Facile synthesis of annulated benzothiadiazole derivatives and their application as medium band gap acceptors in organic photovoltaic devices. Issue 24 (8th June 2022)

• Record Type: Journal Article
• Authors: Hu, Xiantao; Datt, Ram; He, Qiao; Kafourou, Panagiota; Ka Hin Lee, Harrison; White, Andrew J. P.; Tsoi, Wing Chung; Heeney, Martin
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 24(2022)
• Page Start: 9249
• Page End: 9256
• Publication Date: 2022-06-08
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2tc01433e
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Two benzothiadiazole derivatives annulated with 2-(1, 3-dithiol-2-ylidene)malonitrile in the 4, 5-position were prepared by a one-step procedure, and investigated as end-groups in non-fullerene acceptors for indoor photovoltaic applications. Abstract : Two 2, 1, 3-benzothiadiazole derivatives annulated with 2-(1, 3-dithiol-2-ylidene)malonitrile in the 4, 5-positions were prepared by nucleophilic substitution reactions of a fluorinated precursor. The resulting derivatives were coupled to an electron rich indacenodithiophene core to afford two new non-fullerene acceptors (NFAs). Both NFAs exhibited identical absorption spectra in solution, but significant differences in the solid state as a result of the end group fluorination. Both materials performed as electron acceptors in solar cell blends with donor polymers. The resulting devices exhibited high open circuit voltages over 1 V under 1 sun illumination, as a result of their high lying LUMO levels. Devices based on the fluorinated acceptor demonstrated reasonable performance under low light conditions, with power conversion efficiencies up to 13.7%.