Theoretical Modelling of Defects in Oxides
EMSL Project ID
2333
Abstract
We will model the structure and defect properties in KBr, SiO2, MgO, and possibly Al2O3 and ZrO2. The main topics will include: i) the structure and properties of oxygen vacancies and interstitial oxygen species, ii) the diffusion of oxygen species through oxide, iii) the role of structural disorder in defect properties, iv) the determination of absolute positions of bands and defect states with respect to the vacuum level and band offsets, v) the role of surface excitons and defect centers in halogen atom desorption from alkali halides. The mechanisms of diffusion of atomic and molecular oxygen species in crystalline and amorphous SiO2 will be discussed in conjunction with the silicon oxidation problem. We will investigate the role of structural disorder in determination of incorporation energies and spectroscopic properties of peroxy species and oxygen vacancies in amorphous silica. We will use periodic plane wave DFT and ab initio embedded cluster calculations to determine defect energies with respect to the bottom of the conduction band in silica and the vacuum level at the surface of MgO and KBr.
Project Details
Project type
Exploratory Research
Start Date
1999-10-01
End Date
2002-09-19
Status
Closed
Released Data Link
Team
Principal Investigator