Synthesis of Tris(8-hydroxyquinoline) aluminum (Alq 3) nanowires under different conditions

Abstract

Tris(8-hydroxyquinoline) aluminum (Alq 3) is one of the most commonly used electron transporting and luminescent materials for organic light emitting diodes (OLEDs). It is thermally and morphologically stable to evaporate into thin films and it is a good green emitter. Due to its importance in OLEDs, the properties of Alq 3 have been extensively studied. Most of the studies, however, were concentrated on the single crystals, powder or thin films of Alq 3. Recently, synthesis of Alq 3 nanostructures, such as nanoparticles and nanowires, has been reported. Nanostructures have been attracting increasing attention because they may have new optical, electronic, magnetic, and mechanical properties compared with those of bulk materials. In this work, we reported synthesis of Alq 3 nanowires by heating Alq 3 powder in a gas flow. The nanowires were grown on glass substrates which were located in the downstream. The obtained nanostructures were characterized by scanning electron microscopy (SEM) and photoluminescence (PL). The effect of substrate temperatures, fabrication system geometry (i.e. source to substrate distance), the choice of gas, and gas flow rate on the resulting nanostructures were investigated. It is found that the synthesis conditions had significant effect on the morphologies of the resulting nanostructures, but the PL showed no significant dependence on the morphology.