Density functional theory study of promising polyene-diphenylaniline organic chromophores for dye-sensitized solar cell applications

Abstract

Dye-sensitized solar cells have attracted rapid interest over the recent years with prospect of emerging as a viable alternative to conventional silicon-based solar cells. Currently organic and inorganic complexes have been widely employed as sensitizers for DSSCs. One of the salient features of dye sensitizer is a strong absorption in the ultraviolet, visible and near-infrared part of the solar radiation spectrum. Light absorption and charge separation is performed by the sensitized dye molecules adsorbed on TiO2 surface. In this work, the time dependent-density functional theory was used to investigate UV–Vis absorption spectra of a series of polyene-diphenylaniline organic chromophores. The HOMO–LUMO energy levels, maximum excitation wavelength, excitation energies and light-harvesting efficiencies of selected dye molecules were simulated. The results showed that, the dyes with methoxy groups in their donor moiety show bathochromic shift and reduced HOMO–LUMO energy gap than the corresponding dyes without methoxy group. The results compare favorably well with other findings.