6. Synthesis of Graphene Quantum Dots for Photovoltaics

Chapter 6 introduces a novel stepwise method for synthesizing graphene quantum dots (GQDs) using a combination of strong acids and hydrogen peroxide (H₂O₂) to oxidize graphite. The produced GQDs have quantum confinement effects and excellent stability. The addition of H₂O₂ enhances the oxidation process, facilitating the cleavage of graphite into smaller fragments, thereby achieving a photoluminescence (PL) peak centered between 480–520 nm. The chapter explores benefits of using graphite as a precursor, emphasizing how it helps maintain the graphitic structure, and how the functional groups and the conjugated structure influence the PL intensity. Additionally, the chapter explores the post-treatment processes, including pH modification of GQDs to neutralize the acidic solution. The resulting GQD film exhibits high PL intensity, showcasing the potential of this method in optoelectronic applications. The primary focus of this chapter is the exploration of the impact of H₂O₂ on the PL properties of GQDs and to investigate the underlying mechanisms contributing to their enhanced PL behavior.