title: Correlating Molecular Structures with Transport Dynamics in High-Efficiency Small-Molecule Organic Photovoltaics.
abstract: Efficient charge transport is a key step toward high efficiency in small-molecule organic photovoltaics. Here we applied time-of-flight and organic field-effect transistor to complementarily study the influences of molecular structure, trap states, and molecular orientation on charge transport of small-molecule DRCN7T (D1) and its analogue DERHD7T (D2). It is revealed that, despite the subtle difference of the chemical structures, D1 exhibits higher charge mobility, the absence of shallow traps, and better photosensitivity than D2. Moreover, charge transport is favored in the out-of-plane structure within D1-based organic solar cells, while D2 prefers in-plane charge transport.
authors.affiliation: †Department of Materials Science, Fudan University, Shanghai 200433, China.
authors.forename: Jiajun
authors.initials: J
authors.lastname: Peng
authors.affiliation: †Department of Materials Science, Fudan University, Shanghai 200433, China.
authors.forename: Yani
authors.initials: Y
authors.lastname: Chen
authors.affiliation: ‡School of Materials Science and Engineering, Tongji University, Shanghai 201804, China.
authors.forename: Xiaohan
authors.initials: X
authors.lastname: Wu
authors.affiliation: §Key Laboratory for Functional Polymer Materials and Centre for Nanoscale Science and Technology, Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: §Key Laboratory for Functional Polymer Materials and Centre for Nanoscale Science and Technology, Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Kan
authors.affiliation: †Department of Materials Science, Fudan University, Shanghai 200433, China.
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Chen
authors.affiliation: §Key Laboratory for Functional Polymer Materials and Centre for Nanoscale Science and Technology, Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Chen
authors.affiliation: ‡School of Materials Science and Engineering, Tongji University, Shanghai 201804, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Huang
authors.affiliation: †Department of Materials Science, Fudan University, Shanghai 200433, China.
authors.forename: Ziqi
authors.initials: Z
authors.lastname: Liang
keywords: charge mobility; organic field-effect transistor; organic photovoltaics; time-of-flight; transport dynamics; π-conjugated small molecules