Surface Structure for Silicon Nanoparticles

Abstract

A model depend on ratio number atoms of the Surface to the internal atoms used to calculate the mean bonding length (dmean(r)) of silicon nanoparticles with radius (r) in the range of (1.2nm ≤ r ≤ 10nm). The results compared with the (dmean(r)) which measured from high resolution transmission electron microscope (HRTEM) in the range of (r), using AUTO CAD software for measuring nanoparticle radius and the spacing between adjacent fringes that correspond to dhkl – spacing. The results obtained that the theoretical model is in good agreement with the experiment for all (r) range. The lattice parameter (dmean(r)) are found to increases from (0.235nm) for bulk Si up to (0.262nm) for nanoparticles having a size down to 3nm, then it is increased sharply at about the critical radius of silicon nanoparticle (r = 1nm), which related to the atomic surface behavior.