Diketopyrrolopyrrole-based blue dyes in dye-sensitized solar cells (DSCs) exhibit promise for building-integrated photovoltaics, but their efficiency is compromised by dye aggregation-induced charge recombination. Novel bile acid derivative co-adsorbents featuring bulky hydrophobic substituents at the 3-β position were synthesized to address this challenge. These molecules, designed to modulate intermolecular electronic interactions, effectively altered the TiO