The purpose of this study was researching the optical properties of Al-doped zinc oxide (ZnO) nanorods and nanotubes arrays by nanoimprint lithography. First, the substrate processed with nanoimprint lithography to form nanohole arrays. Based on the processed substrate we grown the Al-dope ZnO nanorods which incorporated Al(NO3)3·9H2O as the Al source via the hydrothermal method. The zinc oxide nanorods were grown by hydrothermal method because it’s a simple and effective way for low temperature synthesis. The structure of Al-doped ZnO nanorods were affected by PH value of growing solution. Due to the Al source was aluminum nitrate, so we added the ammonia water to control the PH value of growing solution. Until grown the vertically oriented Al-dope ZnO nanorods that row orderly. The ZnO nanorods was transformed to nanotube via a chemical aqueous etching process with well-controlled reaction time. Therefore, the Aldoped ZnO nanorods and nanotubes arrays were obtained. Finally, the Al-doped ZnO nanorods and nanotubes arrays were characterized by field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), Energy Dispersive Spectrometer (EDS) and X-ray diffraction (XRD). The FESEM and TEM images showed the morphologies of Al dope ZnO nanorods were row orderly on the substrate which processed with nanoimprint lithography. The XRD and EDS analysis showed that the Al element could be successfully doped into the ZnO lattice.
We exhibit a structure built with inorganic and organic material nanostructure arrays. The zinc oxide (ZnO) nanorods were synthesized by hydrothermal method and could be the precursor model to build our nanostructure. The as-fabricated ZnO nanorods were then surrounded with the inorganic material, lead telluride (PbTe). It could be filled with the organic material, Poly Methyl Methacrylate (PMMA), in the hexagonal hole after the ZnO nanorods were removed by simple chemical aqueous etching process. Finally, we can obtain an organic/PbTe array matrix nanostructure.The thermoelectric properties of as-fabricated device were measured and temperature dependence of physical mechanism for organic and inorganic hybrid nanostructure was discussed.
We report on the fabrication and measurement of ultrathin a-Si solar cells with plasmonic back contacts composed of nanopattern dendritic/shrub-like Ag nanostructures that exhibit enhanced short circuit densities compared cells with flat back contacts. The morphology of the Ag nanostructure can be well controlled by the reaction time. When the proposed structure was used in the solar cell. The back-reflector of solar cell can be well designed by various Ag nanostructures and periods. A one-dimension shrub-like Ag nanostructure with spacing of 600 nm, exhibited a 14 % increase in short-circuit current density and a 20% increase in energy conversion efficiency are observed. This study indicates that the dendritic/shrub-like Ag nanostructure can be applied as a enhancing conversion configuration for ultrathin a-Si solar cells.
Various silver nanostructures, semi-ball, jungle, and dendritic, are demonstrated by an
electrical deposition process. The formation of silver nanostructures with various morphologies is
studied by the mechanism of the diffusion limited aggregation (DLA) model. A array pattern of silver
nanostructures can be obtained when the conductive substrate was used in a uniform electrical filed. A
thickness 500 nm of Alq3 thin-film was covered on the silver nanostructure by thermal evaporation
method. The strongest intensity of Alq3 green emission was observed when the pattern-array dendritic
silver nanostructure was covered by Alq3. It can be explained with the plasmonic coupling due to the
Alq3 and dendritic nanostructure. The result can help us to further application the patterned-array
silver dendritic nanostructure for advanced opto-electronic device.
We have designed and fabricated a hollow optical waveguide with omnidirectional reflectors (ODRs) on a silicon substrate. The pattern is defined by photolithography on a (100) silicon wafer. The groove is etched by inductive coupled plasma. Plasma-enhanced chemical vapor deposition technology is used to deposit six-pair Si/SiO2 (0.111/0.258 µm) multilayer stacks on the sample. Finally, the top of the sample is covered with an identical ODR. Hence, the light is confined in a hollow waveguide.
In this study, we design and fabricate a hollow optical waveguide with omni-directional reflectors in silicon-based materials. A groove is etched by inductive coupled plasma (ICP) with photolithographic process on (100) silicon wafer. The width of the groove is varied from 3.5 to 5.5 micrometer for different waveguide designs. The depth of the groove is 1.2 micrometers. Plasma enhanced chemical vapor deposition is used to deposit six pairs of Si/SiO2(0.111/0.258micrometers) on the samples. Finally, the top of the sample is covered by another silicon substrate on which the identical omni-directional reflector has been also deposited. By wafer bonding technology, the top omni-directional reflector can be combined with the groove to form a hollow optical waveguide. Light with the wavelength at 1.55 micrometers can be confined by the omni-directional reflectors at single mode operation. Polarization independent hollow optical waveguides can be achieved with this fabrication process.