| Nanomaterials are typically defined as amorphous or polycrystalline solids with particle diameters or grain sizes of 100 nm or less. Recently, a number of innovative efforts have opened the opportunity to a new class of materials, which allow to control both the flow of light and the dynamics of photons. The nanostructured periodic materials, Photonic Crystals, and waveguides embedded in them have been very attractive subjects of current research. Another attractive approach is to utilize rare earth emission within nanocrystals. The restricted geometry of rare earth ions in nanocrystals may affect luminescence behavior with respect to energy transfer and electron-phonon interactions in a bulk crystal, providing efficient light emission for future integration with optoelectronic devices.; Based on such concepts addressed above, this dissertation has focused on two facets of nanomaterials investigation that are applicable to active 1.5 μm emission planar devices. First, the synthetic opaline films, 6 μM in thickness, were fabricated from self-assembly of a monodisperse colloidal suspensions of silica spheres with a diameter of 310 nm. This film showed an optical gap centered around 730 nm with a full width at half maximum (FWHM) of 50 nm, exhibiting 20% of maximum reflectivity. This study showed that the photon bands are the result of interplay between the coherent scattering due to the periodic structure and the non-coherent (diffuse) scattering due to the individual spheres, the latter exhibiting Mie resonance, the scattering coefficient is inversely proportional to λ2 in regions of optical wavelength. Further, it was indicated that Me resonance remaining in the photon bands should be nearly eliminated to minimize optical loss and maximize band gap strength. This may be possible by organizing uniform features of dielectric structures, whether opal or inverse-opal, with smaller building blocks, the size of which are below theoretical scattering limit.; Second, Erbium Titanate (ETO) nanopowders with a well defined crystallinity were fabricated by using complexed precursors of erbium and titanium. The relatively strong infrared fluorescence was obtained for pyrochlore ETO (Er 2Ti2O7) nanopowders (≈40 nm), whose emission spectrum centered around 1530 nm with a FWHM of 70 nm. The anticipated optical property changes in terms of phonon energy were in good agreement with Er fluorescence and photoluminescence decay measurements in this materials. This study indicated that pyrochlore nanocrystal will serve a good host leading to efficient erbium emission at 1.53 μm. |
