Synthesis and characterization of a wide-bandgap polymer based on perfluorinated and alkylthiolated benzodithiophene with a deep highest occupied molecular orbital level for organic photovoltaics |
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| Authors: | Hyobin Ham Hee su Kim Do-Hoon Hwang In-Nam Kang |
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| Institution: | 1. Department of Chemistry, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, Republic of Korea;2. Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Busan, Republic of Korea |
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| Abstract: | A perfluorinated and alkylthiolated benzodithiophene (BDT)-ttTPD-based donor polymer (P2FS-ttTPD) was synthesized via a Stille polymerization, and found to have a number average molecular weight (Mn) of 13,000 g/mol (Đ = 2.3). P2FS-ttTPD has a wide bandgap (1.96 eV) and a deep highest occupied molecular orbital (HOMO) level (−5.70 eV). The perfluorination and alkylthiolation of the polymer backbone lower the polymer's HOMO level significantly. The hole and electron mobilities of P2FS-ttTPD were determined to be 1.12 × 10−4 and 9.38 × 10−7 cm2/V s, respectively. Polymer solar cell devices prepared with a P2FS-ttTPD:IT-4F (1:1) blend as the active layer were found to exhibit power conversion efficiencies of 4.15%, a short-circuit current density (JSC) of 10.29 mA/cm2, an open-circuit voltage (VOC) of 0.97 V, and a fill factor of 41.6%. The (1:1) blend devices were found to exhibit high VOC and low Eloss values. |
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| Keywords: | conjugated polymers fluorination functionalization of polymers heteroatom-containing polymers organic solar cell organic solar cells |
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