Graphene Retains Conductivity on a Substrate

Since it was first discovered in 2004, the two-dimensional carbon compound graphene has been hailed as one of the most promising materials to have hit the market in years. Originally derived from 3D graphite, the material exhibits superior electron mobility, mechanical strength and thermal conductivity, which are all traits needed to create more advanced electronic equipments. Scientists stumbled upon many issues with obtaining graphene along the way, but gradually they are beginning to clear out. Recently, a team showed that graphene maintained its high thermal conductivity when supported by a substrate.

The material was known to do so when it was on its own, but the fact that it can do the same while supported by another layer is tremendous news. It means that it could be used successfully in the electronics of tomorrow, which will most likely function at the nanoscale, rather than at the microscale, as it is currently the case. The international collaboration that made the discovery features theoretical physicists and materials engineers from the University of Texas in Austin (UTA), and the Boston College, in the US, who worked with colleagues from the Commission for Atomic Energy, in France.

Their main finding was that the thin, atom-thick films of graphene could transfer heat about 50 times more efficiently than silicon thin films, which are used widely in today's electronics devices. The carbon compound also exceeds the performances of copper thin film by about 200 percent, the team reports in a paper published in the April 9 issue of the esteemed publication Science. This trait is crucial, given that modern electronics become smaller and smaller, which means that they also need to become capable of more advanced heat dispersion.

“As theorists, we're much more detached from the device or the engineering side. We're more focused on the fundamentals that explain how energy flows through a sheet graphene. We took our existing model for suspended graphene and expanded the theoretical model to describe this interaction that takes place between graphene and the substrate and the influence on the movement of heat through the material and, ultimately, it's thermal conductivity,” Boston College Professor of Physics David Broido, who has also been a coauthor of the new study, says.