Graphene-based film can super cool LEDs Researchers at Chalmers University of Technology have developed a method for efficiently cooling electronics using graphene-based film.

According to the researchers, the graphene film has a thermal conductivity capacity that is four times that of copper.

Significantly the team has developed a graphene film that  can be attached to silicon substrates.

Research team leader Johan Liu, professor at Chalmers University of Technology, writes:

    �But the methods that have been in place so far have presented the researchers with problems and it has become evident that those methods cannot be used to rid electronic devices off great amounts of heat, because they have consisted only of a few layers of thermal conductive atoms.

    �When you try to add more layers of graphene, another problem arises, a problem with adhesiveness. After having increased the amount of layers, the graphene no longer will adhere to the surface, since the adhesion is held together only by weak van der Waals bonds.�

    �We have now solved this problem by managing to create strong covalent bonds between the graphene film and the surface, which is an electronic component made of silicon,� he continues.

The stronger bonds result from so-called functionalisation of the graphene, i.e. the addition of a property-altering molecule. Having tested several different additives, the Chalmers researchers concluded that an addition of (3-Aminopropyl) triethoxysilane (APTES) molecules has the most desired effect.

When heated and put through hydrolysis, it creates so-called silane bonds between the graphene and the electronic component (see picture).

The researchers have shown that the in-plane thermal conductivity of the graphene-based film, with 20 micrometer thickness, can reach a thermal conductivity value of 1600 W/mK, which is four times that of copper.

A likely application says Johan Liu is the integration of graphene-based film into LEDs, lasers and radio frequency components for cooling purposes.