Substituted graphene nano-flakes: Defective structure and large nonlinear optical property-Zhi-ru Li

Substituted graphenes without centrosymmetry can be considered as a new acceptor-graphene model for
NLO materials and exhibit large static first hyperpolarizabilities (b0). Especially, three interesting relationships
between the defect structure and b0 value are observed. We found that the defects (for example,
the Stone–Wales and 585 defects) in graphenes can greatly enhance b0 values up to 1.4 105 au (about
1200 1030 esu), which shows that the defect is a new factor for enhancing b0 value. Meanwhile, large
HOMO–LUMO gaps (4.595–5.982 eV) and vertical ionization potential values (8.059–13.572 eV) indicate
that those substituted graphenes molecules have chemical stabilities.