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

Planar on-chip microsupercapacitors (POMSs) with a finger width and a gap width of 10 mu m 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 mu Wcm(-2) and energy density of 0.01 mu Whcm(-2). Moreover, the POMSs showed rapid frequency response capability, the frequency at phase angle of -45 degrees was 0.18 MHz and the corresponding time constant was 5.57 mu s. 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.