The nature of P and N defects was studied by means of pseudopotential total-energy calculations. Various charge states of the P and N impurities which occupied Zn sites (antisite defects) or interstitial sites (interstitial defects) were considered, and their structural properties were investigated. Their formation energies were calculated as a function of Se electronic and electronic chemical potentials. The calculated electronic properties and formation energies were used to investigate the role which was played by impurities in the p-type doping of ZnSe. The results suggested that the difficulty of p-type doping by P resulted from compensation of the shallow acceptors by antisite defects, PZn, which acted as triple donors. In the case of N, the concentrations of antisite and interstitial defects were too low to cause such compensation; which was consistent with the successful p-type doping of ZnSe with N.

K.W.Kwak, D.Vanderbilt, R.D.King-Smith: Physical Review B, 1995, 52[16], 11912-9