In this work porous silicon samples obtained by electrochemical etching were investigated. Using scanning probe microscope the morphology of porous silicon samples was studied. To determine the thickness of the porous layer and the pore diameter, micrographs were obtained using a scanning electron microscope. The dimensions of the nanocrystallites were determined from the Raman spectra. For the detection of vapors of organic compounds, planar structures were used. The results of the study confirmed the possibility of using nanoporous silicon as a sensitive material for the determination of acetonitrile and chloroform vapors. It is shown that the adsorption phenomena in porous silicon depend on its structure and morphology. It is established that the humidity of the air when detecting the vapors of organic compounds under investigation has a significant effect on the sensitivity. It is also shown that such structures can be used as instruments for measuring air humidity.

No abstract

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.

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.