Ultra-high quantum yield of graphene quantum dots: Aromatic-nitrogen doping and photoluminescence mechanism

Abstract

1-3 nm nitrogen-doped graphene quantum dots with quantum yield of 0.74 are synthesized via cutting graphene oxide and in situ doping. The size is determined by the remaining graphitic domains of precursor. The doping mechanism is illustrated, and the dominant photoluminescence factor is experimentally confirmed to be the n-π∗ transition between the lattice-doped nitrogen and the conjugate structure of graphene.