Dye-sensitized solar cells based on a functionally separated D–π–A fluorescent dye with an aldehyde as an electron-accepting group

Abstract

As a new class of D–π–A dye sensitizer for dye-sensitized solar cells (DSSCs), we have designed and synthesized the functionally separated D–π–A fluorescent dye YJY-1 with an aldehyde as an electron-accepting group and a carboxyl group as an anchoring group. Furthermore, not only to evaluate the usefulness of D–π–A dye sensitizers functionally separated into an electron acceptor moiety and an anchoring group, but also to gain insight into the influences of interaction between the aldehyde of the dyes and the TiO₂ surface on the photovoltaic performances of DSSCs, the D–π–A fluorescent dye YJY-2 with an aldehyde as an electron-accepting group, but without a carboxyl group, was also synthesized. It was found that the functionally separated D–π–A dye YJY-1 exhibits not only high adsorption ability onto TiO₂ film through the carboxyl group, but also efficient electron injection from the dye into the CB of TiO₂ through the aldehyde which is located close to the TiO₂ surface. This work demonstrates that the functionally separated D–π–A dyes would be expected to be one of the most promising classes of organic dye sensitizers for DSSCs.