The energy band alignment of Si nanocrystals in SiO2

G. Seguini (1) , Sylvie Schamm-Chardon (2) , P. Pellegrino (3) , M. Perego (1)

1 IMM-CNR - Laboratorio MDM
2 CEMES-MEM - Matériaux et dispositifs pour l'Electronique et le Magnétisme
3 UB - Universitat de Barcelona

The determination of the energy band alignment between the 2.6-nm-diameter Si nanocrystals and the SiO2 host is achieved by means of photo-ionization/-neutralization and capacitance spectroscopy. The measured conduction and valence band offsets are 2.6 eV and 4.4 eV. The band gap is evaluated to be 1.7 eV by photoluminescence. These results indicate that the valence band offset at the Si nanocrystals/SiO2 interface is quite close to the one observed at bulk Si/SiO2 interface. On the contrary, we observe a clear upward shift (0.5 eV) of the conduction band in the Si nanocrystals/SiO2 system with respect to the bulk Si/SiO2 hetero-structure.

Domaines: Matière Condensée [cond-mat]

G. Seguini, Sylvie Schamm-Chardon, P. Pellegrino, M. Perego. The energy band alignment of Si nanocrystals in SiO2. Applied Physics Letters, 2011, 99 (8), pp.082107. ⟨10.1063/1.3629813⟩. ⟨hal-01745021⟩