ИСТИНА

Recent years scientific community attention has been transferred from porous silicon to arrays of Si nanowires (SiNWs) formed by metal-assisted chemical etching (MACE) due to high perfection of its crystal lattice and surface properties. The dependence of the linear and nonlinear optical properties of (SiNWs) on their structural properties was investigated. SiNWs had a strong scattering of light in the visible and infrared spectral range. Nonmonotonic dependence of the total reflectance of light from SiNWs on their length was discovered. It was found that in SiNWs the efficiency of frequency conversion of optical radiation, such as Raman scattering, coherent anti-Stokes Raman scattering and third-harmonic generation, were increased compared to c-Si substrates. Nonmonotonic dependence of the intensity of the interband photoluminescence in the range of 1100-1200 nm from SiNWs on their length was found. Usually in MACE hydrofluoric acid (HF) was used. But in this work we also tried to use green chemistry and HF was changed on NH4F. This procedure made MACE safer and environmentally friendly. All these results suggest similar optical properties of SiNWs obtained using green chemistry to the SiNWs obtained by the standard MACE method. It gives an opportunity to obtain high quality SiNWs for various applications in photonics and photovoltaics using green chemistry.