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Abstract: Dependence of the stored charges and the tunneling voltages on the tunneling SiO2 thickness for Si nanoparticles embedded in a SiO2 layer formed by the sonochemical method was investigated by using electrostatic force microscopy (EFM) measurements. Bright-field transmission electron microscopy images showed that Si nanoparticles were embedded in a SiO2 layer. EFM images for the Si nanoparticles embedded in a SiO2 layer under applied bias voltages showed that the localized charges remained in the Si nanoparticles embedded in a SiO2 layer. The stored charge in the Si nanoparticles embedded in a SiO2 layer increased with a decrease in the tunneling SiO2 thickness. While the threshold tunneling voltage increased with an increase in the tunneling oxide thickness, the mean amplitude of the tunneling voltage increased with a decrease in the thickness of the tunneling SiO2 layer. [Copyright &y& Elsevier]

Abstract: Capacitance–voltage (C–V) and electrostatic force microscopy (EFM) measurements on Si nanocrystals (Si-NCs) formed by using the sonochemical method were carried out to investigate the charging effects of the Si-NCs. Transmission electron microscopy images and atomic force microscopy images showed that the Si-NCs were created inside the SiO2 layer. The C–V curve and the EFM image showed that the Si-NCs embedded in the SiO2 layer experienced charging effects. The macroscopic surface charge density determined from the C–V curve was in reasonable agreement with the microscopic local value obtained from the EFM image. The present results indicate that the EFM technique might provide a promising method for investigating charging effects in various kinds of nanocrystals embedded in the insulating layer. [Copyright &y& Elsevier]