A new 1H-pyridin-(2E)-ylidene ruthenium complex as sensitizer for a dye-sensitized solar cell

Abstract

The new heteroleptic ruthenium(II) complex containing a 1H-pyridin-(2E)-ylidene (PYE) ligand was synthesized and characterized using UV/Vis, FTIR, and NMR spectroscopies, mass spectrometry, elemental analysis, and cyclic voltammetry. The photovoltaic performance of the ruthenium complex as a charge transfer photosensitizer in nc-titanium dioxide based dye-sensitized solar cell was studied and compared with cis-bis(isothiocyanato)(2,2'-bipyridyl- 4,4'-dicarboxylato)(2,2'-bipyridyl-4,4'-di-nonyl)ruthenium(II) (Z907) under standard AM 1.5 sunlight. The complex CS90 gave a photocurrent density of 1.80mAcm-2, 400mV open-circuit potential, and 0.58 fill factor yielding an efficiency of 0.42% where the reference Z907 yielded an efficiency of 4.12%. The decrease in conversion efficiency observed for CS90 is attributed to a steric interaction between PYE and the TiO2 surface that prevents optimum binding and also restricts ligand dynamics that are associated with oxidation state changes. © 2013 Taylor & Francis.