In Dy 3+ and Li + codoped ZnO nanowires, the additives accumulate preferentially in {0001} planes, resulting in serious breakdown of the translational symmetry in ab plane and modification of the phonon oscillation field. Not only acoustic overtones, silent optical modes, surface optical (SO) phonon modes, and multi-phonon processes can be effectively observed in the nonresonant Raman scattering (RS) and the Fourier-transform infrared (FTIR) spectra, but the quasi-LO and TO modes of mixed A 1 and E 1 symmetry also show a noticeable red shift from E 1 symmetry (in ab plane) to A 1 symmetry (along c axis). The presence of dislocations and internal strain at the surface layer rich in additives, coming from the segregation of additives, forms a quasi-bilayer system, resulting in the appearance and enhancement of SO phonon modes in RS and FTIR spectra. The Fano interference, originating from the interaction between the discrete scattering from phonons and the continuum scattering from laser-induced electrons in the doped nanostructures, leads to typical asymmetric lineshapes on the lower wavenumber sides.

In ZnO hierarchical heterostructures of zinc antimonate nanoislands on ZnO nanobelts, the substitution of Sb(5+) for Zn(2+) induces lattice contraction and a variation in vacancy defects, and moreover the preferential accumulation and segregation of Sb in [001] planes results in the intense perturbation of atomic motion in the a-b plane. Under nonresonant conditions, nonpolar E(2)(high) and polar quasi-longitudinal optic (LO) modes decrease in frequency due to finite-size and phonon confinement effects. Under resonant conditions, localized excitons can ionize to free carriers and form plasmons at higher excitation power density, resulting in the transformation of scattering coupling from localized exciton-LO-phonon to LO-phonon-plasmon. The intensity ratio of 2LO/1LO decreases and multiphonon scattering shows a decrease in frequency with unequal neighboring interval, and moreover the scattering coupling between the continuum of electron-hole plasmon and the discrete LO phonons causes an asymmetric lineshape.