Perylene diimide-thienylenevinylene-based small molecule and polymer acceptors for solution-processed fullerene-free organic solar cells

A small molecule and a polymer based on perylene diimide and thienylenevinylene were designed and synthesized. Both small molecule and polymer exhibited excellent thermal stability with decomposition temperatures of >400 degrees C and strong absorption in the visible region (300-800 nm). These two compounds showed highest occupied molecular orbital levels of -5.57 and -5.70 eV and lowest unoccupied molecular orbital levels of -3.72 and -3.67 eV, respectively. Solution processed fullerene-free polymer solar cells based on the small molecule acceptor and the polymer acceptor afforded power conversion efficiencies of up to 0.69% and 1.00%, respectively. Comparative studies of the absorption, energy levels, charge transport, morphology and photovoltaic properties of the small molecule and polymer were carried out. (C) 2014 Elsevier Ltd. All rights reserved.