Identification and Properties of Defects in GaP

We report an application of self-consistent pseudopotential Green's-function calculations to the problem of identification of defects in GaP. The results are in agreement with and support the EPR-based identification of the P antisite defect, but contradict the assumptions that led to the identification of the Ga vacancy. We reexamine other possibilities using the results of our calculations and find that C at Ga sites is the only center whose properties are consistent with the available data.