Synthesis and properties of indole-based electroactive compounds

Author, Institution: Rasa Keruckienė, Kaunas University of Technology

Science Area, Field of Science: Technological Sciences, Materials Engineering – 08T

Scientific supervisor: Prof. Dr. Habil . Juozas Vidas Gražulevičius (Kaunas University of Technology, Technological Sciences, Materials Engineering – 08T).

Dissertation Defence Board of Materials Engineering Science Field:

Prof. Dr. Saulius Grigalevičius (Kaunas University of Technology, Technological Sciences, Materials Engineering – 08T) – chairman,
Prof. Dr. Gintaras BUIKA (Kaunas University of Technology, Technological Sciences, Materials Engineering – 08T),
Dr. Šarūnas MEŠKINIS (Kaunas University of Technology, Technological Sciences, Materials Engineering – 08T),
Prof. Dr. Adam PRON (Warsaw University of Technology, Technological Sciences, Materials Engineering – 08T ),
Prof. Dr. Habil. Sigitas Tumkevičius (Vilnius University, Physical Sciences, Chemistry – 03P).

The doctoral dissertation is available at the library of Kaunas University of Technology (K. Donelaičio g. 20,Kaunas)

Annotation:

The demanding requirements for the organic light emitting diodes force to search for new advanced organic electroactive materials. Indole-based materials show promising properties for the fabrication of efficient light emitting diodes (OLEDs). Indole-derived compounds have good luminescent and hole-transporting properties. There are still few reports on the synthesis and studies of electroactive indole derivatives with reactive functional groups. The synthesis and studies of cross-linkable indole  derivatives can open new possibilities in the fabrication of stable and efficient OLEDs by wet technologies.
In this work, synthesis and properties of indole-based electroactive materials are presented. Simple and efficient synthetic methods were applied for the preparation of target compounds. Their thermal, optical, photophysical, electrochemical and photoelectrical properties were investigated by experimental and computational methods.
The derivatives of 2-phenylindole were used as hosts in green phosphorescenr OLEDs. Iridium complex tris[2-phenylpyridinato-C2,N]iridium(III) was used as emitter. The devices demonstrated practically pure emission of the used dopant, the relatively low values of the turn-on voltages of 3.7 and 3.1 V as well as the brightness reaching 5700 and 11900 cd/m2. Napthyl-susbtituted indolylbenzo[b]carbazole derivatives were used as emitters in non-doped blue OLEDs. The devices demonstrated low values of turn-on voltages of 3.4 and 3.6 V and very high brightness values reaching 17700 Cd/m²and external quantum efficiency of 3.4 %.