▎ 摘　　要

Synthetic progress has led to growth of monodisperse colloidal graphene quantum dots large enough that the lowestenergy electronic states can be understood in terms of confined Dirac fermions. Appropriate ligands inhibit aggregation and promote solubility that now permit optical studies of excitons and biexcitons formed of Dirac fermions in ensembles of individual quantum dots. Here we review recent progress in synthesis and understanding of the optical properties and dynamics of colloidal graphene quantum dots as well as related aspects of other nanoscale graphene structures and polycyclic aromatic hydrocarbons. We highlight graphene quantum dots that are fully benzenoid and discuss challenges in studying colloidal graphene quantum dots with zigzag edges. [GRAPHICS] Graphene quantum dot (C168) consisting of 168 sp(2) hybridized C atoms. R indicates ligands. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim