Study of silicon nanoparticles in dielectric oxides obtained by sol–gel route

Abstract

Silicon nanoparticles (Si-NPs) obtained by electrochemical etching of silicon wafer were incorporated into various dielectric matrices using solÀgel method. To attain a wide range of dielectric constant and band gap energy, three matrices are selected (SiO 2 , ZrO 2 and TiO 2 ) and the Si-NPs were incorporated in these matrices at different concentrations. Structural studies by transmission electron microscopy and Raman spectroscopy confirm the presence of Si-NPs in the matrices. Moreover, the significant compressive stress induced by the matrix is observed. Photoluminescence (PL) studies show that Si-NPs preserve their luminescent properties in SiO 2 matrix and ZrO 2 matrix but not in TiO 2 matrix. The PL peak position depends not only on the dimension of Si-NPs but also depends on their concentrations. This is due to the coupling effect between the nanoparticles which increases with concentration.

Silicon Electrochemistry in Molten Salts

“…The method is attractive in producing SiO 2 precursors on metals, first of all, due to technical convenience: there is no need for expensive specific equipment, rather dip-coating or spin-coating is used. Sol–gel formation of SiO 2 layers on the Si substrate has recently been applied to produce antireflection coatings. − This method was also used to incorporate Si-NPs into various dielectrics (SiO 2 , ZrO 2 , and TiO 2 ) or in a sol–gel matrix, which showed good photoluminescence stability . A great challenge is production of a compact silicon layer by a sol–gel route, most probably, in organic solvents to avoid silicon oxidation.…”

“…Sol−gel formation of SiO 2 layers on the Si substrate has recently been applied to produce antireflection coatings. 138−140 This method was also used to incorporate Si-NPs into various dielectrics (SiO 2 , ZrO 2 , and TiO 2 ) 141 or in a sol−gel matrix, which showed good photoluminescence stability. 142 A great challenge is production of a compact silicon layer by a sol−gel route, most probably, in organic solvents to avoid silicon oxidation.…”