0000000000294702
AUTHOR
Vladimir Lysenko
showing 3 related works from this author
Photo-induced cubic-to-hexagonal polytype transition in silicon nanowires
2019
Transformation of the crystalline lattice in silicon nanowires from cubic diamond (cub-Si) to hexagonal diamond (hex-Si) was observed under laser irradiation at intensities above 10 kW cm−2 (wavelength of 473 nm) by appearance of an additional peak in their Raman spectra in the range from 490 to 505 cm−1. Formation of the hex-Si phase in SiNWs is favoured by strong mechanical stresses caused by inhomogeneous photo-induced heating, which results in a singlet–doublet splitting of the Raman peaks for LO and TO phonons at about 517 and 510 cm−1, respectively. The estimated values of the photo-induced mechanical stresses and temperatures required for the polytype transformation in SiNWs correspo…
Mesoporous SiC with Potential Catalytic Application by Electrochemical Dissolution of Polycrystalline 3C-SiC
2018
Electrochemical dissolution of highly doped (ρ ∼ 1 mΩ·cm, n-type) polycrystalline 3C-SiC in HF/H2O and HF/H2O/ethanol solutions allowed production of porous silicon carbide (por-SiC) and soluble carbon fluorooxide nanoparticles as a byproduct. The por-SiC is a crystalline material with large pore volume, surface area close to 100 m2 g–1, and open mesoporous structure. The surface of por-SiC is covered with a thin carbon-enriched layer, bearing carboxylic acid groups. Depending on the SiC resistivity, etchant composition, and current density, three different types of por-SiC morphology, namely, a macroporous tubular, mesoporous hierarchical, and mesoporous filamentary were revealed. A qualit…
Size and Surface Chemistry Tuning of Silicon Carbide Nanoparticles.
2017
International audience; Chemical transformations on the surface of commercially available 3C-SiC nanoparticles were studied by means of FTIR, XPS, and temperature-programmed desorption mass spectrometry methods. Thermal oxidation of SiC NPs resulted in the formation of a hydroxylated SiO2 surface layer with C3Si–H and CHx groups over the SiO2/SiC interface. Controllable oxidation followed by oxide dissolution in HF or KOH solution allowed the SiC NPs size tuning from 17 to 9 nm. Oxide-free SiC surfaces, terminated by hydroxyls and C3Si–H groups, can be efficiently functionalized by alkenes under thermal or photochemical initiation. Treatment of SiC NPs by HF/HNO3 mixture produces a carbon-e…