Theoretical investigation of nitrogen-vacancy defects in silicon

Nitrogen-vacancy defects are important for the material properties of silicon and for the performance of silicon-based devices. Here, we employ spin polarized density functional theory to calculate the minimum energy structures of the vacancy-nitrogen substitutional, vacancy-dinitrogen substitutionals, and divacancy-dinitrogen substitutionals. The present simulation technique enabled us to gain insight into the defect structures and charge distribution around the doped N atom and the nearest neighboring Si atoms. Using the dipole-dipole interaction method, we predict the local vibration mode frequencies of the defects and discuss the results with the available experimental data.