<title>Optical properties of silicon nanopowders formed using power electron beam evaporation</title>

Abstract

Silicon nanopowders were produced using power electron-beam-induced evaporation of bulk silicon ingots in various gas atmospheres. Optical properties of the nanopowders were studied with the use of photoluminescence and Raman spectroscopy techniques. Photoluminescence peaks in the visible region of the spectrum have been detected at room temperature in silicon nanopowders, produced in argon gas atmosphere. Strong short-wavelength shift of the photoluminescence peaks can be result of quantum confinement effect for electrons and holes in small silicon nanocrystals (down to 2 nm in diameter). The size of silicon nanocrystals was estimated from Raman spectroscopy data. The calculated in frame of effective mass model optical gaps for silicon nanocrystals of spherical shape are in good correlation with experimental photoluminescence data. With the use of silicon ingot evaporation by power electron-beam at air atmosphere the Si0₂ nanopowders were produced. The attempts of deposition of silicon nanocrystal films from the nanopowders on silicon substrates were carried out.