Multifunctional derivatives of donor-substituted perfluorobiphenyl for OLEDs and optical oxygen sensors. (September 2021)

• Record Type: Journal Article
• Authors: Danyliv, Iryna; Danyliv, Yan; Lytvyn, Roman; Bezvikonnyi, Oleksandr; Volyniuk, Dmytro; Simokaitiene, Jurate; Ivaniuk, Khrystyna; Tsiko, Uliana; Tomkeviciene, Ausra; Dabulienė, Asta; Skuodis, Eigirdas; Stakhira, Pavlo; Grazulevicius, Juozas Vidas
• Is Part Of: Dyes and pigments. Volume 193(2021)
• Publication Date: 2021-09
• Subjects: Perfluorobiphenyl -- Carbazole -- Diphenylamine -- TADF -- OLED -- Optical sensor; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2021.109493
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: New donor-acceptor and donor-acceptor-donor compounds based on perfluorobiphenyl electron acceptor and diphenylamine or carbazole as electron-donating units were designed, synthesized and characterized. The influence of the nature and number of electron-donating units on thermal, electrochemical and photophysical properties was studied. The compounds exhibited photoluminescence ranging from near-UV to green region. The solid samples of the compounds demonstrated photoluminescence quantum yields in the range from 0.1 to 0.51.2, 7-Dimethoxycarbazole-containing compound was characterized by negligible energy gaps between the lowest singlet and triplet states (0.1 eV) and subsequently showed thermally activated delayed fluorescence (TADF). Carbazolyl-substituted perfluorobiphenyl derivatives showed aggregation-induced emission enhancement and high values of the energies of triplet levels (up to 3.08 eV). The derivatives exhibited from moderate to high temperatures of 5% weight loss up to 356 °C. Electron mobility up to 1.2 × 10 −4 cm 2 V −1 s −1 at electric field of 7 × 10 5 V/cm was detected for the studied compounds by time-of-flight measurements. One compound with the best combination of the required properties for the OLED hosts was selected for the fabrication of green TADF-based OLED. The device showed maximum external quantum efficiency of 15.1%. Another compound exhibiting efficient TADF demonstrated oxygen sensitivity with non-linear Stern-Volmer curve which was well fitted by two Stern-Volmer constants of 6.54·10 −4 and 7.17·10 −6 ppm −1 . Graphical abstract: Image 1 Highlights: Simple and inexpensive one-step synthesis of the perfluorobiphenyl-based multifunctional semiconductors. Disubstituted carbazole-perfluorobiphenyl material was used as host for fabrication of TADF OLED with maximum EQE of 15.1%. The material which exhibited TADF was used in oxygen sensor with Stern-Volmer constants of 6.54·10 −4 and of 7.17·10 −6 ppm −1 .