TY - JOUR

T1 - Selectively Fluorinated Furan-Phenylene Co-Oligomers Pave the Way to Bright Ambipolar Light-Emitting Electronic Devices

AU - Koskin, Igor P.

AU - Becker, Christina S.

AU - Sonina, Alina A.

AU - Trukhanov, Vasiliy A.

AU - Shumilov, Nikita A.

AU - Kuimov, Anatoly D.

AU - Zhuravleva, Yuliya S.

AU - Kiseleva, Yuliya O.

AU - Shundrina, Inna K.

AU - Sherin, Peter S.

AU - Paraschuk, Dmitry Yu

AU - Kazantsev, Maxim S.

N1 - Funding Information: The work on materials synthesis, characterizations, X‐ray study, quantum chemical calculations, optical spectroscopy measurements in solutions and crystals, and single‐crystal OFET study was supported by RSF project #20‐73‐10090 and was performed in the N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry. The work on thin film OFETs and OLETs was supported by RSF project #18‐12‐00499 and was performed in the Institute of Synthetic Polymeric Matserials. The characterization of thin films was conducted using the equipment purchased under the Lomonosov Moscow State University Program of Development. The study of optical properties of solid solutions and aggregates was supported by the State Assignment of Ministry of Science and Higher Education of Russian Federation, project #0238‐2019‐0004 and was performed in N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry. The authors acknowledge Multi‐Access Chemical Service Center SB RAS for spectral and analytical measurements, Ministry of Science and Higher Education of Russian Federation for the access to the time‐resolved fluorescent equipment, Siberian Supercomputing Center ( http://www2.sscc.ru/ ) for computational resources. Publisher Copyright: © 2021 Wiley-VCH GmbH

PY - 2021/11/25

Y1 - 2021/11/25

N2 - Linearly conjugated oligomers attract ever-growing attention as promising systems for organic optoelectronics because of their inherent lucky combination of high charge mobility and bright luminescence. Among them, furan-phenylene co-oligomers (FPCOs) are distinguished by outstanding solubility, very bright luminescence, and good hole-transport properties; however, furan-containing organic semiconductors generally lack electron transport, which makes it impossible to utilize them in efficient light-emitting electronic devices, specifically, ambipolar light-emitting transistors. In this work, 1,4-bis(5-phenylfuran-2-yl)benzene (FP5) derivatives are synthesized with the fully/partially fluorinated central and edge phenyl rings. It is shown that the selective fluorination of FPCOs lowers the energies of frontier molecular orbitals, maintaining the bandgap, solubility, and bright luminescence, dramatically improves the photostability, tunes the π-π stacked packing, and allows the first realization of electron transport in FPCOs. It is found that selectively fluorinated 2,2′-(2,3,5,6-tetrafluoro-1,4-phenylene)bis[5-(3,5-difluorophenyl)furan] demonstrates well-balanced ambipolar charge transport and efficient electroluminescence in an organic light-emitting transistor (OLET) with external quantum and luminous efficiencies as high as 0.63% and 5 cdA−1, respectively, which are among the best reported for OLETs. The findings show that “smart” fluorination is a powerful tool to fine-tune the stability and performance of linearly conjugated small molecules for organic optoelectronics.

AB - Linearly conjugated oligomers attract ever-growing attention as promising systems for organic optoelectronics because of their inherent lucky combination of high charge mobility and bright luminescence. Among them, furan-phenylene co-oligomers (FPCOs) are distinguished by outstanding solubility, very bright luminescence, and good hole-transport properties; however, furan-containing organic semiconductors generally lack electron transport, which makes it impossible to utilize them in efficient light-emitting electronic devices, specifically, ambipolar light-emitting transistors. In this work, 1,4-bis(5-phenylfuran-2-yl)benzene (FP5) derivatives are synthesized with the fully/partially fluorinated central and edge phenyl rings. It is shown that the selective fluorination of FPCOs lowers the energies of frontier molecular orbitals, maintaining the bandgap, solubility, and bright luminescence, dramatically improves the photostability, tunes the π-π stacked packing, and allows the first realization of electron transport in FPCOs. It is found that selectively fluorinated 2,2′-(2,3,5,6-tetrafluoro-1,4-phenylene)bis[5-(3,5-difluorophenyl)furan] demonstrates well-balanced ambipolar charge transport and efficient electroluminescence in an organic light-emitting transistor (OLET) with external quantum and luminous efficiencies as high as 0.63% and 5 cdA−1, respectively, which are among the best reported for OLETs. The findings show that “smart” fluorination is a powerful tool to fine-tune the stability and performance of linearly conjugated small molecules for organic optoelectronics.

KW - ambipolar charge transport

KW - electroluminescence

KW - fluorination

KW - light-emitting transistor

KW - organic optoelectronics

UR - http://www.scopus.com/inward/record.url?scp=85113685531&partnerID=8YFLogxK

U2 - 10.1002/adfm.202104638

DO - 10.1002/adfm.202104638

M3 - Article

AN - SCOPUS:85113685531

VL - 31

JO - Advanced Functional Materials

JF - Advanced Functional Materials

SN - 1616-301X

IS - 48

M1 - 2104638

ER -