SHALLOW DONORS IN GAN - A MAGNETIC DOUBLE-RESONANCE INVESTIGATION

The residual shallow donor in GaN is investigated by electron spin res onance and the Overhauser shift double resonance technique. From the r esolved quadrupolar splitting, we determine the electric field gradien ts at the Ga and the N site. The hyperfine interaction, as determined simultaneously from the Overhauser shift and the Knight shift, support s a delocalized donor wavefunction with an effective Bohr radius of 20 -30 Angstrom. Copyright (C) 1996 Elsevier Science Ltd