Molecular fan, a radiative cooling coating technique for electronic devices has been developed. The enhanced surface emissivity and heat dissipation efficiency of the molecular fan coating are shown to correlate well with the quantization of lattice modes in active nano-materials, such as graphene and ZnO. The highly quantized G and 2D bands in the monolayer graphene dispersion have been achieved and incorporated in an organic-inorganic acrylate emulsion to form coating assembly on heat sinks for LED and CPU devices. For nano-coating, the silicone resin formulations for high temperature units (300�C) have been formulated: the aqueous emulsion containing graphene nanomaterials (RC-graphene) or nano-ZnO (RC-ZnO) with multifunctional groups for binding to substrates. The cooling results were quantified by TEM, Raman spectroscopy, voltage breakdown testing and heat dissipation measurement.The monolayer graphene dispersion is shown to lower the equilibrium junction temperature by 28 oC. The heat dissipation performance applied on LED devices shows that, at constant light brightness, the coated 50 W LED gives an enhanced cooling of 20%. The RC-graphene and RC-ZnO formulations were found to be able to cool the equilibrium temperature by 26 oC and 24 oC Celsius, respectively. Furthermore, all of these formulated nano-coating can work as a high dielectric layer (< 50 �m thick) and exhibit a breakdown voltage threshold greater than 5 kilovolts as required by high power LED.

Radiative cooling by molecular fan nanomaterial coating for high power LED applications

246th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.