Novel Na(+) doped Alq3 hybrid materials for organic light-emitting diode (OLED) devices and flat panel displays.

Pure and Na(+) -doped Alq3 complexes were synthesized by a simple precipitation method at room temperature, maintaining a stoichiometric ratio. These complexes were characterized by X-ray diffraction, Fourier transform infrared (FTIR), UV/Vis absorption and photoluminescence (PL) spectra. The X-ray diffractogram exhibits well-resolved peaks, revealing the crystalline nature of the synthesized complexes, FTIR confirms the molecular structure and the completion of quinoline ring formation in the metal complex. UV/Vis absorption and PL spectra of sodium-doped Alq3 complexes exhibit high emission intensity in comparison with Alq3 phosphor, proving that when doped in Alq3 , Na(+) enhances PL emission intensity. The excitation spectra of the synthesized complexes lie in the range 242-457 nm when weak shoulders are also considered. Because the sharp excitation peak falls in the blue region of visible radiation, the complexes can be employed for blue chip excitation. The emission wavelength of all the synthesized complexes lies in the bluish green/green region ranging between 485 and 531 nm. The intensity of the emission wavelength was found to be elevated when Na(+) is doped into Alq3 . Because both the excitation and emission wavelengths fall in the visible region of electromagnetic radiation, these phosphors can also be employed to improve the power conversion efficiency of photovoltaic cells by using the solar spectral conversion principle. Thus, the synthesized phosphors can be used as bluish green/green light-emitting phosphors for organic light-emitting diodes, flat panel displays, solid-state lighting technology - a step towards the desire to reduce energy consumption and generate pollution free light.

Synthesis and characterization of pure and Li⁺ activated Alq3 complexes for green and blue organic light emitting diodes and display devices.

Pure and Li(+)-doped Alq3 complexes were synthesized by simple precipitation method at room temperature, maintaining the stoichiometric ratio. These complexes were characterized by X-ray diffraction, ultraviolet-visible absorption and Fourier transform infrared and photoluminescence (PL) spectra. X-ray diffraction analysis reveals the crystalline nature of the synthesized complexes, while Fourier transform infrared spectroscopy confirm the molecular structure, the completion of quinoline ring formation and presence of quinoline structure in the metal complex. Ultraviolet-visible and PL spectra revealed that Li(+) activated Alq3 complexes exhibit the highest intensity in comparison to pure Alq3 phosphor. Thus, Li(+) enhances PL emission intensity when doped into Alq3 phosphor. The excitation spectra lie in the range of 383-456 nm. All the synthesized complexes other than Liq give green emission, while Liq gives blue emission with enhanced intensity. Thus, he synthesized phosphors are the best suitable candidates for green- and blue-emitting organic light emitting diode, PL liquid-crystal display and solid-state lighting applications.

Study of photophysical properties of different metal complexes of Alq3.

Different metal complexes of Alq3 (K(+) , Sr(2+) , Ca(2+) and Mg(2+) ) were synthesized by the precipitation method. The characterization of photoluminescence showed that presence of Mg(2+) ion enhances photoluminescence of Alq3 phosphor. The emission spectra are observed at 560 nm when excited at a wavelength of 440 nm. The phosphor is excited at a longer wavelength in the blue region of small energy, so that it could be used as lamp phosphor. It is observed that the prepared phosphor AlMgq5 is more suitable than Alq3. The ionic radii of K(+) , Sr(2+) , Ca(2+) and Mg(2+) ions are in decreasing order. Therefore, the remarkable properties of AlMgq5 could be considered as promising materials as opto- or optoelectronic materials.