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

Silicon nanoparticles (Si-NPs) obtained by electrochemical etching of silicon wafer were incorporated into various dielectric matrices using sol-gel method. To attain a wide range of dielectric constant and band gap energy, three matrices are selected (SiO2, ZrO2 and TiO2) 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 SiO2 matrix and ZrO2 matrix but not in TiO2 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.