TY - JOUR
T1 - Fluorination on electron-deficient units of benzothiadiazole-based donor-acceptor conjugated polymers for novel fullerene-based organic solar cells
AU - Du, Zhengkun
AU - Bao, Xichang
AU - Andersen, Christoffer Pajbjerg
AU - Didriksen, Charlotte Bøgild
AU - Wang, Junyi
AU - Lin, Meng Chang
AU - Cao, Zhong
AU - Yu, Donghong
N1 - Funding Information:
M.-C. Lin and Z. Du acknowledge the financial support provided by the Qingdao Scientific and Technological Innovation High-level Talents project: Aluminium-ion power and energy-storage battery (No.17-2-1-1-zhc) and the Taishan Scholar Project of Shandong Province, China (No. tsqn20161025). D.Y. thanks the support of Hunan Furong Scholarship, China, and Sino-Danish Centre for Educational and Research.
Publisher Copyright:
© 2021 International Solar Energy Society
PY - 2021/5/15
Y1 - 2021/5/15
N2 - Three new donor-acceptor (D-A) conjugated polymers based on benzo[1,2-b:4,5-b′]dithiophene (BDT) and benzo[c][1,2,5]thiadiazole (BT), namely, PB-BT, PB-BTf and PB-BTPf, were synthesized with different substituents (Hydrogen atoms, Fluorine atoms and fluorophenyl groups) on BT unit. Experimental results and theoretical calculations indicate that molecularly tuning of side chains on BT moeity simultaneously influences the energy levels and intermolecular packing of the resulted polymers by modulating their electron affinity and molecular coplanarity. The polymer solar cells (PSCs) based on a blend of PB-BTf/[6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) exhibits the best photovoltaic performance among the three copolymers, with a open-circuit voltage (Voc) of 0.79 V and a power conversion efficiency (PCE) of 8.43%. Furthermore, polymer PB-BTPf containing fluorophenyl groups shows a higher Voc of 0.99 V due to its more low-lying highest occupied molecular orbital (HOMO) compared with other two structural polymeric analogues. The results here provide further fundamental insights into the relationship between the fluorination on electron-withdrawing moiety and the photovoltaic performance for the conjugated polymers applied in fullerene organic solar cells.
AB - Three new donor-acceptor (D-A) conjugated polymers based on benzo[1,2-b:4,5-b′]dithiophene (BDT) and benzo[c][1,2,5]thiadiazole (BT), namely, PB-BT, PB-BTf and PB-BTPf, were synthesized with different substituents (Hydrogen atoms, Fluorine atoms and fluorophenyl groups) on BT unit. Experimental results and theoretical calculations indicate that molecularly tuning of side chains on BT moeity simultaneously influences the energy levels and intermolecular packing of the resulted polymers by modulating their electron affinity and molecular coplanarity. The polymer solar cells (PSCs) based on a blend of PB-BTf/[6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) exhibits the best photovoltaic performance among the three copolymers, with a open-circuit voltage (Voc) of 0.79 V and a power conversion efficiency (PCE) of 8.43%. Furthermore, polymer PB-BTPf containing fluorophenyl groups shows a higher Voc of 0.99 V due to its more low-lying highest occupied molecular orbital (HOMO) compared with other two structural polymeric analogues. The results here provide further fundamental insights into the relationship between the fluorination on electron-withdrawing moiety and the photovoltaic performance for the conjugated polymers applied in fullerene organic solar cells.
KW - Benzothiadiazole
KW - Donor-acceptor
KW - Fluorination
KW - Polymer solar cells
KW - Steric hindrance
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U2 - 10.1016/j.solener.2021.03.030
DO - 10.1016/j.solener.2021.03.030
M3 - Article
AN - SCOPUS:85104304285
SN - 0038-092X
VL - 220
SP - 864
EP - 872
JO - Solar Energy
JF - Solar Energy
ER -
