Planar on-chip microsupercapacitors based on aminated graphene quantum dots with high areal power density and rapid frequency response capability

Abstract

Planar on-chip microsupercapacitors (POMSs) with a finger width and a gap width of 10 μm were fabricated based on aminated graphene quantum dots electrode films by modified liquid-air interface self-assembly method, photolithography and oxygen plasma etching, and they had the areal power density of 154.14 μWcm−2 and energy density of 0.01 μWhcm−2. Moreover, the POMSs showed rapid frequency response capability, the frequency at phase angle of −45° was 0.18 MHz and the corresponding time constant was 5.57 μs. After 10000 charge and discharge cycles, the capacitance retention rate was 93%. Doping of nitrogen can improve the conductivity of the electrode films and the presence of amino groups can improve surface modification of the electrode films.