A Theoretical Study of Nonlinear Optical Properties for Stilbene Grafted to Carbon Nanotubes

DFT method was used to calculate the equilibrium geometries, electron structures and first-hyperpolarizabilities of grafted SWCNT (4,4) by organic chromophore stilbene at B3LYP/6-31G* level. ZINDO method was also used to calculate first-and second-hyperpolarizabilities. The calculated results show that stilbene graftings make the energy gap a little reduced and the maximum absorption wavelength red shifted, however grafting of stilbene breaks the symmetry of pure nanotube and lets hyperpolarizability increase obviously. We also found that grafting on tube mouth results in better nonlinear for their better conjugation and amide bond-linking shows bigger hyperpolarizabilities relative to direct bond-linking.