Electronic Raman Scattering from Mg-Doped Wurtzite GaN

Electronic Raman scattering experiments have been carried out on both MBE and MOCVD-grown Mg-doped wurtzite GaN samples. Aside from the expected Raman lines, a broad structure (FWHM {approx_equal} 15 cm{sup {minus}1}) observed for the first time at around 841 cm{sup {minus}1} is attributed to the electronic Raman scattering from neutral Mg impurities in Mg-doped GaN. From the analysis of the temperature-dependence of this electronic Raman scattering signal binding energy of the Mg impurities in wurtzite GaN has been found to be E{sub b} {approx_equal} 172 {+-} 20 meV. These experimental results demonstrate that the energy between the ground and first excited states of Mg impurities in wurtzite GaN is about 3/5 of its binding energy.