On-silicon supercapacitors with enhanced storage performance

Abstract

The expanding development of portable electronic devices and ubiquitous sensing systems has created a strong demand for efficient miniaturized energy storage units, with planar geometries and capable of being integrated on a silicon platform. Generally, the performance of thin-film storage devices, including using graphene, is dramatically limited by their low surface area for ion-exchange. We had recently shown that a higher number of graphene layers does not translate into higher storage performance. Here we show a way to overcome this limitation and achieve a maximum accessible area for ion exchange. A repeated graphitization strategy using a nickel catalyst on epitaxial silicon carbide films on silicon yields few-layers graphenic nanocarbon electrodes with prominent edge defects, facilitating the intercalation between multiple graphenic sheets while maintaining overall a high electrode conductivity.