Branched Electron-Donor Core Effect in D-π-A Star-Shaped Small Molecules on Their Properties and Performance in Single-Component and Bulk-Heterojunction Organic Solar Cells †

Star-shaped donor-acceptor molecules are full of promise for organic photovoltaics and electronics. However, the effect branching core on physicochemical properties, charge transport photovoltaic performance such materials in single-component (SC) bulk heterojunction (BHJ) solar cells has not been thoroughly addressed. This work shows comprehensive investigation six star-shaped with terminal hexyldicyanovinyl blocks linked through 2,2′-bithiophene π-conjugated bridge to different electron-donating cores as pristine fused triphenylamine, tris(2-methoxyphenyl)amine, carbazole- benzotriindole-based units. Variation strongly impacts important properties solubility, highest occupied molecular orbital energy, optical absorption, phase behavior, packing also charge-carrier mobility. The SC or BHJ comprehensively studied compared. results obtained provide insight how predict fine-tune well cells.