Influence of point defects' concentration on the ZnO matrix – a simulation study
Numerical simulations of the effect of the presence of point defects in the matrix of ZnO were carried out using MATLAB computation procedure. The variation of impurity atom concentration with the energy gap was simulated. The plot obtained exhibited an exponential increase in energy gap with respect to the concentration of impurity atoms and corresponded to the theoretical solution of impurity modeling in ZnO. The computation procedures showed that oxygen vacancies and shallow donor nature of hydrogen impurities screen acceptor in ZnO. Oxygen interstitials were found to have high formation energies and were as such, unlikely to occur. The potentials and challenges of the application of ZnO for semiconductor devices were considered. Findings showed that recent studies of native point defects did not adequately explain the often observed n – type conductivity but that was rather accountable to the introduction of impurities at the processing stages.
Keywords: ZnO, Impurities, Oxygen Vacancies, Semiconductor Devices, Simulation