weapons.

Physics professors Howard Jackson and Leigh Smith and their colleagues recently published a paper on the research titled "Optical, Structural and Numerical Investigations of GaAs/AlGaAs Core-Multishell Nanowire Quantum Well Tubes" in Nano Letters. The new structure could increase the number of applications of semiconductors in multiple technologies such as biosecurity.

"This kind of structure in the gallium arsenide/aluminum gallium arsenide system had not been achieved before," Jackson said. "It's new in terms of where you find the electrons and holes, and spatially it's a new structure."

Semiconductors are used in TVs, computers, cellphones and many other types of modern technology. The scientists used a thin shell called a quantum well tube and grew it to about four nanometers thick around the nanowire core. They found the electrons within the nanowire were distributed in an odd way in relation to the hexagonal tube's facets. The researchers discovered a high concentration of ground state electrons and holes after looking at the corners of the tube's facets.

"Having the faceting really matters," Jackson said. "It changes the ballgame. 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."

Semiconductors are made from the crystalline form of elements with scientifically beneficial properties of electrical conductivity. Semiconductor nanowires are 1,000 times thinner than a human hair.