Benzodichalcogenophene-diketopyrrolopyrrole small molecules as donors for efficient solution processable solar cells

Three small molecules named BDTDPP, TBFDPP and BDFDPP are designed and synthesized with alkoxy-substituted benzodichalcogenophene derivatives as donor unit while diketopyrrolopyrrole unit as acceptor unit, the investigation results show that all three small molecular materials possess favorable solubility, excellent thermal stability, broad absorption spectra and suitable electrochemical energy level. The bulk heterojunction devices based on these three small molecular materials show the power conversion efficiencies up to 3.19%, 2.82% and 2.81%, respectively. When adding 0.3% (v/v) 1,8-diiodooctane as additives, the power conversion efficiencies were further improved to 3.95%, 3.72% and 3.41%, respectively. The investigations show that all three benzodichalcogenophene-diketopyrrolopyrrole derivatives have great potential in the design of high performance optoelectronic materials. (C) 2017 Elsevier B.V. All rights reserved.