Synthesis and luminescent properties of novel organic luminescent materials based on carbazole derivatives

摘要

Four novel host materials C1-C4 based on carbazole derivatives have been designed, synthesized, characterized, and applied as organic light-emitting devices. This report presents a novel approach, which combines carbazole and aromatic hydrocarbons through methylene. The formed molecules exhibited twisted structures, which resulted in high glass transition temperatures (T (g)), ranged from 90.4 to 148.0 A degrees C. They also had high optical bandgaps (E (g)), their optical energy bandgaps are determined by absorption edge technique as 3.22 to 3.50 eV, evaluated photo-physical properties of these synthesized novel chromophores, the optical properties such as maximum absorption and emission wavelengths (lambda, nm), molar extinction coefficients (epsilon, cm(- 1) M- 1), Stoke's shifts (Delta lambda (ST), nm), and quantum yields (phi (F)) also studied the effect of solvent polarity on absorption and emission of these carbazole derivatives, and these compounds exhibited intense absorption bonds between 250 and 325 nm, which are attributed to the pi-pi* transition of the carbazole-centered units. In addition, they showed blue fluorescence in different solvents. These compounds showed bathochromic shift with the increase in the solvent polarity.