Digital micro-photogrammetry in analysis and modeling habit and sectoral structure of real high-pressure high-temperature single-crystal diamonds.

We demonstrate the potential of using digital stereo micro-photogrammetry for the analysis and modeling of the habit and sectoral structure of real high-pressure high-temperature single-crystal diamonds. A prototype scanning system with a resolution of 5 μm has been implemented based on a digital single-lens reflex camera, making it possible to create highly accurate reproductions of crystal shapes with a minimum size of 4 mm. This method makes it possible to monitor the effect of actual conditions on the physical processes of crystal growth, which is a useful advance for the development of active device elements based on semiconductor diamonds.

Low-Temperature Reduction of Graphene Oxide: Electrical Conductance and Scanning Kelvin Probe Force Microscopy.

Graphene oxide (GO) films were formed by drop-casting method and were studied by FTIR spectroscopy, micro-Raman spectroscopy (mRS), X-ray photoelectron spectroscopy (XPS), four-points probe method, atomic force microscopy (AFM), and scanning Kelvin probe force (SKPFM) microscopy after low-temperature annealing at ambient conditions. It was shown that in temperature range from 50 to 250 °C the electrical resistivity of the GO films decreases by seven orders of magnitude and is governed by two processes with activation energies of 6.22 and 1.

Infrared Reflectance Analysis of Epitaxial n-Type Doped GaN Layers Grown on Sapphire.

Infrared (IR) reflectance spectroscopy is applied to study Si-doped multilayer n/n/n-GaN structure grown on GaN buffer with GaN-template/sapphire substrate. Analysis of the investigated structure by photo-etching, SEM, and SIMS methods showed the existence of the additional layer with the drastic difference in Si and O doping levels and located between the epitaxial GaN buffer and template. Simulation of the experimental reflectivity spectra was performed in a wide frequency range.

Silicon Substrate Strained and Structured via Cavitation Effect for Photovoltaic and Biomedical Application.

A hybrid structure, which integrates the nanostructured silicon with a bio-active silicate, is fabricated using the method of MHz sonication in the cryogenic environment. Optical, atomic force, and scanning electron microscopy techniques as well as energy dispersive X-ray spectroscopy were used for the investigation of the morphology and chemical compound of the structured surface. Micro-Raman as well as X-ray diffraction, ellipsometry, and photovoltage spectroscopy was used for the obtained structures characterization.

Possibility of graphene growth by close space sublimation.

Carbon films on the Si/SiO2 substrate are fabricated using modified method of close space sublimation at atmospheric pressure. The film properties have been characterized by micro-Raman and X-ray photoelectron spectroscopy and monochromatic ellipsometry methods. Ellipsometrical measurements demonstrated an increase of the silicon oxide film thickness in the course of manufacturing process.