[en] The optical properties of ordered arrays of silicon nanopillars (Si NPs) were investigated. Electron Beam Lithography (EBL) followed by Inductively Coupled Plasma Reactive Ion Etching (ICP-RIE) was used for Si NPs fabrication. Si NPs were chemically and electrically passivated through the deposition of TiONx nanolayer. The silicon nanopillars were characterized by using scanned electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM). We demonstrate that a various colors can be obtained by exploiting the resonant light scattering properties of individual Si NP. In addition the low temperature photoluminescence from Si NPs was investigated. The peak photoluminescence energy was observed at 0.83 μm and 1.14 μm. Raman scattering enhancement was found too

[en] The optical-reflection spectra of microarrays of silicon nanopillars are studied in the visible and near-IR regions. The microarrays of silicon nanopillars are formed by electron-beam lithography and reactive ion etching. The reflection spectra of nanopillar arrays with pitches of 400, 600, 800, and 1000 nm are measured. The height of nanopillars in the array is 0.5 μm, and the diameter varies from 150 to 240 nm. It is noted that the spectral features of the reflection are caused by increased absorption of individual nanopillars and interference effects inside the array. A relation between the geometric parameters of nanopillars and the resonance reflection characteristics is determined taking into account the influence of the substrate.

[en] Abstract—The results of investigating the spectral characteristics of reflection from silicon nanopillar (Si NP) microarrays in the wavelength region from 400 to 1100 nm are presented. The Si nanopillars are formed by electron lithography on a negative resist with subsequent reactive ion etching. The Si nanopillars are etched through a resist mask and SiO₂ 100 nm thick. In the spectra of reflection from nanopillar microarrays, minima are observed, the position of which depends strongly on the Si nanopillar diameter.

[en] Scanning electron microscopy, spectroscopic ellipsometry, and current-voltage and current-temperature measurements were employed to characterize nanowhisker structures grown by molecular-beam epitaxy on Si(111) substrates. Small clusters of gold deposited on the Si surface were used as the seeds for nanowhisker growth. The diameter of grown nanowhiskers and their length ranged from 70 to 200 nm and from 580 to 890 nm, respectively. The whiskers were found to inherit the (111) orientation of the Si substrate. By means of spectroscopic ellipsometry in the range 1.5-4.77 eV, lateral optical inhomogeneity of the nanowhisker layer was revealed, with optical properties of the layer substantially differing from those of single-crystal Si. Electrical measurements point to the presence of a Schottky barrier with height 0.70 eV in the structure and to the presence of electrically active centers non-uniformly distributed over the nanowhisker length

[en] The electrical and optical properties of silicon nanopillars (Si NPs) are studied. Electron-beam lithography and reactive ion etching are used for the formation of ordered Si-NP arrays. The Si NPs with a diameter from 60 to 340 nm and a height from 218 to 685 nm are formed. The Si NPs are coated with a TiON"x layer with a thickness of 8 nm for chemical and electrical passivation of the surface. Scanning electron microscopy and atomic-force microscopy are used to characterize the obtained structures. The Si-NP arrays acquire various colors when exposed to “bright-field” illumination. The spectra of reflection from the Si-NP arrays in the wavelength range 500–1150 nm are obtained

[en] Highlights: • A deposition of supersonic methane plasma flow on silicon substrate produces amorphous oxygenated hydrocarbon (CO_xH_y) film. • The thickness, composition, and wettability of the film depend on the substrate temperature. • A rise of the substrate temperature from 500 to 700 °C promotes the sp"3-hybridization carbon formation. - Abstract: Since amorphous oxygenated hydrocarbon (CO_xH_y) films are promising engineering materials a study of the structure and composition of the films depending on the conditions of synthesis is important for controlling of their physicochemical properties. Here, we used the methods of scanning and transmission electron microscopy, X-ray photoelectron, near-edge X-ray absorption fine structure, Fourier transform infrared and Raman spectroscopy to reveal changes in the chemical connectivity of CO_xH_y films grown on silicon substrates heated to 300, 500, and 700 °C using a supersonic flow of methane plasma. It was found that the CO_xH_y films, deposited at 300 and 500 °C, were mainly composed of the sp"2-hybridized carbon areas with various oxygen species. A rise of the substrate temperature caused an increase of the portion of tetrahedral carbon atoms as well as carboxyl and hydroxyl groups. With growth of the substrate temperature, the film thickness reduced monotonically from 400 to 180 nm, while the film adhesion improved substantially. The films, deposited at lower temperatures, showed high hydrophilicity due to porosity and presence of oxygenated groups both at the surface and in the bulk.