N-Doped Graphene-like Film/Silicon Structures as Micro-Capacitor Electrodes

Currently, the miniaturization of portable and autonomous devices is challenging for modern electronics. Graphene-based materials have recently emerged as one of the ideal candidates for supercapacitor electrodes, while Si is a common platform for direct component-on-chip integration. We have proposed the direct liquid-based CVD of N-doped graphene-like films (N-GLFs) on Si as a promising way to achieve solid-state on-chip micro-capacitor performance. Synthesis temperatures in the range from 800 degrees C to 1000 degrees C are investigated. Capacitances and electrochemical stability of the films are evaluated using cyclic voltammetry, as well as galvanostatic measurements and electrochemical impedance spectroscopy in 0.5 M Na2SO4. We have shown that N-doping is an efficient way to improve the N-GLF capacitance. 900 degrees C is the optimal temperature for the N-GLF synthesis with the best electrochemical properties. The capacitance rises with increasing film thickness which also has an optimum (about 50 nm). The transfer-free acetonitrile-based CVD on Si yields a perfect material for microcapacitor electrodes. Our best value of the area-normalized capacitance (960 mF/cm(2)) exceeds the world's achievements among thin graphene-based films. The main advantages of the proposed approach are the direct on-chip performance of the energy storage component and high cyclic stability.

Automated summary

Researchers have developed nitrogen-doped graphene-like films (N-GLFs) through direct liquid-based chemical vapor deposition on silicon substrates. They found that a synthesis temperature of 900°C and a film thickness of about 50 nm resulted in the highest capacitance, exhibiting excellent electrochemical properties. The area-normalized capacitance of the N-GLFs reached 960 mF/cm², surpassing previous achievements in thin graphene-based films.