DFT Studies on the electronic structures of indoline dyes for dye-sensitized solar cells

A series of indoline dyes with promising efficiency for dye-sensitized solar cells (DSSCs) were studied using the density Functional theory at the B3LYP/6-31g (d) level. The ground-state geometries, electronic structures and absorption spectra of these dyes are reported. The calculated results indicate that the energy levels of the HOMOs and LUMOs of these dyes are advantageous for electron injection. Their intense and broad absorption bands as well as favorable excited-state energy levels are key factors for their outstanding efficiencies in DSSCs.