Electronic structure and spectral properties of the triarylamine-dithienosilole dyes for efficient organic solar cells

Abstract

The recently synthesized high-performance triarylamine dyes with the dithienosilole π-conjugated spacer for efficient organic solar cells are calculated at the density functional theory (DFT) level with the Bader approach for the quantum theory of atoms in molecule (QTAIM) analysis. The presence of stabilizing intramolecular hydrogen bonds and Van der Waals interactions in the dye molecules is predicted and the energies of these interactions are estimated. The electronic bands nature in absorption spectra of the dyes is determined by the time-dependent DFT calculations with a linear response methodology using B3LYP and BMK hybrid functionals. Relations between incident light absorption intensity in the first long-wavelength band of the dye, its polarization, HOMO–LUMO orbital nature and the driving force of electron injection to the semiconductor are discussed.