This illustration shows graphene nanoflakes functionalized with amino-based and azide-based silane molecules. Image: Johan Liu; Philip Krantz, Krantz Nanoart.Heat dissipation is a severe bottleneck in the development of advanced electronic and optoelectronic devices. To get to grips with this issue, scientists at Chalmers University of Technology in Sweden, as part of an international team of researchers, have developed an efficient way of cooling electronics with functionalized graphene nanoflakes. Their results are published in Nature Communications.
“Essentially, we have found a golden key with which to achieve efficient heat transport in electronics and other power devices by using graphene nanoflake-based film,” explains Johan Liu, professor of electronics production at Chalmers University of Technology. “This can open up potential uses of this kind of film in broad areas, and we are getting closer to pilot-scale production based on this discovery.”
The researchers studied the heat transfer properties of graphene nanoflake-based films functionalized with various amino-based and azide-based silane molecules. They found that introducing the functionalization molecules improved the heat transfer efficiency of the films by over 76% compared to a reference system without the functional layer. This is mainly due to the functionalization molecules drastically reducing the contact resistance.
In addition, molecular dynamic simulations and detailed calculations revealed that the functional layer constrains the cross-plane scattering of low-frequency phonons, which in turn enhances in-plane heat-conduction of the bonded film by recovering the long flexural phonon lifetime. These results suggest that the films could be used for thermal management in electronic devices.
In the study, the scientists studied a number of functional molecules immobilized at the interfaces and the edges of the graphene nanoflake-based sheets, where they form covalent bonds. They also probed interface thermal resistance in the films, using a photo-thermal reflectance measurement technique to demonstrate that the functionalization caused improved thermal coupling.
“This is the first time that such systematic research has been done,” says Liu. “The present work is much more extensive than previously published results from several involved partners, and it covers more functionalization molecules and also more extensive direct evidence of the thermal contact resistance measurement.”
This story is adapted from material from Chalmers University of Technology, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.