Photolithographic fabrication and electrochemical characterization of planar on-chip micro-supercapacitors based on nitrogen and oxygen co-doped graphene quantum dots with superior capacitance retention rates

Abstract

Compared with graphene, nitrogen and oxygen co-doped graphene quantum dots can make up for the limitation of graphene active sites. Here, we demonstrated the fabrication of planar on-chip micro-supercapacitors based on nitrogen and oxygen co-doped graphene quantum dots. The interdigital micro-electrodes were prepared on the surface of the electrode thin film by the photolithographic technique. Notably, the electrochemical performance of the micro-supercapacitors had significantly increased. The area capacitance was 18.74 μF cm−2. Furthermore, this work offered the areal energy density of 2.60 nWh cm−2 and the areal power density of 116.43 μW cm−2. After 10,000 cycles at 5000 Vs−1, the capacitance retention rate of 99.23% was obtained. Meantime, the corresponding time constant was 10.03 μs.