Solution-processable small molecules based on thieno[3,4-c]pyrrole-4,6-dione for high-performance solar cells

New series of thieno[3,4-c]pyrrole-4,6-dione(TPD)-based small molecules with donor-acceptor-donor structure were synthesized by palladium(0)-catalyzed Stille coupling reaction. The thermal, electrochemical, optical, charge transport, and photovoltaic properties of these small molecules were examined. These molecules exhibit strong absorption at 460-490 nm and low HOMO levels (-5.26 to -5.34 eV). Field-effect hole mobilities of these molecules are 0.8-1.3 x 10(-3) cm(2) V-1 s(-1). Solution processed bulk heterojunction organic solar cells based on the blends of these molecule donors and PC71BM acceptor exhibit power conversion efficiencies as high as 3.31% under AM1.5, 100 mW cm(-2). (C) 2012 Elsevier B.V. All rights reserved.