摘要
With density functional theory（DFT） method, the optimization of molecular configurations and the calcu- lation of frontier molecular orbitals were achieved for triphenylamine（TPA）-based dye-sensitized solar cell materials at the B3LYP/6-31G（d, p） level. Time-dependent density functional theory（TD-DFT） was applied to calculating the probability of the transition from the ground state to the excited state. And UV-Vis absorption spectra were derived with Franck-Condon approximation. The conjugation length, substitution groups and spatial effects show a slight influence on the dihedral angle of the TPA group. The increase of conjugation length may cause a smaller energy gap as well as a higher highest occupied molecular orbital（HOMO） and a lower lowest unoccupied molecular orbital （LUMO）. The introduction of methoxyl group and TPA group could lower the energy gap while the HOMO and LUMO were elevated in energy.
With density functional theory（DFT） method, the optimization of molecular configurations and the calcu- lation of frontier molecular orbitals were achieved for triphenylamine（TPA）-based dye-sensitized solar cell materials at the B3LYP/6-31G（d, p） level. Time-dependent density functional theory（TD-DFT） was applied to calculating the probability of the transition from the ground state to the excited state. And UV-Vis absorption spectra were derived with Franck-Condon approximation. The conjugation length, substitution groups and spatial effects show a slight influence on the dihedral angle of the TPA group. The increase of conjugation length may cause a smaller energy gap as well as a higher highest occupied molecular orbital（HOMO） and a lower lowest unoccupied molecular orbital （LUMO）. The introduction of methoxyl group and TPA group could lower the energy gap while the HOMO and LUMO were elevated in energy.
