Influence of intrinsic defects on the properties of zinc oxide.
The effects of oxygen vacancies and zinc interstitials on the structure and energy of zinc oxide were studied with the semiempirical MO method MSINDO. Cyclic clusters were chosen as model systems. Single and multiple removal of oxygen atoms and zinc interstitials in zinc oxide served to determine the defect formation energy and the band gap. The interaction between two and three oxygen vacancies was investigated. The vacancies cause a decrease of the band gap, which originates from an occupied defect level. This is also found for zinc interstitials under zinc rich conditions. The defect formation energy of such zinc interstitials is found to be lower than that of oxygen vacancies at 0 K but decreases for oxygen vacancies and increases for zinc interstitials with increasing temperature.
Jug
Karl
K
Theoretische Chemie, Universität Hannover, Callinstr. 3A, 30167 Hannover, Germany. jugthc@mbox.theochem.uni-hannover.de
Tikhomirov
Viatcheslav A
VA