We report on charge injection experiments performed on single silicon nanoparticles and their analysis by Electric Force Microscopy (EFM). An analytical model is presented, enabling a quantitative determination of the charge state of the semiconductor nanoparticles from EFM signals, for arbitrary tip and nanoparticle shapes.
Experimentally, we provide an analysis of the capacitive and charge interactions taking place in EFM of silicon nanoparticles deposited on conductive substrates. We demonstrate that the weak image interactions associated with charged nanoparticles -of dipole-dipole type- can be identified from a spectroscopic EFM analysis.
Finally, we address the issue of the charge injection mechanisms. From the hysteretic behaviour of the charge injection spectroscopy, we separate volume versus surface charge effects. We show that charges are mostly injected in the nanoparticle volume, with however some residual injection on the nanoparticle surface. Mechanisms of the charge saturation are discussed.