Optical Properties Of Nano Ordered Structures

As the information society advances, optical and electronic devices in fields of display, data storage, energy and so on are required to possess more and better fuctions. However, traditional materials are difficult to meet this requirement. With the surface effect and small size effect, nanostructure materials especially for nano ordered materials that exhibit excellent optical, magnetic, and thermal properties has received widely attention and become the focus in the related research area.Most of nano ordered materials consist of nanoparticles, nanowires and nanorods, etc. On the basis of nano spherical ordered structures, the optical properties of nano core-shell ordered structure and nanotube quasi—ordered structure were systematically investigated. The study was described as three parts:Firstly, finite difference time domain (FDTD) method was employed to obtain the UV—vis transmission/reflection spectra of nano spherical close—packed structures, i.e., photonic crystals. The calculated results were in excellent agreement with that from the performed experiment and corresponding literatures in this article. Secondly, the nano ordered core-shell structure with the spherical core was researched. The effect of the core offset and its direction with respect to the sphere center in core—shell structure on optical properties of the nano core-shell ordered structure was simulated by FDTD method. The simulated results indicated that the full width at half maximum (FWHM) of transmission peak and the relative FWHM varied linearly with the offset parallel to the [111] direction, and hardly changed with the offset perpendicular to the [111] direction. The nano ordered core—shell structure with the ellipsoid core was also discussed. It was discovered that the relative FWHM of its transmission peak could tuned by its shape and azimuth of this ellipsoid core. In summary, it was be instructive and meaningful to tune the optical properties of the nano odered core—shell structure. Thirdly, the nanotube quasi—ordered structure was studied. TiO2nanotube was prepared by the hydrothermal method, and the quasi—ordered structures were respectively prepared by the vertical deposition method and the two—substrate vertical deposition method. The UV—Vis reflection spectra were used to characterized these structures. Compared to the spectra of samples from the vertical deposition method, the counterpart from the two—substrate vertical deposition method had a more apparent peak, which suggested that the two-substrate vertical deposition method can prepare a more ordered structure.Thus, more quasi—ordered structures were prepared by this method, under different concentrations of TiO2. Meanwhile, the nanotube quasi—ordered stucture was simulated by the FDTD method. It was found that the theoretical results showed the same rule as the experiment, and the simulated results fitted well with the experiment, which comfirmed its order.