Abstract
The electronic and atomic structure of isovalent substitutional P and As impurities in GaN is studied theoretically using a self-consistent plane-wave pseudopotential method. In contrast with the conventional isovalent III-V systems, and are shown to exhibit deep gap levels. The calculated donor energies are and eV, respectively, and the double donor energies are and eV, respectively. The -like gap wave function is found to be strongly localized on the impurity site. Outward atomic relaxations of and are calculated for the nearest-neighbor Ga atoms surrounding neutral and respectively. The relaxation increases by for the positively charged impurities. The impurity-bound exciton binding energy is calculated at and eV for and The former is in good agreement with the experimental data eV) whereas the latter is offered as a prediction. No clear Jahn-Teller symmetry lowering distortion, suggested by the one-electron configuration, is found for and
- Received 30 January 1998
DOI:https://doi.org/10.1103/PhysRevB.58.1367
©1998 American Physical Society