TY - JOUR
T1 - A New Wide Bandgap Donor Polymer for Efficient Nonfullerene Organic Solar Cells with a Large Open-Circuit Voltage
AU - Tang, Yumin
AU - Sun, Huiliang
AU - Wu, Ziang
AU - Zhang, Yujie
AU - Zhang, Guangye
AU - Su, Mengyao
AU - Zhou, Xin
AU - Wu, Xia
AU - Sun, Weipeng
AU - Zhang, Xianhe
AU - Liu, Bin
AU - Chen, Wei
AU - Liao, Qiaogan
AU - Woo, Han Young
AU - Guo, Xugang
N1 - Funding Information:
Y.T. and H.S. contributed equally to this work. The authors thank National Natural Science Foundation of China (21801124 and 51573076) and Shenzhen Basic Research Fund (JCYJ20170817105905899 and JCYJ20180504165709042). H.Y.W. is grateful to the financial support from the National Research Foundation of Korea (2016M1A2A2940911 and 2015M1A2A2057506).
Publisher Copyright:
© 2019 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2019/11/1
Y1 - 2019/11/1
N2 - Significant progress has been made in nonfullerene small molecule acceptors (NF-SMAs) that leads to a consistent increase of power conversion efficiency (PCE) of nonfullerene organic solar cells (NF-OSCs). To achieve better compatibility with high-performance NF-SMAs, the direction of molecular design for donor polymers is toward wide bandgap (WBG), tailored properties, and preferentially ecofriendly processability for device fabrication. Here, a weak acceptor unit, methyl 2,5-dibromo-4-fluorothiophene-3-carboxylate (FE-T), is synthesized and copolymerized with benzo[1,2-b:4,5-b′]dithiophene (BDT) to afford a series of nonhalogenated solvent processable WBG polymers P1-P3 with a distinct side chain on FE-T. The incorporation of FE-T leads to polymers with a deep highest occupied molecular orbital (HOMO) level of −5.60−5.70 eV, a complementary absorption to NF-SMAs, and a planar molecular conformation. When combined with the narrow bandgap acceptor ITIC-Th, the solar cell based on P1 with the shortest methyl chain on FE-T achieves a PCE of 11.39% with a large Voc of 1.01 V and a Jsc of 17.89 mA cm−2. Moreover, a PCE of 12.11% is attained for ternary cells based on WBG P1, narrow bandgap PTB7-Th, and acceptor IEICO-4F. These results demonstrate that the new FE-T is a highly promising acceptor unit to construct WBG polymers for efficient NF-OSCs.
AB - Significant progress has been made in nonfullerene small molecule acceptors (NF-SMAs) that leads to a consistent increase of power conversion efficiency (PCE) of nonfullerene organic solar cells (NF-OSCs). To achieve better compatibility with high-performance NF-SMAs, the direction of molecular design for donor polymers is toward wide bandgap (WBG), tailored properties, and preferentially ecofriendly processability for device fabrication. Here, a weak acceptor unit, methyl 2,5-dibromo-4-fluorothiophene-3-carboxylate (FE-T), is synthesized and copolymerized with benzo[1,2-b:4,5-b′]dithiophene (BDT) to afford a series of nonhalogenated solvent processable WBG polymers P1-P3 with a distinct side chain on FE-T. The incorporation of FE-T leads to polymers with a deep highest occupied molecular orbital (HOMO) level of −5.60−5.70 eV, a complementary absorption to NF-SMAs, and a planar molecular conformation. When combined with the narrow bandgap acceptor ITIC-Th, the solar cell based on P1 with the shortest methyl chain on FE-T achieves a PCE of 11.39% with a large Voc of 1.01 V and a Jsc of 17.89 mA cm−2. Moreover, a PCE of 12.11% is attained for ternary cells based on WBG P1, narrow bandgap PTB7-Th, and acceptor IEICO-4F. These results demonstrate that the new FE-T is a highly promising acceptor unit to construct WBG polymers for efficient NF-OSCs.
KW - complementary absorption
KW - donor polymers
KW - nonfullerene organic solar cells
KW - nonhalogenated solvents
KW - wide bandgap
UR - http://www.scopus.com/inward/record.url?scp=85071395401&partnerID=8YFLogxK
U2 - 10.1002/advs.201901773
DO - 10.1002/advs.201901773
M3 - Article
AN - SCOPUS:85071395401
SN - 2198-3844
VL - 6
JO - Advanced Science
JF - Advanced Science
IS - 21
M1 - 1901773
ER -