Malaysian Journal of Chemistry, 2017, Vol. 20(1), 24 – 32

Preparation and Properties of Fluorene-based Thienothiophene Substituted Benzothiadiazole Copolymer for the Application of Polymeric Solar Cells

Mohd Sani Sarjadi1*, Shu Er Tan1 and Ahmed Iraqi2
1Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS,
88400 Kota Kinabalu, Sabah
2Department of Chemistry, University of Sheffield, Sheffield S37HF, UK
*Corresponding author: (e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.)

 Received: January 2018; Accepted: June 2018


Polymer solar cells (PSCs) have been intensively studied by researchers in order to improve their power conversion efficiency (PCE). The current PCE achievement has successfully surpassed 10%, yet it is still far laging from their inorganic counterparts. Hence, there is still a lot of room for improvement of the organic photovoltaics. This work presents a new class of fluorene-donor/benzothiadiazole-acceptor copolymers with thienothiophene as the spacer. Poly(9,9-dioctyl-9H- fluorine-alt-5,6-bis(octyloxy)-4,7-di(thieno[3,2-b] thiophen-2- yl)benzo[c][1,2,5]thiadiazole) (P1) was synthesized through the well-known Suzuki’s cross-coupling reaction and the reported Mw and PDI values were 20 kDa and 2.6, respectively. The optical and electrochemical band gaps achieved by this P1 were 2.03 eV and 1.98 eV, respectively, which could still be narrowed down by further modification of the chemical structure. Moreover, the P1 was found to have good thermal stability up to 433°C. This research could provide an insight into the relationship between the chemical structure and polymeric characteristics for future designation of the PSCs.

Key words: Conjugated polymers; thienothiophene; benzothiadiazole; Suzuki cross-coupling; solar cells


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