TY - JOUR
T1 - Developing Wide Bandgap Polymers Based on Sole Benzodithiophene Units for Efficient Polymer Solar Cells
AU - Xu, Xiaopeng
AU - Lee, Young Woong
AU - Woo, Han Young
AU - Li, Ying
AU - Peng, Qiang
N1 - Funding Information:
This study was supported by the National Natural Science Foundation of China (NSFC) (21825502, 51573107, 91633301 and 21432005) and the Foundation of State Key Laboratory of Polymer Materials Engineering (SKLPME 2017‐2‐04).
Publisher Copyright:
© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2020/9/1
Y1 - 2020/9/1
N2 - In this work, a series of sole benzodithiophene-based wide band gap polymer donors, namely PBDTT, PBDTS, PBDTF and PBDTCl, were developed for efficient polymer solar cells (PSCs) by varying the heteroatoms into the conjugated side chains. The effects of sulfuration, fluorination and chlorination were also investigated systematically on the overall properties of these BDT-based polymers. The HOMO levels could be lowered gradually by introducing sulfur, fluorine and chlorine atoms into the side chains, which contributed to the stepwise increased Voc (from 0.78 V to 0.84 V) in the related PSCs using Y6 as the electron acceptor. This side-chain engineering strategy could promote the polymer chain interactions and fine-tune the phase separation of active blends, leading to enhanced absorption, ordered molecular packing and crystallinity. Among them, the chlorinated PBDTCl exhibited not only high level absorption and crystallinity, but also the most balanced hole/electron charge transport and the most optimized morphology, giving rise to the best PCE of 13.46 % with a Voc of 0.84 V, a Jsc of 23.16 mA cm−2 and an FF of 69.2 %. The chlorination strategy afforded PBDTCl synthetic simplicity but high efficiency, showing its promising photovoltaic applications for realizing low-cost practical PSCs in near future.
AB - In this work, a series of sole benzodithiophene-based wide band gap polymer donors, namely PBDTT, PBDTS, PBDTF and PBDTCl, were developed for efficient polymer solar cells (PSCs) by varying the heteroatoms into the conjugated side chains. The effects of sulfuration, fluorination and chlorination were also investigated systematically on the overall properties of these BDT-based polymers. The HOMO levels could be lowered gradually by introducing sulfur, fluorine and chlorine atoms into the side chains, which contributed to the stepwise increased Voc (from 0.78 V to 0.84 V) in the related PSCs using Y6 as the electron acceptor. This side-chain engineering strategy could promote the polymer chain interactions and fine-tune the phase separation of active blends, leading to enhanced absorption, ordered molecular packing and crystallinity. Among them, the chlorinated PBDTCl exhibited not only high level absorption and crystallinity, but also the most balanced hole/electron charge transport and the most optimized morphology, giving rise to the best PCE of 13.46 % with a Voc of 0.84 V, a Jsc of 23.16 mA cm−2 and an FF of 69.2 %. The chlorination strategy afforded PBDTCl synthetic simplicity but high efficiency, showing its promising photovoltaic applications for realizing low-cost practical PSCs in near future.
KW - energy conversion
KW - photovoltaics
KW - polymer solar cells
KW - sole donor unit
KW - synthetic simplicity
UR - http://www.scopus.com/inward/record.url?scp=85083440543&partnerID=8YFLogxK
U2 - 10.1002/chem.202000951
DO - 10.1002/chem.202000951
M3 - Article
C2 - 32227512
AN - SCOPUS:85083440543
SN - 0947-6539
VL - 26
SP - 11241
EP - 11249
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 49
ER -
