Aggregation‐Free Organic Dyes Featuring Spiro[dibenzo[3,4:6,7]cyclohepta[1,2‐b]quinoxaline‐10,9′‐fluorene] (SDBQX) for Dye‐Sensitized Solar Cells

Three novel organic dyes coded as FHD4‐1, FHD4‐2, and FHD4‐3 featuring spiro[dibenzo[3,4:6,7]cyclohepta[1,2‐b]quinoxaline‐10,9′‐fluorene] (SDBQX) moieties are designed to inhibit dye aggregation to improve the performance of dye‐sensitized solar cells (DSSCs). The consistent absorption onsets of FHD4‐1, FHD4‐2, and FHD4‐3 in solutions and adsorbed on TiO(2) films indicate that these dyes are aggregation‐free dyes. Therefore, coadsorption with chenodeoxycholic acid (CDCA) of these three dyes reduces the performance of DSSCs because no inhibition effect for dye aggregation is needed, but, on the contrary, the dye loading amount is reduced after addition of CDCA.