Graphene-based material 'outperforms' indium tin oxide

GraphExeter — a new version of the world’s thinnest material capable of conducting electricity — has been created by a team from Exeter University’s Centre for Graphene Science.

The new material comprises two graphene layers sandwiched with molecules of ferric chloride that are said to improve graphene’s limited conductivity without affecting its unique transparency, strength or flexibility. GraphExeter could find use in future wearable electronics, displays and photovoltaic devices as it is mechanically flexible, lightweight, electrically conductive and optically transparent.

Until now, graphene has been unable to replace the most widespread transparent conductor in optoelectronic applications, indium tin oxide, due to its relatively poor conductivity. Indium tin oxide is, however, a finite resource that is expected to run out in 2017.

‘This improved version of graphene outperforms indium tin oxide and any other known carbon-based transparent conductor currently used in optoelectronics,’ said Dr Monica Craciun, lead researcher from Exeter University. ‘So far we have demonstrated that GraphExeter has outstanding conductivity and transparency on a scale of microns.’

The findings, published in Advanced Materials, suggest GraphExeter could eventually be used for the creation of ‘smart’ mirrors or windows with computerised interactive features.

‘Another beauty of the GraphExeter is this material is transparent over a much wider light spectrum than the typical transparent conductor,’ said Craciun. ‘In other words, if implemented in a solar panel, the GraphExeter would allow energy to be harvested over a much wider range of light than what is currently exploited, boosting the efficiency of solar panels by more than 30 per cent.’

The next step is to develop a spray-on version of the material so it can be applied on a large scale.