ANALYSIS OF POLARIZATION ANISOTROPY ALONG THE C-AXIS IN THE PHOTOLUMINESCENCE OF WURTZITE GAN

The polarization of photoluminescence (PL) was investigated on (<1(1)o ver bar 00>) GaN grown by metalorganic vapor phase epitaxy. We found t hat the PL intensity and wavelength have polarization dependence paral lel and perpendicular to the c axis, We quantitatively analyzed the de pendence and found that, since the crystal field of wurtzite GaN along the c axis is strong enough to fix the \z] axis of p functions at the c axis, the difference in symmetry between three valence bands appear s as the polarization anisotropy in radiative emission, even in bulk G aN. (C) 1997 American Institute of Physics.