Reduced Graphene Oxide-Based Dielectric Nanocomposites with Small Dielectric Relaxation Times for Emerging Dielectric Electronics with High-Frequency Performance Demands

To meet the demand of emerging devices for high-frequency dielectric performances, we proposed semiconductor polyaniline in situ modified rGO nanosheets to keep the dielectric constant stable at high frequencies. The π–π interface interaction between rGO and semiconductor polyaniline was found to block the migration of electrons, redistributing the delocalized electrons of rGO and leading to a reduction in relaxation time and a delay in the dielectric relaxation at higher frequencies. This mechanism gave the dielectric materials a stable dielectric constant at high frequencies. The dielectric relaxation time was reduced from 2.75 × 10–8 to 5.68 × 10–10 at a filler load of 10 wt %. The dielectric constant only decreased by 19% from 100 to 1 × 108 Hz. For the same range, unmodified rGO showed an 85% decrease. This mechanism could also further increase the dielectric constant and decrease the dielectric loss. This has a great potential for emerging high-frequency devices (DC/DC converter, sensors, energy harvesters, etc.).