Multi‐Branched Multi‐Anchoring Metal‐Free Dyes for Dye‐Sensitized Solar Cells

Abstract

Abstract Multi‐branched multi‐anchoring metal‐free dyes as photosensitizers for dye‐sensitized solar cells (DSSCs) are reviewed. The article outlines design strategies, main synthetic routes and optical and photovoltaic properties of two families of multi‐branched sensitizers: (a) D–(π–A) n (D = donor, π = π‐spacer, A = acceptor/anchoring functionality) structures containing arylamine, carbazole, phenothiazine or phenoxazine derivatives as D groups, and (b) multi‐donor multi‐anchoring architectures from interconnected mono‐branched D–π–A arms, together with X‐ and Y‐shaped dyes. Although this class has been reported only in the last five years, a variety of molecular architectures, donors, and π‐spacers have been used and combined in multi‐branched molecules. The multi‐branched geometry induces distinctive features including enhanced qualitative and quantitative optical properties, increased currents and quantum efficiencies, and control of molecular aggregation.