One nanothread is enough

A single zinc oxide nanothread laid over a pencil drawing is enough to create a sensitive UV sensor. In his doctoral thesis, Kamran ul-Hasan researched the combination of zinc oxide and graphene.

The little UV sensor attracted so much attention when it was published in Applied Physics Letters that resulted in the “Research Highlights” section of the prestigious journal Nature.

Ul-Hasan drew a few small shapes on some paper with a pencil and then laid a zinc oxide nanothread over them. There was contact between them, and when UV light fell on the connection, a fully measurable load arose. Thus a small, quick, inexpensive UV detector was born.

Ul-Hasan’s research at the Department of Physical Electronics and Nanotechnology at Linköping University (LiU) has focused entirely on investigating the combination of graphene and zinc dioxide. He succeeded in producing nanolayers of both materials, then using the nanostructures to manufacture components such as field-effect transistors, LEDs, biosensors, and a small UV detector on paper as well.

“One possible area of use could be measuring UV light from the sun,” says Magnus Willander, professor and research head in Physical Electronics and Nanotechnology at LiU, Norrköping Campus.

Zinc oxide and graphene are two materials that researchers the world over are now flocking to study. Zinc oxide nanostructures can be grown easily and cheaply on almost any material at all such as paper, plastics, or semiconductors. Zinc oxide is catalytic, piezoelectric (mechanical energy converted into electricity) and is also biocompatible.

Graphene, in turn, is a two-dimensional material that consists of a single layer of carbon atoms organised into a net. It is strong, translucent, ductile, and it conducts electricity. If, like ul-Hasan, you draw lines and points with a pencil, they consist of graphite - several layers of graphene.

Ul-Hasan has also developed a chemical method for making graphene nanostructures that were later used in a number of different applications such as LEDs, transistors, and sensors.

Willander and his research group are on the cutting edge as regards studying and growing zinc dioxide nanostructures via relatively inexpensive methods that can also be used on an industrial scale. Zinc oxide is combined with materials like graphene, copper oxide, and others. Seven doctors have defended their theses just over the past few years, and more theses are on the way. New doctoral students have also been recruited.

Potential applications extend over a broad spectrum, including luminous wallpaper and walls and optoelectronics, sensitive, biocompatible sensors, energy storage in consumer electronics, and more. Over the next few years Willander will also have the opportunity to form a research group in Beijing, where the Chinese National Science Council will fund the research.

“The Chinese invest billions in nanotechnology and new materials, and I get to do what I love most,” Willander states.

Thesis: Graphene and ZnO Nanostructures for Nano- Optoelectronic & Biosensing Applications, Kamran ul-Hasan, Department of Science and Technology, Linköping University, Norrköping Campus, 2012

Related Links

• Kamran ul-Hasan
• Professor Magnus Willander
• Department of Physical Electronics and Nanotechnology at LiU

 

Monica Westman Svenselius 2012-07-11