Research Information System
Thesis Type: Postgraduate
Institution Of The Thesis: Gazi University, Turkey
Approval Date: 2018
Thesis Language: Turkish
Student: Rokaia Ibrahem
Supervisor: SEFER BORA LİŞESİVDİN
Abstract:In this study, the electronic and the optical properties of wz-ZnO and wz- MgxZn1-xO have been calculated for different Mg mole fractions using the Atomistic Toolkit-Virtual Nano Lab (ATK-VNL) software based on density functional theory (DFT). Our calculations are performed using the hybrid-generalized gradient approximation (GGA+U) formalism, where the Hubbard parameters are applied to Zn-3d electrons and O-2p electrons. The electronic properties calculations include the electronic band structures, the density of states and electron effective masses, whereas the optical properties calculations include the static dielectric functions, refractive indexes, extinction coefficients and absorption spectra of all the studied structures. The results show that the band gap energies increase as the Mg mole fractions increase, which corresponds with the previous experimental results. The electron effective masses calculation shows a linear dependence of the Mg mole fraction, but their values show overestimation. The absorption edges of studied structures move toward the higher energies region (the lower wavelengths region) as Mg mole fraction of MgxZn1-xO increases. The static dielectric constant of MgxZn1-xO decreases as Mg mole fraction increases. The dielectric constants of the high frequency of MgxZn1-xO are found to be very similar to the experimental results. In addition, the refractive indexes and the extinction coefficients move toward the higher energy region (the lower wavelength region).