R. Vittal

Linkage of N3 dye to N3 dye on nanocrystalline TiO2 through trans-1,2-bis(4-pyridyl)ethylene for enhancement of photocurrent of dye-sensitized solar cells

Linking of N3 dye to another TiO2-attached N3 dye rendered an enhanced short-circuit photocurrent and thereby higher efficiency for the dye-sensitized solar cell with the pertinent TiO2 film electrode.

Dinuclear Ru(II) dyes for improved performance of dye-sensitized TiO2 solar cells

In this study, a Ru(II) dye was linked to another TiO2-attached Ru(II) dye through the linker, trans-1,2-bis(4-pyridyl)ethylene (tbpe), and such TiO2 film electrodes were used in dye-sensitized solar cells (DSSCs). The mononuclear Ru(II) dyes selected were N3 ([Ru(dcbpyH2)2(NCS)2], dcbpyH2 = 2,2′-bipyridyl-4,4′-dicarboxylic acid), N719 ([(C4H9)4N]2[Ru(dcbpyH)2(NCS)2]), and N749 ([(C4H9)4N]3[Ru(tcterpy)(NCS)3]·3H2O, tcterpy = 4,4′,4″-tricarboxy-2,2′:6′,2″-terpyridine). The photovoltaic characteristics of the DSSCs prepared using the above-mentioned TiO2 film electrodes were examined. The DSSC with the dinuclear dye, N719-tbpe-N719 had the highest short-circuit photocurrent density (Jsc) and thereby the highest conversion efficiency compared with the other cells sensitized by the other mononuclear or dinuclear Ru(II) dyes. The Jsc enhancement was attributed to an increase in the conduction band electrons of TiO2 due to the efficient intramolecular charge and energy transfer from the linked dye molecule to the immobilized molecule through a chain of conjugated double bonds in tbpe. These transfers are explained based on the relative LUMO levels of the dyes.