Open AccessImproved performance of dye-sensitized solar cells by tuning the properties of ruthenium complexes containing conjugated bipyridine ligands
Author(s) -
Hong Minh Nguyen,
Duc Nghia Nguyen,
Nakjoong Kim
Publication year - 2010
Publication title -
advances in natural sciences. nanoscience and nanotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.476
H-Index - 40
ISSN - 2043-6262
DOI - 10.1088/2043-6254/1/2/025001
Subject(s) - ruthenium , dye sensitized solar cell , molar absorptivity , bipyridine , photochemistry , conjugated system , chemistry , thiophene , cyclic voltammetry , homo/lumo , 2,2' bipyridine , absorption spectroscopy , absorption (acoustics) , materials science , organic chemistry , electrochemistry , molecule , polymer , crystal structure , catalysis , physics , electrode , quantum mechanics , optics , electrolyte , composite material
Three heteroleptic ruthenium complexes cis -[ Ru ( H 2 dcbpy )( L )( NCS ) 2 ], where H 2 dcbpy is 4,4′-dicarboxy-2,2′-bipyridine and L is 4-(4-(N,N-di-(p-anisyl)amino)styryl)-4′-methyl-2,2′-bipyridine (Dye-1), 4-(4-(N,N-di-(p-hexyloxyphenyl)amino)styryl)-4′-methyl-2,2′-bipyridine (Dye-2) or 4-(5-(N,N-di-(p-hexyloxyphenyl)-amino)-thiophene-2-yl-ethenyl)-4′-methyl-2,2′-bipyridine (Dye-3) have been synthesized and characterized. The influence of differently conjugated bipyridine ligands on these complexes was studied using UV-Vis spectroscopy and cyclic voltammetry. These heteroleptic complexes show appreciably broad absorption ranges and quite high extinction coefficients. These new dyes were used as photosensitizers in nanocrystalline TiO 2 dye-sensitized solar cells. It was found that the difference in light-harvesting property between Dye-1, Dye-2 and Dye-3 is associated mainly with molar extinction coefficients and alignment of the HOMO–LUMO energy levels. The power conversion efficiencies of solar cells based on Dye-1 and Dye-2 are 4.21% and 4.41%, while Dye-3 delivered a lower efficiency of 2.88% under the same device fabrication and measurement conditions.