STRUCTURES AND SPECTROSCOPIC PROPERTIES OF THREE AROMATIC HETEROCYCLIC DYE PHOTOSENSITIZERS

Abstract

The ground-state structures and absorption spectra of three dyes, carbazole, phenothiazine and diphenylamine, were studied by the density functional theory (DFT) and time-dependent density functional theory (TD-DFT). The strong absorption peak, electron transition as well as the energy levels of molecular orbitals were obtained and compared in the gas and solvent phase. Furthermore, we further calculated the effect of the expanding conjugated bridge on the absorption spectra and the energy levels of molecular orbitals. Visualized method of charge difference density (CDD) was used to show the direction of charge transfer in the molecules of interest during photo-excitation.