Design and synthesis of 2D A1-π-A2 copolymers impact on fullerene network for efficient polymer solar cells. (1st August 2018)

• Record Type: Journal Article
• Authors: Jeon, Sung Jae; Lee, Tae Ho; Han, Yong Woon; Moon, Doo Kyung
• Is Part Of: Polymer. Volume 149(2018)
• Page Start: 85
• Page End: 95
• Publication Date: 2018-08-01
• Subjects: Polymer solar cells (PSCs) -- Fullerene inter-chain packing -- Two-dimensional (2D); Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2018.04.032
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: A new building block of two-dimensional (2D) A1 -π-A2 copolymers for P(dDTPz-ID) and P(dDTPz-DTBT) was designed and synthesized. Their structures have two strong acceptor units (isoindigo and benzothiadiazole derivatives) in the backbone, respectively. It displayed a benefit of A1 -A2 building blocks, which is complementary and broad light absorption from 300 to 750 nm due to acceptors with different withdrawing strengths. Also, the introduction of dangling-thiophene, π unit allowed the formation of 2D-strcuture, which and led to effective and inter-chain packing of PC71 BM for both copolymers. Two copolymers exhibited enhanced π-π stacking properties and had predominant face-on structure, which was confirmed by XRD. We also reviewed the optical, electrochemical, morphological, charge transport properties and performance compared with A1 -A2 copolymers for P(DTPz-ID) and P(DTPz-DTBT), respectively. The inverted device fabricated with optimized condition for P(dDTPz-DTBT) showed efficient charge transport from enhanced energy alignment, high Voc and dipole moment and fine morphology, and thus obtained 5.0% of best power conversion efficiency (PCE). Graphical abstract: Image 1 Highlights: Two-dimensional (2D) A1 - π -A2 new concept of copolymers was designed and synthesized. The copolymers were characterized through GPC, TGA, UV, CV, XRD and so on. Power conversion efficiency of the best device for P(dDTPz-DTBT) was reached to 5.0%.