Pyrene-cored dendrimer with carbazole derivatives as dendrons: synthesis, properties and application in white light-emitting diode

Abstract

A new dendrimer using pyrene as core and carbazole derivative as dendron has been successfully prepared via Suzuki coupling reaction. Its chemical structure was confirmed through ¹H NMR, elemental analysis and MALDI-TOF MS methods. The dendrimer synthesized possessed excellent thermal stability with initial decomposition temperature over 470 °C and high fluorescence quantum yield of 86%. The luminescence spectra showed that, relative to the solution sample, the emission peaks of the solid dendrimer film were apparently broadened and red-shifted, indicating the strong π–π stacking effect between the pyrene moieties. By doping 1.5% of the dendrimer in 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB), a light-emitting diode device was fabricated in the ITO/NPB/NPB : dendrimer (1.5%)/TPBI/Mg : Ag configuration, which emitted a white color with Commission Internationale de L'Eclairage (CIE_x,y) coordinates of (0.29, 0.34) and a maximum brightness of 1300 cd m⁻², exhibiting promising potential in white light-emitting diode application.