Flexible Devices Based on Soybean-Derived High-Quality N-Doped Graphene

Abstract

Graphene with exceptional properties has attracted significant attention in many fields. Chemical vapor deposition has been a vital method for synthesizing high-quality graphene with controlled size, thickness, and quality. Intrinsic graphene is a zero bandgap 2D material with weak ambipolar behavior, and the transistors based on such graphene show a low on/off current ratio. It is important to achieve the controllable preparation of graphene with adjustable electrical properties. Doping the graphene with heteroatoms is a standard method to achieve this goal. Here, we demonstrate that high-quality N-doped graphene can be prepared using soybeans as the carbon source. We can control the preparation of high-quality N-doped graphene on Cu catalyst using soybean as the carbon source, including, N-doped single-crystal graphene domains and N-doped monolayer films. Electrical measurements show that the N-doped graphene exhibits an n-type behavior, indicating that doping can effectively modulate graphene’s electrical properties. Based on the high-quality N-doped graphene, we demonstrate its applications in flexible supercapacitors and skin-like electrophysiological monitors, showing high application value in wearable electronic devices.