Fused‐ring induced end‐on orientation in conjugated molecular dyads toward efficient single‐component organic solar cells
Dongdong Xia,
Shengxi Zhou,
Wen Liang Tan,
Safakath Karuthedath,
Chengyi Xiao,
Chaowei Zhao,
Frédéric Laquai,
Christopher R. McNeill,
Weiwei Li
Affiliations
Dongdong Xia
Institute of Applied Chemistry Jiangxi Academy of Sciences Nanchang China
Shengxi Zhou
Beijing Advanced Innovation Center for Soft Matter Science and Engineering & State Key Laboratory of Organic‐Inorganic Composites Beijing University of Chemical Technology Beijing China
Wen Liang Tan
Department of Materials Science and Engineering Monash University Clayton Australia
Safakath Karuthedath
KAUST Solar Center (KSC), Physical Sciences and Engineering Division (PSE) Material Science and Engineering Program (MSE) King Abdullah University of Science and Technology (KAUST) Thuwal Saudi Arabia
Chengyi Xiao
Beijing Advanced Innovation Center for Soft Matter Science and Engineering & State Key Laboratory of Organic‐Inorganic Composites Beijing University of Chemical Technology Beijing China
Chaowei Zhao
Institute of Applied Chemistry Jiangxi Academy of Sciences Nanchang China
Frédéric Laquai
KAUST Solar Center (KSC), Physical Sciences and Engineering Division (PSE) Material Science and Engineering Program (MSE) King Abdullah University of Science and Technology (KAUST) Thuwal Saudi Arabia
Christopher R. McNeill
Department of Materials Science and Engineering Monash University Clayton Australia
Weiwei Li
Beijing Advanced Innovation Center for Soft Matter Science and Engineering & State Key Laboratory of Organic‐Inorganic Composites Beijing University of Chemical Technology Beijing China
Abstract The molecular orientations of conjugated materials on the substrate mainly include edge‐on, face‐on, and end‐on. Edge‐on and face‐on orientations have been widely observed, while end‐on orientation has been rarely reported. Since in organic solar cells (OSCs) charge transport is along the vertical direction, end‐on orientation with conjugated backbones perpendicular to the substrate is recognized as the ideal microstructure for OSCs. In this work, we for the first time obtained the preferential end‐on orientation in a conjugated molecular dyad that contains a conjugated backbone as donor and perylene bisimide side units as acceptor. This was realized by introducing a fused‐ring structure to replace linear terthiophenes with conjugated backbones, yielding F‐MDPBI and L‐MDPBI respectively. Surprisingly, a shifting trend of the molecular orientation from dominating edge‐on in L‐MDPBI to preferential end‐on in F‐MDPBI was observed. As a consequence, vertical charge carrier mobilities in F‐MDPBI are one order of magnitude higher than those with preferential edge‐on orientation, so single‐component OSCs based on this molecular dyad as a single photoactive layer provided a power conversion efficiency of 4.89% compared to 1.70% based on L‐MDPBI with preferential edge‐on orientation.
