Charging dynamics and strong localization of a two-dimensional electron cloud

Raphaelle Dianoux (1, 2) , Florence Marchi (3) , Henke Jan Smilde (4) , Nicolas Buffet (4) , Pierre Mur (4) , Fabio Comin (1) , Joël Chevrier (3)

1 ESRF - European Synchrotron Radiation Facility
2 SiNaps - Silicon Nanoelectronics Photonics and Structures
3 NEEL - NOF - Nano-Optique et Forces
4 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information

The dynamics of charge injection in silicon nanocrystals embedded in a silicon dioxide matrix is studied using electrostatic force microscopy. We show that the presence of silicon-nanocrystals with a density of 1011 cm2 is essential for strong localization of charges, and results in exceptional charge retention properties compared to nanocrystal-free SiO2 samples. In both systems, a logarithmic dependence of the diameter of the charged area on the injection time is observed on a time scale between 0.1 and 10 s (voltage ≤ 10 V). A field-emission injection, limited by Coulomb blockade, and a lateral charge spreading due to a repulsive radial electric field are used to model this logarithmic behavior. Once the tip is retracted, the electron cloud is strongly confined in the nanocrystals and remains completely static.

Mots clés: electrostatic force microscopy; charge effects in semiconducting nanostructures

Domaines: Micro et nanotechnologies/Microélectronique

Raphaelle Dianoux, Florence Marchi, Henke Jan Smilde, Nicolas Buffet, Pierre Mur, et al.. Charging dynamics and strong localization of a two-dimensional electron cloud. Nanotechnology, 2007, 18 (32), pp.325403. ⟨10.1088/0957-4484/18/32/325403⟩. ⟨hal-00088811⟩