Synthesis and Photovoltaic Properties of Novel Ruthenium(II) Sensitizers for Dye-sensitized Solar Cell Applications

摘要

Three heteloleptic ruthenium sensitizers, Ru(L)(L )(NCS)2 [L = 4,4'-dicarboxylic acid-2,2'-bipyridine, Ru-T1: L~1 = (E)-2-(4'-methyl-2,2'-bipyridin-4-yl)-3-(thiophen-2-yl)acrylomtrile, Ru-T2: L~2 = (E)-3-(5'-hexyl-2,2'-bithiophen-5-yl)-2-(4'-methyl-2,2'-bipyridin-4-yl)acrylonitrile, and Ru-T3: L~3 = (E)-3-(5"-hexyl-2,2':5',2"-terthiophen-5-yl)-2-(4'-methyl-2,2'-bipyridin-4-yl)acrylonitrile)], were synthesized and used as photosensitizers in nanocrystalline dye-sensitized solar cells (DSSCs). The introduction of the 3-(5-hexyloligothiophen-5-yl)acrylonitrile group increased the conjugation length of the bipyridine donor ligand and thus improved their molar absorption coefficient and light harvesting efficiency. DSSCs with the configuration of SnO2: F/TiO2/ruthenium dye/liquid electrolyte/Pt devices were fabricated using these Ru-T1 ～ T3 as a photosensitizers. Among the devices, the DSSCs composed of Ru-T2 exhibited highest power conversion efficiency (PCE) of 2.84% under AM 1.5 G illumination (100 mW/cm2).