Analysis of Porous Nanosilicon by Raman Spectroscopy

Technologies for the production of nanostructured silicon and porous nanosilicon are presented. A method for the synthesis of porous nanosilicon by electrochemical etching is described. The main parameters for the generation of porous silicon with given characteristics are presented. The results from investigations of samples of porous silicon obtained with a InVia Raman Renishaw spectrometer, with which it is possible to record and identify both amorphous and crystalline phase components in samples, are described. The crystal structure of the samples was determined from the results of granulometric investigations. The absence of amorphous silicon in the samples was confirmed by approximation of the Raman spectra. A shift of the lines toward smaller energies, characteristic of nanoparticles with nanoparticles with decreased size, is observed in the Raman spectra. A stable strong band in the region of 700–900 nm, which confirms the nanocrystalline nature of the samples, is observed in the photoluminescence spectra. The effectiveness and sensitivity of Raman spectroscopy, which make it possible to determine even insignificant changes in the crystalline and amorphous fraction of the silicon structures, were demonstrated.