Abstract
The issue of phase segregation, inherent to the MgZnO alloy system, was investigated via selective resonant Raman scattering. We demonstrate that it is a highly sensitive technique for the detection of embedded structural inhomogeneities. MgZnO thin-films with bandgaps that span the UV-range of 3.2–5.7 eV were realized. Under resonant conditions facilitated via different laser excitation energies, the LO-phonon behavior indicated that the phase segregation is in the range of 35%–65% Mg, in which domains of hexagonal-wurtzite and cubic-NaCl structures coexist. The scattering of the forbidden LO-mode of the cubic phase is discussed in terms of inversion-symmetry relaxation due to alloying.