Real time evolution of charge decay characteristics in silicon nanocrystals

In this paper, we present a study on the charge trapping and charge decay mechanism in silicon nanocrystals (nc-Si) embedded in silicon-dioxide (SiO₂) by electrostatic force microscopy (EFM). From the characteristic decay time τ, lateral diffusion of the stored charges in nc-Si is observed. Increases in the size of charge cloud as a function of time is an evidence of lateral charge diffusion. In addition, charge interaction between the charges with opposite charge sign is also evident from the oscillation in the time dependence of the size of charge cloud. Neighboring charge with opposite charge sign enhanced the lateral charge diffusion.