Some drawbacks concerning the application of anthocyanidins as sensitizers in dye-sensitized solar cells (DSSCs) are low efficiency and stability of are photovoltaic devices. We investigated structural effects and electronic contributions of anthocyanidins (dye-sensitizers) to improve the efficiency of DSSCs. Anthocyanidins from crude and purified extracts of T. cattapa and H. sabdariffa as well as pure compounds of cyanidin, pelargonidin, delphinidin and malvidin were employed as sensitizers and titanium dioxide as semiconductor in fabrication of solar cells. Efficiencies of DSSCs were...