Tuning Nanowires Promises Superior LED and Solar Cell Technology


Tuning Nanowires Promises Superior LED and Solar Cell Technology

29 April 2014
 
Tuning a small strain on single nanowires can make them more effective in light-emitting diodes (LEDs) and solar cells, a research team in Norway has discovered.
 
Dheeraj Dasa and Helge Weman from the Department of Electronics & Telecommunications at the Norwegian University of Science And Technology (NTNU) in Trondheim experimented with changes at the atom level in nanowires. The scientists found that gallium arsenide can be tuned to function as efficiently as a single LED or as a photodetector. This is facilitated by the "wurtzite" - a special hexagonal crystal structure which the researchers have grown in the university's molecular beam epitaxy (MBE) lab.
 
This is the latest of a series of major discoveries made at the NTNU. In recent years researchers have been working with a patented invention to grow semiconductor nanowires on graphene and the resulting hybrid material has shown good electric and optical properties. According to Weman, graphene will help make much more effective and flexible electronic products, initially solar cells and white LEDs.
 
With the new ability to manipulate nanowires' crystal structure it is possible to create next-generation solar cells. Besides producing more electric power, they would also be very flexible and lightweight, as nanowires grown on graphene have these properties.
 
CrayoNano, a company established by Weman and his NTNU co-founders Bjørn-Ove Fimland and Dong-Chul Kim, is starting to grow gallium nitride nanowires for use in white LEDs. These new lighting bodies, made in the newly installed MBE machine at NTNU, will have better optical properties than the current technology allows and will also be more flexible, lighter and stronger.