ANALYSIS OF ELECTRON DISTRIBUTION AND CHEMICAL BONDING AT THE INTERFACE REGION OF SI(001)/ AL2O3(001), SI(001)/ TIO2(001), AND SI(001)/ SIO2(001) HETEROSTRUCTURES

All calculations were performed using the Vienna Ab initio Simulation Package (VASP 6. 5) [11, 14], employing the Projector Augmented Wave (PAW) method [13, 14, 15] parameterized by Perdew, Burke, and Ernzerhof (PBE) [9] within the generalized gradient approximation (GGA). Spin polarization was considered to accurately obtain the system energy. A cutoff energy of 620 eV was used. For geometry optimization, force and energy convergence criteria of 0. 02 eV/Å and 10−5 eV, respectively, were employed. For sampling the Brillouin zone, Gammacentered k-point meshes of 2 × 3 × 1, 2 × 4 × 1, and 2 × 3 × 1 were used for Si(001)/ Al2O3(001), Si(001)/ TiO2(001), and Si(001)/ SiO2(001), respectively [9, 10, 11, 12, 13, 14, 15].