Synthesis, characterization and evaluation of ruthenium(II) polypyridyl complexes as sensitizer for dye sensitized solar cells

Abstract

Dye sensitized solar cell is the device that is made up of metal oxide semiconductor, electrolyte and ruthenium complexes as sensitizer. This device harvest sun light and convert it to electricity, the first ruthenium complex dye used was N3. In this study, ruthenium(II) polypyridyl complexes formulated as [(RuLXLY)(NCS)2], where Lx and Ly are different types of ligands comprising bpy or phen as ancillary ligands were synthesized and characterized by FT-IR and 1H-NMR spectroscopy. The complexes were further characterized with UV-Vis, and photoluminescence (PL) spectroscopy. These dyes showed good photophysical properties, with absorption spectra dominated by metal to ligand charge transfer (MLCT) transitions in the visible region and part of the near IR (NIR) region of the electromagnetic spectrum. The solar cell fabrication with these complexes was done, using doctor blade technique, and these cells were further characterized for current- voltages (J-V) curve and solar cell efficiency test. The solar cells based on these ruthenium complexes using TiO2 as semiconductor gave good (J-V) curve, with overall efficiency (  ) between 0,2%- 1.02 %, with JSC = 0. 776-3.44 mA cm-2, VOC = +/-0.59 V and FF = 0.5-0.6 under global air mass (1.5AM) illumination using potassium iodide in acetonitrile as electrolyte.