Carbazole-fluorene copolymers with various substituents at the carbazole nitrogen: structure-properties relationship

0573524 - ÚMCH 2024 RIV CH eng J - Článek v odborném periodiku
Cimrová, Věra - Výprachtický, Drahomír - Růžička, Aleš - Pokorná, Veronika
Carbazole-fluorene copolymers with various substituents at the carbazole nitrogen: structure-properties relationship.
Polymers. Roč. 15, č. 13 (2023), č. článku 2932. E-ISSN 2073-4360
Grant CEP: GA ČR(CZ) GC20-15498J
Institucionální podpora: RVO:61389013
Klíčová slova: carbazole-fluorene copolymers * iridium complex * synthesis
Obor OECD: Polymer science
Impakt faktor: 5, rok: 2022
Způsob publikování: Open access
https://www.mdpi.com/2073-4360/15/13/2932

Carbazole derivatives, carbazole-containing polymers and iridium complexes are of interest due to many possible applications in photonics, electronics and biology, particularly as active or hole-transporting layers in organic as well as perovskite devices due to their interesting properties. Here, a series of carbazole-fluorene conjugated copolymers with various substituents at the N-carbazole position (2-methoxycarbonylethyl, 2-carboxyethyl, 2-ethylhexyl, and nonan-2,4-dionatoiridium(III)bis(2-phenylpyridine-N,C2′)-9-yl) was prepared by Suzuki coupling. Their photophysical, electrochemical and electroluminescence (EL) properties were studied. Effects of molecular weight and substituents attached to carbazole unit on their properties are reported. The carbazole-fluorene copolymers in dilute solutions exhibited intense photoluminescence (PL) emission in the blue spectral region with high PL quantum yields (78–87%) except for the copolymer with the iridium complex (23%). Similar PL spectra were observed in dilute solutions. More pronounced differences were found in thin film PL and EL properties due to excimer/aggregate formation. Light-emitting devices (LEDs) made of copolymers with 2-ethylhexyl as N-carbazole substituent exhibited efficient EL emission with the best performance and the lowest EL onset voltages (3–4 V), while the LEDs made of copolymers with other substituents were not as efficient, but showed anomalous behavior and memory effects in current-voltage characteristics promising also for bio-inspired electronics.

Trvalý link: https://hdl.handle.net/11104/0344290