||Light emitting devices based on organic and anorganic compounds
||Ghitu Institute of Electronic Engineering and Nanotechnologies, ASM
||Phd. Sirbu Lilian
||Laboratory of Nanotechnologies
||Nanocompounds, ZnO, polymers, diodes
Areas of activities in nanotechnology include physical, chemical and biological research, synthesis and exploration of the properties and development of nanomaterials and nanodevices for use in different fields of science and nano-engineering.
The congruence of polymers with inorganic materials offer new possibilities to develop new nanomaterials with different properties and nanocomposites that are better than their components. Previous experimental study demonstrated that most classes of nanocomposite materials give new properties more favourable than macrocomponents properties. Therefore, nanocomposite materials have a big challenge for implementation in many areas of sciences and industry, such as nonlinear optics, sensors, photonics, new optical and electrical media for recording information, nanofibres and other systems. Of particular importance is the choice of inorganic and organic components of composite materials for specific applications.
Zinc oxide is a material characterized by a wide direct band gap (3.37 eV at 300K), with a low specific resistivity which allows to use it for the manufacture of light emitting diodes. ZnO is characterized by high concentrations of native defects: vacancies, interstitial atoms of oxygen and zinc, supra-stoichiometry of oxygen (vacancies of zinc, VZn), leading to the possibility for modification of the optical properties, conductivity and luminescence intensity in the "green" region and also in the "red" part of the spectrum. Thus, the development of the technology for obtaining nanocomposites p / n-ZnO-polymer with an attractive architecture, with a variable concentration of native defects which is an actual task for the development of optoelectronic devices possessing predicted optical and conductive properties.
Combining semiconductor nanostructures and polymers leads to a new way of preparation of nanocomposites (ZnO, poly(azometin-fluorene), poly(fluorene-oxadiazole-azometin), poly(azometin-oxadiazole), poly(amide-oxadiazole-fluorene ), etc.), to broaden the scope of use and exploration of physicochemical properties.