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Publication Type Scientific article indexed in SCOPUS or WOS database
Funding for basic activity EU Structural Funds
Defending: ,
Publication language English (en)
Title in original language 3,3'-Bicarbazole Structural Derivatives as Charge Transporting Materials for Use in OLED Devices
Field of research 1. Natural sciences
Sub-field of research 1.4 Chemical sciences
Authors Armands Rudušs
Kaspars Traskovskis
Elīna Otikova
Aivars Vembris
Raitis Grzibovskis
Marcis Lielbardis
Valdis Kokars
Keywords OLED, charge transport, 3,3′-bicarbazole, host materials, luminescence, thin films
Abstract In this study we report novel 3,3′-bicarbazole based charge transporting materials mainly designed for a use in systems containing phosphorescent iridium (III) complex emitters. A low-cost oxidative coupling reaction using FeCl 3 was employed in the synthesis of 3,3′-bicarbazole compounds. Different derivatives of 3,3′-bicarbazole with 4-ethoxyphenyl- and ethyl- substituents at 9,9′- positions and (2,2-diphenylhydrazono)methyl- and 4-(dimethylamino)styryl- substituents at 6,6′- positions were synthesized. Obtained (2,2-diphenylhydrazono)methyl- derivatives exhibit glass transition temperatures that are sufficient for applications in electronic devices. Thin amorphous films of good optical quality can be produced from synthesized materials using spin-coating method. The effect of (2,2-diphenylhydrazono)methyl- substituents at 6,6′- and 4-ethoxyphenyl- substituents at 9,9′- positions on the charge transport properties of the 3,3′-bicarbazole derivatives was investigated. With the introduction of both electron acceptor and donor moieties to 3,3′-bicarbazole structure material electron and hole drift mobilities reach approximately 1·10 -5 cm 2 /V·s. Molecule ionization (I f ) levels and electron affinity (EA f ) levels in thin films were determined using photoelectric effect experiment. Depending on the nature of substituents at 6,6′- and 9,9′- positions I f levels range from -5.19 to -5.13 eV and EA f levels are from -2.44 to -2.38 eV.
DOI: 10.1117/12.2306850
Hyperlink: http://spie.org/Publications/Proceedings/Paper/10.1117/12.2306850 
Reference Rudušs, A., Traskovskis, K., Otikova, E., Vembris, A., Grzibovskis, R., Lielbardis, M., Kokars, V. 3,3'-Bicarbazole Structural Derivatives as Charge Transporting Materials for Use in OLED Devices. Proceedings of SPIE, 2018, Vol.10687: Organic Electronics and Photonics: Fundamentals and Devices, pp.1068718-1-1068718-8. ISSN 0277-786X. e-ISSN 1996-756X. Available from: doi:10.1117/12.2306850
Additional information Citation count:
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ID 27460