Controlling the morphology and hole mobility of terpolymers for polymer solar cells. Issue 16 (2nd February 2016)

• Record Type: Journal Article
• Authors: Guo, Huan; Shen, Tianpei; Wu, Fen; Wang, Guo; Ye, Linglong; Liu, Zhaoxia; Zhao, Bin; Tan, Songting
• Is Part Of: RSC advances. Volume 6:Issue 16(2016)
• Page Start: 13177
• Page End: 13184
• Publication Date: 2016-02-02
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c5ra23863c
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : A series of D1–A–D2–A terpolymers based on DPP as electron-deficient unit, thiophene-2, 5-bis((2-alkyloxy)benzene-thiophene and alkylthienyl-substituted benzodithiophene as electron-rich units have been designed and synthesized for PSC. Abstract : A series of D1–A–D2–A terpolymers based on diketopyrrolopyrrole (DPP) as electron-deficient unit (A), alkylthienyl-substituted benzodithiophene (BDTT) and thiophene-2, 5-bis(2-alkyloxy)benzene-thiophene (TBT) as electron-rich units (D) have been designed and synthesized by Stille-coupling reaction. The effects of the TBT/BDTT ratios on the thermal, photophysical, electrochemical properties and crystallinity of the copolymers were investigated using thermogravimetric analysis, UV-vis-NIR absorption spectra, cyclic voltammetry and wide-angle X-ray diffraction, respectively. Compared with the binary copolymers (PDPPHT-TBT andPDPPHT-BDTT ), the random terpolymers (PDPPHT-3TBT-BDTT, PDPPHT-TBT-BDTT andPDPPHT-TBT-3BDTT ) exhibited significant improvement in thermal stability and hole mobility, and the optical, electrochemical properties, lamellar distance and π–π* stacking distance of the random terpolymers were successfully tuned with different TBT/BDTT ratios. Bulk heterojunction polymer solar cells based on the as-synthesized terpolymers as electron donors and (6, 6)-phenyl-C61 -butyric acid methyl ester (PC61 BM) as the acceptor were fabricated. The best power conversion efficiency (PCE) of 4.18% was obtained from the terpolymerPDPPHT-TBT-BDTT .