ANALYSIS OF POROUS NANOSILICON BY RAMAN SPECTROSCOPY

Abstract

The technologies of obtaining nanostructured silicon, including porous nanosilicon are presented. The method for the synthesis of porous nanosilicon using electrochemical etching is described. The main parameters of the generation of porous silicon with specified characteristics are given. The results of the study of nanostructured porous silicon samples using a Renishaw InVia Raman Spectrometer are described in detail. This spectrometer permits to register and identify both amorphous and crystalline phase components in the samples. According to the results of granulometric studies, the crystal structure of the samples is established. The approximation of the Raman spectra confirms the absence of amorphous silicon in the samples under study. In the Raman spectra of the samples, a shift of lines towards lower energies is observed, which is characteristic of nanoparticles with a decrease in their size. The photoluminescence spectra of the synthesized samples of porous silicon exhibit a stable intense band in the range 700—900 nm, which confirms the nanocrystalline nature of the samples. We demonstrate the efficiency and sensitivity of Raman spectroscopy, which makes it possible to register even insignificant changes in the crystalline and amorphous fractions of silicon structures.