Photoluminescent boron-doped (100)-oriented porous silicon fabricated on a p-type silicon substrate by electrochemical etching in a solution containing fluorosilicic acid and ethanol is studied. The morphological, structural, and optical properties of silicon nanostructures obtained in solutions containing H₂(SiF₆) and ethanol are analyzed in comparison with the corresponding characteristics of samples formed in solutions of HF and ethanol. The morphological, structural, and optical properties were studied using scanning probe microscopy and spectrophotometry. It is shown that the porous silicon samples formed in solutions containing H₂(SiF₆) and ethanol have better optical properties, in particular, they exhibit more intense photoluminescence than the samples obtained in HF–ethanol solutions.

In the work, porous silicon with observed photoluminescence was made from a p-type silicon substrate doped with boron and crystallographic orientation (100) using the method of electrochemical etching in a solution containing H₂(SiF₆) (silicon hydrofluoric acid) and ethyl alcohol. Thin carbon films were sprayed by high-frequency magnetron sputtering at room temperature onto the surface of porous silicon. The resulting carbon-doped thin films of porous silicon were irradiated on a pulsed electron booster and comparisons were made with nonirradiated films of porous silicon. To understand the effect of carbon on the properties of porous silicon films samples were analyzed by Raman spectroscopy, spectrophotometry, and scanning probe microscopy (SPM). The results of the SPM showed that the roughness of the samples increases after carbon doping on the surface of porous silicon. Thus, for the first time, experimental results were obtained on the effect of irradiation on carbon-doped porous silicon obtained in a solution containing hydrogen hexafluorosilicate H₂(SiF₆) and a significant change in its optical properties was shown. The results of the study showed that irradiated samples of carbon-doped porous silicon have better photoluminescence compared to nonirradiated samples.

This study explores the enhancement of porous silicon (PS) surfaces through surface modification with titanium dioxide (TiO₂), silver (Ag), titanium (Ti), and tungsten (W) nanoparticles using the magnetron sputtering technique. PS samples were initially fabricated via electrochemical etching of crystalline silicon, employing two different electrolytes: hydrofluoric acid (HF) and hexafluorosilicic acid (H₂SiF₆). The structural and optical properties of these samples were meticulously analyzed using Raman spectroscopy, reflectance spectroscopy, and scanning electron microscopy (SEM). The results revealed that surface modification with metal nanoparticles and metal oxides led to significant modifications in near-surface structural order, evidenced by shifts in Raman spectra towards higher frequencies. These shifts are attributed to local near-surface crystalline modifications rather than bulk crystallinity changes. Photoluminescence (PL) measurements demonstrated noticeable changes in intensity and peak shifts, suggesting alterations in the energy levels and structural composition of the PS. Reflectance spectra exhibited interference patterns and variations in material transparency, which were dependent on the type of nanoparticles and thickness of the deposited nanoparticle layer. Moreover, the choice of electrolyte was found to play a crucial role in determining the porosity and optical characteristics of the PS, with the alternative H₂SiF₆ electrolyte producing distinct structural and optical effects compared to the traditional HF electrolyte. These findings highlight the significant impact of nanoparticle surface modification and electrolyte selection on tailoring the properties of PS, offering new pathways for optimizing its use in photonics, electronics, and catalytic applications.

Boron doped porous silicon with the observed photoluminescence with a crystallographic orientation of (100), which was fabricated based on a p-type silicon substrate using electrochemical etching in a solution containing hexafluorosilicic acid and ethyl alcohol was studied. A comparative analysis of the morphology, structural and optical properties of silicon nanostructures obtained in a solution containing H2(SiF6) and ethanol and samples obtained in a solution containing HF and ethanol was performed. Morphology, structural and optical properties were studied using scanning probe microscopy and spectrophotometry. It was shown that samples of porous silicon obtained in a solution containing H2(SiF6) and ethanol are characterized by improved optical properties, in particular, they exhibit more intense photoluminescence compared to samples obtained in solutions with HF and ethyl alcohol.