R. Pashazadeh “Synthesis and studies of multifunctional materials based on quinoxaline or pyridopyrazine as acceptor moieties” doctoral dissertation defence

Author, Institution: Ramin Pashazadeh, Kaunas University of Technology

Science area, field of science: Technological Sciences, Materials Engineering T 008

Dissertation was prepared externally.

Scientific Advisor: Prof. Dr. Habil. Juozas Vidas Gražulevičius (Kaunas University of Technology, Technological Sciences, Materials Engineering T 008).

Dissertation Defence Board of Material Engineering Science Field:
Prof. Dr. Jolita Ostrauskaitė (Kaunas University of Technology, Technological Sciences, Materials Engineering, T 008) – chairwoman;
Dr. Mindaugas Andrulevičius (Kaunas University of Technology, Technological Sciences, Materials Engineering, T 008);
Dr. Vladyslav Cherpak (University of Colorado, USA, Natural Sciences, Physics, N 002).
Prof. Dr. Saulius Grigalevičius (Kaunas University of Technology, Technological Sciences, Materials Engineering, T 008);
Prof. Dr. Edvinas Orentas (Vilnius University, Natural sciences, Chemistry, N 003);

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

Annotation:

In this work new series of multifunctional materials were synthesized and investigated. The presented compounds are comprised of quinoxaline/pyridopyrazine as the acceptor unit, and derivatives of carbazole and iminodibenzyl as the donor fragment. The studied compounds demonstrated thermally activated delayed fluorescence, mechanochromic luminescence and/or phosphorescence at room temperature. The study showed that derivatives of iminodibenzyl with quinoxaline having dual emission of delayed fluorescence and phosphorescence at room temperature. Meanwhile, application of external stimuli on the luminescence of materials and their response to environmental changes were described. In addition, derivatives of carbazole and quinoxaline were employed to fabricate efficient solution-processed OLED devices. The device containing 2,3-bis(3,6-dimethoxy-9H-carbazol-9-yl)quinoxaline, as an emitter showed the external quantum efficiency of 10.9% and luminance of  16760 cd m^-2.