New heteroleptic benzimidazole functionalized Ru-sensitizer showing the highest efficiency for dye-sensitized solar cells

• We successfully designed and synthesized Ru(II) sensitizer GS7 with a new benzimidazole ligand as electron donating group.
• This is the first report on benzimidazole based sensitizer showing high efficiency in DSSC.
• GS7 exhibited high power conversion efficiency of 6.07%.
• The IMVS data disclosed that the sensitizer GS7 exhibited a higher charge transport resistance compared to N749.
• The agreement between theoretically computed and experimental parameters is very good.

We designed and synthesized a new ruthenium complex using terpyridine as an anchoring ligand and BOC (tert-butyloxycarbonyl) protected bidentate benzimidazole derivative as an ancillary ligand, coded as GS7. The complex was characterized using 1H NMR, FTIR, elemental analysis, UV–vis spectrophotometer, and cyclic voltammetry. We also tested photovoltaic performance of this complex for dye-sensitized solar cell (DSSCs). GS7 when used as a sensitizer for DSSCs with iodine triiodide electrolyte, showed a Jsc of 15.25 mA cm− 2, a Voc of 0.576 V, a FF of 0.691 and overall power conversion efficiency of (η) 6.07%.

A new class of ruthenium complex with BOC-protected benzimidazole derivative as ancillary ligand was synthesized for DSSCs. GS7 based solar cell showed efficient panchromatic sensitization over the entire visible wavelength, showed a PCE of 6.07%.Figure optionsDownload as PowerPoint slide