Super-cell calculation of the nitrogen defect in diamond and cubic siliconcarbide

The nitrogen point defect in diamond and cubic SiC was studied using an ab- initio plane wave pseudopotential approach that highlights the differences in the conduction bands of the two materials. Each N defect energy level is located relative to the various energy bands. The N defect level in diamon d shows very little dispersion through the bands, which is indicative of it s localized character. On the contrary, in cubic SiC the defect is far less localized, with the level essentially depending on the occupancy of either the C or Si site. Both sites may give n-type behavior, but N on the C site is preferred, with a defect level substantially pinned to the conduction b and. (C) 2000 Published by Elsevier Science S.A.