Thieno[3,4-c]pyrrole-4,6-dione-based small molecules for highly efficient solution-processed organic solar cells

Two small molecules named BT-TPD and TBDT-TTPD with a thieno[3,4-c]pyrrole-4,6-dione (TPD) unit were designed and synthesized for solution-processed bulk-heterojunction solar cells. Their thermal, electrochemical, optical, charge-transport, and photovoltaic characteristics were investigated. These compounds exhibit strong absorption at 460-560 nm and low highest occupied molecular orbital levels (-5.36 eV). Field-effect hole mobilities of these compounds are 1.7-7.7×10(-3) cm(2) V(-1) s(-1). Small-molecule organic solar cells based on blends of these donor molecules and a acceptor display power conversion efficiencies as high as 4.62% under the illumination of AM 1.5G, 100 mW cm(-2).