Electronic transport in Si-SiO₂ nanocomposite films

We report experimental investigations and modeling of the electronic transport in Si-SiO₂ nanocomposite films. The current-voltage characteristics measured at room temperature are interpreted as due to high field-assisted tunneling. The activation energies from the current-temperature curves are given by the energy separations between quantum confinement electronic states, determined from a quantum well model. Consequently, the calculated mean diameter of a nanodot (5.2 nm) is in good agreement with the microstructure data (5 nm). Also, the potential barrier between nanocrystalline Si and amorphous SiO₂, previously obtained for nanocrystalline oxidized porous Si (2.2 eV), is confirmed.