A research team have made a breakthrough discovery with graphene, which is a material that could play a major role in keeping laptops and other electronic devices from overheating. A key finding is the possibility of a strong enhancement of thermal conduction properties of isotopically pure graphene without substantial alteration of electrical, optical and other physical properties. Isotopically pure graphene can be ideal for many practical applications.
The research team were led by Alexander Balandin, a professor of electrical engineering at the UC Riverside Bourns College of Engineering, and Professor Rodney S. Ruoff at the University of Texas at Austin. The team also included researchers from the University of Texas at Dallas and Xiamen University in China. Based on their research, the team concluded that the thermal properties of isotopically engineered graphene are far superior to those of graphene in its natural state.
As a result of the their research, graphene is one step closer to being used as a thermal conductor for managing heat dissipation in everything from electronics to photovoltaic solar cells to radars. Graphene is a single-atom thick carbon crystal with unique properties, including superior electrical and heat conductivity, mechanical strength and unique optical absorption.
The researchers used the optothermal Raman method, which is a thermal conductivity measuring technique developed by Balandin. In 2008, Balandin and his group members demonstrated experimentally that graphene is an excellent heat conductor. They also developed the first detailed theory of heat conduction in graphene and related two-dimensional crystals.
Naturally occurring carbon materials, including graphene, are made up of two stable isotopes: about 99% of 12C (carbon 12) and 1% of 13C (carbon 13). The difference between isotopes is in the atomic mass of the carbon atoms. The removal of just about 1% of carbon 13, also called isotopic purification, modifies the dynamic properties of crystal lattices and affects their thermal conductivity.
According to Balandin, graphene will gradually be incorporated into different devices. Initially, it will most likely be used in some niche applications such as thermal interface materials for chip packaging or transparent electrodes in photovoltaic solar cells or flexible displays. In a few years, it could be used with silicon in computer chips, for example as interconnect wiring or heat spreaders. It also has the potential to benefit other electronic applications, including analog high-frequency transistors, which are used in wireless communications, radar, security systems and imaging.
More info: The University of California, Riverside