title: Efficient Nonfullerene Polymer Solar Cells Enabled by a Novel Wide Bandgap Small Molecular Acceptor.
abstract: A wide bandgap small molecular acceptor, SFBRCN, containing a 3D spirobifluorene core flaked with a 2,1,3-benzothiadiazole (BT) and end-capped with highly electron-deficient (3-ethylhexyl-4-oxothiazolidine-2-yl)dimalononitrile (RCN) units, has been successfully synthesized as a small molecular acceptor (SMA) for nonfullerene polymer solar cells (PSCs). This SMA exhibits a relatively wide optical bandgap of 2.03 eV, which provides a complementary absorption to commonly used low bandgap donor polymers, such as PTB7-Th. The strong electron-deficient BT and RCN units afford SFBRCN with a low-lying LUMO (lowest unoccupied molecular orbital) level, while the 3D structured spirobifluorene core can effectively suppress the self-aggregation tendency of the SMA, thus yielding a polymer:SMA blend with reasonably small domain size. As the results of such molecular design, SFBRCN enables nonfullerene PSCs with a high efficiency of 10.26%, which is the highest performance reported to date for a large bandgap nonfullerene SMA.
authors.affiliation: Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, and State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610064, P. R. China.
authors.forename: Guangjun
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Department of Chemistry and Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, 999077, Hong Kong SAR.
authors.forename: Guofang
authors.initials: G
authors.lastname: Yang
authors.affiliation: Department of Chemistry and Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, 999077, Hong Kong SAR.
authors.forename: He
authors.initials: H
authors.lastname: Yan
authors.affiliation: Department of Physics, North Carolina State University, Raleigh, NC, 27695, USA.
authors.forename: Joo-Hyun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Physics, North Carolina State University, Raleigh, NC, 27695, USA.
authors.forename: Harald
authors.initials: H
authors.lastname: Ade
authors.affiliation: Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, and State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610064, P. R. China.
authors.forename: Wenlin
authors.initials: W
authors.lastname: Wu
authors.affiliation: Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, and State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610064, P. R. China.
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Xu
authors.affiliation: Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, and State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610064, P. R. China.
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Duan
authors.affiliation: Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, and State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610064, P. R. China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Peng
keywords: complementary absorption; high efficiency; nonfullerene acceptors; polymer solar cells; wide bandgap