Photolithographic Fabrication of Planar On-Chip Micro-Supercapacitors Based on Aminated Graphene Quantum Dots with Comprehensive Electrochemical Performance

Abstract

Nowadays, more and more electrode materials were used to fabricate micro-supercapacitors (MSCs). The graphene quantum dots were widely used due to the abundant edge defects, good conductivity, multiple active sites and other excellent characteristics. The aminated graphene quantum dots (A-GQDs) not only had the above characteristics, but also further improved the ion channel between the electrolyte and the electrode surface, and increased the transmission rate between the electrode interface. In this work, a modified liquid-air interface self-assembly method was used to fabricate the A-GQDs films on the silicon wafer for MSCs. Cyclic voltammetry measurements showed that the energy density of the MSCs was 10.21 nWh cm−2 at 0.1 V s−1 and the power density was 113.55 μW cm−2. The flat design of interdigitated electrodes can improve the frequency response with time constant as low as 1.23 μs. There is still a high areal capacitance (73.5 μF cm−2) which benefit from the narrow electrode width and the film thickness on the order of 101 nanometers. It can be seen that A-GQDs can be used as a new type of high-activity, low-cost electrode materials, suitable for high performance supercapacitors.