A study on the Raman spectra of Al-doped and Ga-doped ZnO ceramics

AlxZn1 O-x and GayZn1 O-y ceramics were synthesized through a solid-state reaction technique. The crystal phase of the samples was identified by an X-ray diffraction experiment. For each sample, the electrical resistivity was determined. The Al 2-mol%-doped and Ga 0.5-mol%-doped ZnO ceramics had the lowest resistivity. Raman measurement was performed to study the doping effects in the ZnO ceramics including ZnO single crystal as a reference. The line shape parameters, q(1) and Gamma(1), at the same certain doping rate and the solubility limit of AI (2 mol%) and Ga (0.5 mol%) in ZnO ceramics, are strongly related to the each other, and that the solubility limit plays an important role. The second-order Raman peak at 1162 cm (1) of the ZnO ceramics was fitted by Fano formalism. The Fano's fitting parameters, such as the lifetime of phonon and the degree of asymmetry degree of the second-order Raman peak changed as the amounts of dopants were varied. (C) 2008 Elsevier B.V. All rights reserved.