Comprehensive electronic structure of Si nanocrystal

الملخص EN

The properties of oxidized surface and core have been investigated.

using of STO-3G(Slater Type Orbitals)foundation is made to be able to compare RHF(Roothaan-Hartree-Fock)method with semiempirical methods using the complete neglect of differential overlap (CNDO)which uses Slater type orbitals (STO).

outcomes revealed that the electronic properties converge to some limit as the size of the nanocrystal increases.

Increasing the size of the core of a nanocrystal resulted in anraise of energy gap (3.54 eV), valance band width (14.21 eV), and cohesive energy (9.15 eV).The lattice constant of the core and oxidized surface parts illustrate a decreasing movement as the nanocrystal increases in size that converges to 0.528 nm.

Surface and core convergence to the same lattice constant reflects good adherence of oxide layer at the surface.

The nanocrystal surface shows smaller gap (1.08 eV) and higher valence band whilst compared to the core part due to the oxygen atoms at the surface the diminution of structural symmetry.