A Solution-Processable Star-Shaped Molecule for High-Performance Organic Solar Cells

A new 3D, star-shaped, donor-acceptor-donor (D-A-D) small molecule with triphenylamine as the core and donor unit, benzothiadiazole as the bridge and acceptor unit, and hexylterthiophene as the arm and donor unit is synthesized. Photovoltaic devices based on the blend of this compound and [6,6]-phenyl-C-71-butyric-acid-methyl-ester (PC71BM) exhibited power conversion efficiencies as high as 4.3%, which is among the highest reported for solution-processed organic solar cells based on small molecules.