ИСТИНА

The advantage of using silicon nanowires in sensorics, photovoltaics, photonics, micro- and optoelectronics is associated with unique properties, such as visible photoluminescence (PL), extremely low total reflection, enhancement of Raman scattering, interband PL, etc. In this work, large areas of of porous silicon nanowires (pSiNWs) arrays were obtained by the method of metal assisted chemical etching (MACE) of heavy doped silicon wafers. The influence of concentration of H2O2 on the structural and optical properties of pSiNWs were studied in detail. Growth rate, reflectance in middle IR spectral region, visible PL and PL quantum yield were measured. According to scanning electron microscopy images, theresulting arrays of porous nanowires were shown to have two types of porosity, and the growth rate of different porous layers depends on the concentration of H2O2. Visible PL in spectral range 500-1100 nm was observed and explained by the radiative recombination of excitons in small Si nanocrystals on the surface and in the volume of pSiNWs. The calculated quantum yield of pSiNWs reached 3%. This work was supported by the Russian Science Foundation (Grant № 17-12-01386).