Evaluation of noble metal decorated GNP reinforced Cu composite heat sinks for thermal performance of LED light

Abstract

Thermal management is critical for the durability of smart electronic devices, as high current densities generate excessive heat that fully dense heat sinks cannot effectively dissipate. Conductive and convective heat transfer methods, such as combining thermally conductive metals with cooling fans, are challenging due to compact device designs. In this study, we investigate the thermal properties of noble metal-decorated graphene nanoplatelet-reinforced Cu composites (Au-GNP/Cu, Ag-GNP/Cu, and Ag-N-GNP/Cu) with optimized porosity (i.e., lowest and highest), building on our previous work on their physical and mechanical properties. The thermal performance of these composites as heat sinks for LED lights was compared to undecorated GNP/Cu, sintered Cu, and commercial Cu. Decorated GNP/Cu composites exhibited enhanced thermal conductivity over undecorated GNP/Cu and sintered Cu, though values remained below commercial Cu due to porosity. High-porosity samples demonstrated superior cooling, with 0.1-Ag-GNP/Cu (22.94 % porosity) reducing LED operating temperatures by 15.83 % compared to sintered Cu. Sintered Cu (18.64 % porosity) also outperformed commercial Cu (0.11 % porosity), lowering LED temperatures by 8.57 %, highlighting the role of porosity in convective heat transfer. LED Luminous efficiency remained above 90 % for all composites, peaking at 97.21 % for 0.1-Ag-GNP/Cu. The study concludes that Ag-GNP/Cu composites effectively enhance thermal management through combined conductive and convective mechanisms, offering a promising solution for compact electronic devices.