Kim Hee Su, Rasool Shafket, Shin Won Suk, Song Chang Eun, Hwang Do-Hoon
Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Busan 46241, Republic of Korea.
Energy Materials Research Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34114, Republic of Korea.
ACS Appl Mater Interfaces. 2020 Nov 11;12(45):50638-50647. doi: 10.1021/acsami.0c13277. Epub 2020 Oct 27.
In this work, a series of A-D-A'-D-A-type electron acceptors based on alkylated indacenodithiophene (C8IDT), dicyanated thiophene-flanked 2,1,3-benzothiadiazole (CNDTBT), and 2-(3-oxo-2,3-dihydro-1-inden-1-ylidene)malononitrile (INCN) or 2-(5,6-difluoro-3-oxo-2,3-dihydro-1-inden-1-ylidene) malononitrile (FINCN) are synthesized in order to investigate the effect of substituents on their photovoltaic properties. The corresponding CNDTBT-C8IDT-INCN and CNDTBT-C8IDT-FINCN acceptors vary in their optical, electrochemical, morphological, and charge transport properties. The fluorinated-INCN-based acceptor (CNDTBT-C8IDT-FINCN) exhibits lower energy levels, improved absorptivity, narrower π-π spacing, and prominent fibrillar structures when it is blended with poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)-benzo[1,2-:4,5-']dithiophene))--5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo [1',2'-:4',5'-']dithiophene-4,8-dione)] (PBDB-T). CNDTBT-C8IDT-FINCN exhibits a high power conversion efficiency (PCE) of 12.33% due to its high and well-balanced charge carrier mobility and distinct face-on orientation. Furthermore, large-area organic solar cells (OSCs) (active area: 55.45 cm) with CNDTBT-C8IDT-FINCN exhibit a high PCE of 9.21%. This result demonstrates that CNDTBT-C8IDT-FINCN is a suitable and promising electron acceptor for large-area OSCs.
在本工作中，合成了一系列基于烷基化茚并二噻吩（C8IDT）、二氰基噻吩桥连的2,1,3-苯并噻二唑（CNDTBT）以及2-(3-氧代-2,3-二氢-1-茚亚基)丙二腈（INCN）或2-(5,6-二氟-3-氧代-2,3-二氢-1-茚亚基)丙二腈（FINCN）的A-D-A'-D-A型电子受体，以研究取代基对其光伏性能的影响。相应的CNDTBT-C8IDT-INCN和CNDTBT-C8IDT-FINCN受体在光学、电化学、形态和电荷传输性能方面存在差异。当基于氟化-INCN的受体（CNDTBT-C8IDT-FINCN）与聚[(2,6-(4,8-双(5-(2-乙基己基)噻吩-2-基)-苯并[1,2-:4,5-']二噻吩))--5,5-(1',3'-二-2-噻吩基-5',7'-双(2-乙基己基)苯并[1',2'-:4',5'-']二噻吩-4,8-二酮)]（PBDB-T）共混时，表现出较低的能级、提高的吸收率、更窄的π-π间距以及显著的纤维状结构。由于其高且平衡的电荷载流子迁移率和明显的面取向，CNDTBT-C8IDT-FINCN表现出12.33%的高功率转换效率（PCE）。此外，具有CNDTBT-C8IDT-FINCN的大面积有机太阳能电池（OSC）（活性面积：55.45平方厘米）表现出9.21%的高PCE。该结果表明CNDTBT-C8IDT-FINCN是用于大面积OSC的合适且有前景的电子受体。
