Study on squarylium cyanine dyes for photoelectric conversion

Abstract

For photoelectric conversion, three of squarylium cyanine dyes were synthesized and their photoelectrochemical parameters were improved with increase in the adsorption ability of the dyes on nanocrystalline TiO 2. A relatively high photoelectric conversion efficiency of 2.17% and the top incident photon-to-photocurrent conversion efficiency of 6.2% at 650 nm for the dye of highest adsorption ability among the three were obtained. Meanwhile, doping cis-Ru[4,4′-(LL)] 2 (NCS) 2 with 1% of the above-mentioned dye (molar ratio) as a photosensitizer, the photoelectrochemical solar cell made an efficient complement to light-harvesting capacity in almost the whole visible range with the photoelectric conversion efficiency increasing by 12% relative to that of pure cis-Ru[4,4′-(LL)] 2 (NCS) 2 (L=2,2′-bipyridyl-4,4′-dicarboxylate).