Defects and Dopants in graphene: Quantum Capacitance and Thermoelectric properties

The semi-metallic nature of pristine graphene with very low density of electronic states (DOS) at the Fermi level results in poor thermoelectric properties and a low quantum capcitance. The introduction of defects and dopants in graphene leads to configuration dependent changes in DOS. We prepared defected graphene using chemical vapor deposition and Ar ion irradiation. By using Raman spectroscopy, electrochemistry, and thermoelectric measurements, we will show that quantum capacitance of graphene is highly sensitive to the configuration of dopants. Thermoelectric properties of graphene also show significant changes with different types of defects and dopants. Our experimental observations will be discussed along with density functional theory calculations.