Tiny crystals

researchers have discovered a way to use the spherical ‘buckyball’ molecule C60 to make tiny pure carbon nanocrystals, which could be used in solar cells and gas sensors.

By mixing two liquids together, one of which contains C60, at low temperatures, lozenge-shaped crystals with widths of 80nm are created, much smaller than possible by other methods. The electronic properties of the C60 molecules that make up the small crystals are ideal for making nanoelectronic devices and may allow researchers to accelerate the development of these nanotechnologies.

The crystals, known as fullerites, are produced in high yield and their shape can be controlled through the variation of solvent, concentration and temperature, making them ideal for experimentation. As a result of this research, existing models of fullerite growth will need re-evaluating as these models predict a minimum size of 400nm, well above that demonstrated by the team.

Possible applications of fullerite rods include adsorbents, catalysts and membranes due to their relatively high surface-area-to-volume ratio. Devices that may benefit from such materials include organic transistors, optical devices, thin film organic solar cells, organic light-emitting diodes and photodetectors.

Researcher Lok Cee Chong said: ‘The ability to control fullerite growth on a nanoscale may lead to a number of exciting applications. We are just beginning to obtain glimpses of these in my current work as I complete my PhD.’

Dr Richard Curry, who leads this research, said: ‘The results of this work are of immediate significance to a wide range of technologies that use organic materials. These new nanoscale carbon materials will allow us to continue to develop enhanced devices such as sensors and solar cells to address the grand challenges facing society today.’