Theoretical investigation on the structure and optical properties of Alq3 and its difluorinated derivatives

摘要

The structures of tris(8-hydroxyquinoline) aluminum (Alq3) and its difluorinated derivatives were optimized for the ground state at the B3LYP/6-31G* level and for the excited-state at the CIS/6-31G* level. At the same time, the absorption and emission spectra based on the above structures were calculated by the time-dependent density functional theory (TD-DFT) using the PBE0 method with the 6-31G* set. A significant red shift was predicted for 3,5-difluoro-substituted Alq3 while a significant blue shift for 4,6-difluoro-substituted Alq3. In addition, the reorganization energies for electron carriers (λ_e) were predicted and it was found that the derivatives are potential materials for electron transport.