Rapid and green synthesis of complementary D-A small molecules for organic photovoltaics

Abstract Two push-pull molecules with close molecular structures have been synthesized through two green steps, direct heteroarylation and Knoevenagel condensation. The electronic properties and the basic bilayer heterojunction solar cells demonstrate that the two molecules are complementary in term of light absorption. Thus solar cells using a blend of the two molecules present higher power conversion efficiencies, reaching 3%, than the cells made from each compound alone.