New 2,6-modified BODIPY sensitizers for dye-sensitized solar cells

A series of new metal-free organic dyes with either a boron dipyrromethene (BODIPY)-phenylene or -thiophene as a π-conjugated bridge have been synthesized for application in dye-sensitized solar cells. The photophysical and electrochemical properties of these dyes were investigated and their performance as sensitizers in dye-sensitized solar cells has been measured. The structure–property relationship shows that the introduction of a methoxy group as the donor and a BODIPY-thiophene unit as the π-conjugated bridge are favorable to improve the efficiency of DSSCs. A combination of a methoxy modified donor and BODIPY-thiophene bridge possesses a stronger electron-donating ability and longer wavelength absorption band, and as a sensitizer reveals the best properties of DSSCs, whose conversion efficiency was 2.26%.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► A series of new 2,6-modified BODIPY dyes were synthesized for DSSCs. ► The highest overall efficiency, 2.26%, was achieved among these BODIPY dyes. ► Several factors influencing the efficiency of DSSCs were demonstrated.