AB-INITIO STUDY OF THE ELECTRONIC-STRUCTURE OF F-19 IMPLANTED IN GAASAND GAN CRYSTALS

We have studied the nuclear quadrupole interaction of a fluorine atom implanted in gallium arsenide and gallium nitride cluster models using the ab-initio Hartree-Fock theory. For the three possible fluorine si tes in GaAs and GaN, we have determined the location of the implanted fluorine atom by using a self-consistent calculation, the electric fie ld gradient at the implanted atom, and the electronic structure. Good agreement is found with experimental data wherever they are avaliable. Predictions are made for the implanted fluorine site associated with the total energy and the electric field gradient which are expected to be measurable by a variety of experimental techniques.