Infrared spectroscopy of Mg-H local vibrational mode in GaN with polarizedlight

Magnesium-doped GaN grown by organometallic vapor phase epitaxy has been in vestigated by multitransmission infrared spectroscopy with the wave vector not along the c axis. This allows searching for local vibrational modes of complexes aligned along the c axis that cannot be seen by "normal" optical configuration. This technique, combined with polarized light, allows the pr ecise determination of the geometry of the complexes. It has been found tha t the stable "magnesium-hydrogen" complex is not aligned along the c axis. The structure of this complex, including the angle between the electric dip ole induced by the local mode and the c axis, has been determined. No other hydrogen-related complex aligned along the c axis has been detected.