Electrical Double Layer Capacitance in a Graphene-embedded Al(2)O(3) Gate Dielectric

Graphene heterostructures are of considerable interest as a new class of electronic devices with exceptional performance in a broad range of applications has been realized. Here, we propose a graphene-embedded Al(2)O(3) gate dielectric with a relatively high dielectric constant of 15.5, which is about 2 times that of Al(2)O(3), having a low leakage current with insertion of tri-layer graphene. In this system, the enhanced capacitance of the hybrid structure can be understood by the formation of a space charge layer at the graphene/Al(2)O(3) interface. The electrical properties of the interface can be further explained by the electrical double layer (EDL) model dominated by the diffuse layer.