New organic dyes comprising carbazole, iminodibenzyl, or phenothiazine moieties, respectively, as the electron donors, and cyanoacetic acid or acrylic acid moieties as the electron acceptors/anchoring groups were synthesized and characterized. The influence of heteroatoms on carbazole, iminodibenzyl and phenothiazine donors, and cyano-substitution on the acid acceptor is evidenced by spectral, electrochemical, photovoltaic experiments, and density functional theory calculations. The phenothiazine dyes show solar-energy-to-electricity conversion efficiency (eta) of 3.46-5.53%, whereas carbazole and iminodibenzyl dyes show eta of 2.43% and 3.49%, respectively.
Keywords: absorption; donor; electrochemistry; organic dyes; photovoltaic materials.