Investigation on Tunable Optical Properties and Structures of Graphene Quantum Dots Doped with Sulfur Heteroatoms

Abstract

Due to quantum confinement and edge effects, graphene quantum dots (GQDs) demonstrate numerous novel chemical/physical properties. Doping GQDs with heteroatoms is an effective way to tailor their electronic and optical properties. However, due to different synthesis methods, the potential use of GQDs doped with heteroatoms is hindered by the poor understanding of their intrinsic optical properties and mechanisms. Recently, we studied optical properties of GQDs by employing theoretical calculations, which can reveal optical mechanisms of GQDs. In this work, optical spectra, HOMO–LUMO gap, and electronic density of GQDs are calculated to reveal electron transition processes. The recombination of electron-hole pairs can result in enhanced absorption intensity. It is expected that this work will provide valuable knowledge for understanding electronic and optical properties of GQDs and give important insights for the development of methods to controllably synthesize GQDs.