Panchromatic light harvesting and record power conversion efficiency for carboxylic/cyanoacrylic Fe(ii) NHC co-sensitized FeSSCs

Fe(ii) pyridyl-NHC sensitizers bearing thienylcyanoacrylic (ThCA) anchoring groups have been designed and characterized with the aim of enhancing the metal to surface charge separation and the light harvesting window in iron-sensitized DSSCs (FeSSCs). In these new Fe(ii) dyes, the introduction of the ThCA moiety remarkably extended the spectral response and the photocurrent, in comparison with their carboxylic analogues. The co-sensitization based on a mixture of a carboxylic and a ThCA-iron complex produced a panchromatic absorption, up to 800 nm and the best photocurrent and efficiency (J(sc): 9 mA cm(-2) and PCE: 2%) ever reported for an FeSSC.

Automated summary

Fe(ii) pyridyl-NHC sensitizers with thienylcyanoacrylic (ThCA) anchoring groups were designed to improve metal to surface charge separation and the light harvesting window in FeSSCs. The introduction of the ThCA moiety significantly expanded the spectral response and photocurrent compared to carboxylic analogues. Co-sensitization using a mixture of carboxylic and ThCA-iron complex achieved panchromatic absorption up to 800 nm and the highest reported photocurrent and efficiency (J(sc): 9 mA cm(-2) and PCE: 2%) for an FeSSC.