Electron screening in nanostructures

Distributions of electrical potential and carrier concentration, the contact capacity, and its voltage dependence are calculated for Schottky contacts to various types of nanostructures, including nanolayers and nanowires of different thickness, as well as their arrays. The results demonstrate a dramatic dependence on the nanostructure geometry. Single nanostructures and planar arrays of nanowires cannot provide effective screening of the contact potential, so that the total stored charge and the structure capacity depend on the separation between external contacts. On the contrary, for nanolayer and two-dimensional nanowire arrays, the mutual electrostatic interaction between different elements provides effective screening with the screening length equal to the interelement distance, which determines the contact capacity and its voltage dependence. (c) 2007 American Institute of Physics.