TY - JOUR
T1 - Regioisomeric Polymer Semiconductors Based on Cyano-Functionalized Dialkoxybithiophenes
T2 - Structure–Property Relationship and Photovoltaic Performance
AU - Bai, Qingqing
AU - Huang, Jun
AU - Guo, Han
AU - Ma, Suxiang
AU - Yang, Jie
AU - Liu, Bin
AU - Yang, Kun
AU - Sun, Huiliang
AU - Woo, Han Young
AU - Niu, Li
AU - Guo, Xugang
N1 - Funding Information:
This work is supported by the National Natural Science Foundation of China (Nos. 52173172, 52173171, and 21801124), the Natural Science Foundation for Distinguished Young Scholars of Guangdong Province (2021B1515020027), Guangdong Basic and Applied Basic Research Foundation (2021A1515110892), China Postdoctoral Science Foundation (2021M700062), the Shenzhen Science and Technology Innovation Commission (JCYJ202103243104813035 and JCYJ20180504165709042), and the Open Fund of the State Key Laboratory of Luminescent Materials and Devices (South China University of Technology). X.G. is thankful for the financial support from the Songshan Lake Materials Laboratory (2021SLABFK03). HYW is grateful for the financial support from the NRF of Korea (2016M1A2A2940911, 2017K2A9A2A12000315). Our work was also supported by the Center for Computational Science and Engineering of Southern University of Science and Technology.
Publisher Copyright:
© 2022, The Author(s).
PY - 2022/10
Y1 - 2022/10
N2 - Cyano substitution is vital to the molecular design of polymer semiconductors toward highly efficient organic solar cells. However, how regioselectivity impacts relevant optoelectronic properties in cyano-substituted bithiophene systems remain poorly understood. Three regioisomeric cyano-functionalized dialkoxybithiophenes BTHH, BTHT, and BTTT with head-to-head, head-to-tail, and tail-to-tail linkage, respectively, were synthesized and characterized in this work. The resulting polymer semiconductors (PBDTBTs) based on these building blocks were prepared accordingly. The regiochemistry and property relationships of PBDTBTs were investigated in detail. The BTHH moiety has a higher torsional barrier than the analogs BTHT and BTTT, and the regiochemistry of dialkoxybithiophenes leads to fine modulation in the optoelectronic properties of these polymers, such as optical absorption, band gap, and energy levels of frontier molecular orbitals. Organic field-effect transistors based on PBDTBTHH had higher hole mobility (4.4 × 10−3 cm2/(V·s)) than those (ca. 10−4 cm2/(V·s)) of the other two polymer analogs. Significantly different short-circuit current densities and fill factors were obtained in polymer solar cells using PBDTBTs as the electron donors. Such difference was probed in greater detail by performing space-charge-limited current mobility, thin-film morphology, and transient photocurrent/photovoltage characterizations. The findings highlight that the BTHH unit is a promising building block for the construction of polymer donors for high-performance organic photovoltaic cells. Graphical abstract: [Figure not available: see fulltext.].
AB - Cyano substitution is vital to the molecular design of polymer semiconductors toward highly efficient organic solar cells. However, how regioselectivity impacts relevant optoelectronic properties in cyano-substituted bithiophene systems remain poorly understood. Three regioisomeric cyano-functionalized dialkoxybithiophenes BTHH, BTHT, and BTTT with head-to-head, head-to-tail, and tail-to-tail linkage, respectively, were synthesized and characterized in this work. The resulting polymer semiconductors (PBDTBTs) based on these building blocks were prepared accordingly. The regiochemistry and property relationships of PBDTBTs were investigated in detail. The BTHH moiety has a higher torsional barrier than the analogs BTHT and BTTT, and the regiochemistry of dialkoxybithiophenes leads to fine modulation in the optoelectronic properties of these polymers, such as optical absorption, band gap, and energy levels of frontier molecular orbitals. Organic field-effect transistors based on PBDTBTHH had higher hole mobility (4.4 × 10−3 cm2/(V·s)) than those (ca. 10−4 cm2/(V·s)) of the other two polymer analogs. Significantly different short-circuit current densities and fill factors were obtained in polymer solar cells using PBDTBTs as the electron donors. Such difference was probed in greater detail by performing space-charge-limited current mobility, thin-film morphology, and transient photocurrent/photovoltage characterizations. The findings highlight that the BTHH unit is a promising building block for the construction of polymer donors for high-performance organic photovoltaic cells. Graphical abstract: [Figure not available: see fulltext.].
KW - Cyano substitution
KW - Mobility
KW - Organic photovoltaic cells
KW - Polymer semiconductors
KW - Regioselectivity
UR - http://www.scopus.com/inward/record.url?scp=85133925658&partnerID=8YFLogxK
U2 - 10.1007/s12209-022-00323-0
DO - 10.1007/s12209-022-00323-0
M3 - Article
AN - SCOPUS:85133925658
SN - 1006-4982
VL - 28
SP - 385
EP - 397
JO - Transactions of Tianjin University
JF - Transactions of Tianjin University
IS - 5
ER -