120th General Meeting of the KCS

Type Poster Presentation
Area Polymer Chemistry
Room No. Exhibition Hall 2+3
Time 10월 20일 (금요일) 13:00~14:30
Code POLY.P-3
Subject Highly Efficient Regioregular Terpolymers Containing Fluorine Atoms on Bithiophene Segment Processed from Halogen-Free Solvent
Authors Soyoung Jang, YOUNGU LEE*
Department of Energy Systems Engineering, Daegu Gyeongbuk Institute of Science & Technology, Korea
Abstract Organic solar cells (OSCs) have attracted significant interest due to cost-effective, lightweight, flexibility and large-area fabrication. Bulk heterojunction (BHJ) in which typically a donor polymer is blended with electron acceptor material such as fullerene derivative has been predominantly used as a typical active layer. However, in order to overcome the limitations of the alternating push-pull chain approach, terpolymer design with regioregular alternating D1-A-D2-A strategy has been explored intensively for designing efficient electron donor. Recently, we synthesized a new series of fluorinated benzothiadiazole (FBT)-based terpolymers comprising two donating units, quaterthiophene (QT, D1) and benzo[1,2-b:4,5-b]dithiophene (BDT, D2). Furthermore, we introduced two and/or four fluorine atoms on bithiophene unit and called them PfBT4T-BDT, PfBT4T2F-BDT and PfBT4T4F-BDT, respectively to investigate how increasing the number of fluorine atoms affects the physical properties and OSC device performances. Due to fluorine substitution, PfBT4T2F-BDT and PfBT4T4F-BDT showed deeper HOMO level compared to PfBT4T-BDT. In addition, increase of the number of fluorine atoms from 0 to 4 led to enhanced absorption coefficients and promoted exciton dissociations due to suppressed recombination process, thus remarkably improved Jsc values. Therefore, the bulk-heterojunction OSC device based on PfBT4T4F-BDT and diphenylether (DPE) additive showed a high power conversion efficiency (PCE) of 8.45%, while the OSC devices based on PfBT4T-BDT, PfBT4T2F-BDT with DPE exhibited PCE of 6.15% and 7.54%, respectively.
E-mail jangsy106@gmail.com