Functionalized Alkynylplatinum(II) Polypyridyl Complexes for Use as Sensitizers in Dye-Sensitized Solar Cells

A series of platinum(II) alkynyl‐based sensitizers has been synthesized and found to show light‐to‐electricity conversion properties. These dyes were developed as sensitizers for the application in nanocrystalline TiO2 dye‐sensitized solar cells (DSSCs). Their photophysical and electrochemical properties were studied. The excited‐state property was probed using nanosecond transient absorption spectroscopy, which showed the formation of a charge‐separated state that arises from the intramolecular photoinduced charge transfer from the platinum(II) alkynylbithienylbenzothiadiazole moiety (donor) to the polypyridyl ligand (acceptor). A lifetime of 3.4 μs was observed for the charge‐separated state. A dye‐sensitized solar cell based on one of the complexes showed a short‐circuit photocurrent of 7.12 mA cm−2, an open circuit voltage of 780 mV, and a fill factor of 0.65, thus giving an overall power conversion efficiency of 3.6 %. Electric company: A series of platinum(II) alkynyl‐based sensitizers has been synthesized and found to show light‐to‐electricity conversion properties (see graphic). A dye‐sensitized solar cell based on one of the complexes shows a fill factor of 0.65 and a power‐conversion efficiency of 3.6 %.