Two new nonfused ring nonfullerene electron acceptors, NFAs, (dicarbazolyl)bis(2-(3-oxo-2,3-dihydro-1-inden-1-ylidene)malononitrile) () and -(2-(5,6-fluoro-3-oxo-2,3-dihydro-1-inden-1-ylidene)malononitrile) (), thus exhibiting an A-D-A motif, were synthesized and characterized. As thin films, they exhibit the lowest energy absorption signature near 540 nm, extending down to ∼700 nm. This band is due to an intramolecular charge transfer process from the (nonfused dicarbazoyl; ) moiety to the malononitrile-based units () based on density functional theory calculations (DFT), which are also corroborated by time-dependent DFT (TDDFT) computations. Both NFAs fluoresce in the near-IR region exhibiting a band maximum peaking near 750 nm with biphasic lifetimes in the 75-410 ps time scale. Electrochemical measurements permitted the determination of their HOMO (∼-5.7 eV) and LUMO (∼-4.0 eV) energies. The absorption bands are complementary to those of the commercial copolymer , which was used to prepare binary blends for photovoltaic cell performance assessments (ITO/PEDOT:PSS/active layer/PFN-Br/Ag). The power conversion efficiencies (PCE) are found to be 10.17% for / (short-circuit current = 15.87 mA cm; open-circuit voltage = 1.03 V; fill factor FF = 0.622) and 14.09% for / ( = 20.92 mA cm; = 0.965 V; FF = 0.698). The use of nonfused ring NFAs achieving such high performances is significant and reveals a path toward simpler NFAs for use in organic photovoltaics.
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http://dx.doi.org/10.1021/acsami.4c19947 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
Département de chimie, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada.
Acc Chem Res
December 2024
College of Textiles & Clothing, State Key Laboratory of Bio-fibers and Eco-textiles, Qingdao University, Qingdao 266071, China.
Angew Chem Int Ed Engl
November 2024
State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, China.
High dark current density (J) severely hinders further advancement of near-infrared organic photodetectors (NIR OPDs). Herein, we tackle this grand challenge by regulating molecular crystallinity and aggregation of fully non-fused ring electron acceptors (FNREAs). TBT-V-F, which features fluorinated terminals, notably demonstrates crystalline intensification and a higher prevalence predominance of J-aggregation compared to its chlorinated counterpart (TBT-V-Cl).
View Article and Find Full Text PDFSmall
December 2024
Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, P. R. China.
Low-cost photovoltaic materials and additive-free, non-halogenated solvent processing of photoactive layers are crucial for the large-scale commercial application of organic solar cells (OSCs). However, high-efficiency OSCs that possess all these advantages remain scarce due to the lack of insight into the structure-property relationship. In this work, three fully non-fused ring electron acceptors (NFREAs), DTB21, DTB22, and DTB23, are reported by utilizing a simplified 1,4-di(thiophen-2-yl)benzene (DTB) core with varied alkoxy chain lengths on the thiophene bridge.
View Article and Find Full Text PDFCurr Top Med Chem
October 2024
Department of Chemistry, Veer Narmad South Gujarat University, Surat-395007, Gujarat, India.
Non-fused pyrimidine scaffold is a significant component for designing new drugs. The review emphasizes the pharmacological importance of non-fused pyrimidine-containing moieties based on the broad spectrum of activities such as antiprotozoal, antibacterial, antimycobacterial, anticancer, anti-inflammatory activity, and CNS depressant. Pyrimidine derivatives are fascinating entities that display biological activities for the treatment of cancer.
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