New Anthracene-Fused Nonfullerene Acceptors for High-Efficiency Organic Solar Cells: Energy Level Modulations Enabling Match of Donor and Acceptor

Feng, HR (Feng, Huanran)^[ 1,2,3 ] ; Yi, YQQ (Yi, Yuan-Qiu-Qiang)^[ 1,2,3 ] ; Ke, X (Ke, Xin)^[ 1,2,3 ] ; Yan, J (Yan, Jing)^[ 1,2,3 ] ; Zhang, YM (Zhang, Yamin)^[ 1,2,3 ] ; Wan, XJ (Wan, Xiangjian)^[ 1,2,3 ] ; Li, CX (Li, Chenxi)^[ 1,2,3 ] ; Zheng, N (Zheng, Nan)^[ 4 ] ; Xie, ZQ (Xie, Zengqi)^[ 4 ] ; Chen, YS (Chen, Yongsheng)^[ 1,2,3 ]

ADVANCED ENERGY MATERIALS, 2019, 9(12): 文献号: 1803541

DOI: 10.1002/aenm.201803541

Abstract

Two new nonfullerene small molecule acceptors (NF-SMAs) AT-NC and AT-4Cl based on heptacyclic anthracene(cyclopentadithiophene) (AT) core and different electron-withdrawing end groups are designed and synthesized. Although the two new acceptor molecules use two different end groups, naphthyl-fused indanone (NINCN) and chlorinated INCN (INCN-2Cl) demonstrate similar light absorption. AT-4Cl with chlorinated INCN as end groups are shifted significantly due to the strong electron-withdrawing ability of chlorine atoms. Thus, desirable V-oc, and photovoltaic performance are expected to be achieved when polymer PBDB-T is used as the electron donor with AT-NC as the acceptor, and fluorinated analog PBDB-TF with down-shifted energy levels is selected to blend with AT-4Cl. Consequently, the device based on P6DB-TF:AT-4Cl yields a high power conversion efficiency of 13.27% with a slightly lower V-oc of 0.901 V, significantly enhanced J(sc) of 19.52 mA cm(-2) and fill factor of 75.5% relative to the values based on PBDB-T:AT-NC. These results demonstrate that the use of a new electron-rich AT core, together with energy levels modulations by end-group optimizations enabling the match with polymer donors, is a successful strategy to construct high-performance NF-SMAs.