title: Side-chain Engineering of Benzo[1,2-b:4,5-b']dithiophene Core-structured Small Molecules for High-Performance Organic Solar Cells.
abstract: Three novel small molecules have been developed by side-chain engineering on benzo[1,2-b:4,5-b']dithiophene (BDT) core. The typical acceptor-donor-acceptor (A-D-A) structure is adopted with 4,8-functionalized BDT moieties as core, dioctylterthiophene as π bridge and 3-ethylrhodanine as electron-withdrawing end group. Side-chain engineering on BDT core exhibits small but measurable effect on the optoelectronic properties of small molecules. Theoretical simulation and X-ray diffraction study reveal the subtle tuning of interchain distance between conjugated backbones has large effect on the charge transport and thus the photovoltaic performance of these molecules. Bulk-heterojunction solar cells fabricated with a configuration of ITO/PEDOT:PSS/SM:PC71BM/PFN/Al exhibit a highest power conversion efficiency (PCE) of 6.99% after solvent vapor annealing.
authors.affiliation: Key Laboratory of Soft Chemistry and Functional Materials (Ministry of Education of China), Nanjing University of Science and Technology, Nanjing, 210094, China.
authors.forename: Xinxing
authors.initials: X
authors.lastname: Yin
authors.affiliation: Key Laboratory of Luminescence and Optical Information (Ministry of Education of China), Beijing Jiaotong University, Beijing, 100044, China.
authors.forename: Qiaoshi
authors.initials: Q
authors.lastname: An
authors.affiliation: Key Laboratory of Soft Chemistry and Functional Materials (Ministry of Education of China), Nanjing University of Science and Technology, Nanjing, 210094, China.
authors.forename: Jiangsheng
authors.initials: J
authors.lastname: Yu
authors.affiliation: Key Laboratory for Organic Electronics and Information Displays (KLOEID) and Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing 210046, China.
authors.forename: Fengning
authors.initials: F
authors.lastname: Guo
authors.affiliation: Key Laboratory of Soft Chemistry and Functional Materials (Ministry of Education of China), Nanjing University of Science and Technology, Nanjing, 210094, China.
authors.forename: Yongliang
authors.initials: Y
authors.lastname: Geng
authors.affiliation: Key Laboratory for Organic Electronics and Information Displays (KLOEID) and Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing 210046, China.
authors.forename: Linyi
authors.initials: L
authors.lastname: Bian
authors.affiliation: Key Laboratory of Soft Chemistry and Functional Materials (Ministry of Education of China), Nanjing University of Science and Technology, Nanjing, 210094, China.
authors.forename: Zhongsheng
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Key Laboratory of Soft Chemistry and Functional Materials (Ministry of Education of China), Nanjing University of Science and Technology, Nanjing, 210094, China.
authors.forename: Baojing
authors.initials: B
authors.lastname: Zhou
authors.affiliation: Key Laboratory for Organic Electronics and Information Displays (KLOEID) and Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing 210046, China.
authors.forename: Linghai
authors.initials: L
authors.lastname: Xie
authors.affiliation: Key Laboratory of Luminescence and Optical Information (Ministry of Education of China), Beijing Jiaotong University, Beijing, 100044, China.
authors.forename: Fujun
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Soft Chemistry and Functional Materials (Ministry of Education of China), Nanjing University of Science and Technology, Nanjing, 210094, China.
authors.forename: Weihua
authors.initials: W
authors.lastname: Tang