ABSTRACT
We study the energetics of N-related defects in Zn-based II-VI semiconductors such as ZnS, ZnSe, and ZnTe through first-principles pseudopotential calculations and find that a substitutional N at an anion site to be most stable at low doping levels. From the calculated formation energies, we determine defect concentrations and find that p-type doping levels are different between ZnSe and ZnTe. The maximum hole density in ZnTe is estimated to be higher by about 5 times than ZnSe, which is in good agreement with the experiments. We also investigate the microscopic mechanism for the compensation of N acceptors in ZnSe.
