Synthesis and characterization of pure and Tb/Cu doped Alq3 nanostructures

Abstract

Tris (8-hydroxyquinoline) aluminum (Alq3) is an organic semiconductor molecule, widely used in optoelectronic devices. In this work we report on fabricating different nanostructures of Alq3 and characterize them using different techniques. Nanostructured films of Alq3 were grown using the physical vapor condensation and thermal-vapor transport methods. The as synthesized films were characterized by X-ray diffraction, scanning electron microscope, energy dispersive spectroscopy and absorption spectra. Nanoparticles and nanorods/nanowires are observed in the synthesized films. Tb and Cu doped Alq3 films were also produced and studied for their photoluminescence (PL) properties. When the original powder sample of Alq3 was excited by 378nm, one broad PL emission band is observed at around 515nm. The pure nanoparticles film shows similar band with a drastic increase in the intensity by a factor of 2. This has been attributed to the large specific surface area, which might has increased the absorption and then the quantum yields. The Tb and Cu doped films show also similar band with a slight shift in the peak position to the blue region, but with further enhancement in the peak intensity, particularly that of Cu. The PL intensity of Cu doped sample is around 1.5 times stronger than that of the pure Alq3 nanoparticles. This remarkable result on obtaining highly luminescent nanomaterial based on Cu doped Alq3 nanoparticles film might be useful for future organic light emitting diode display devices.