Abstract
We report on the ultraviolet photoluminescence (UV-PL) and Raman properties of wurtzite MgxZn1−xO nanopowders of average size ∼30nm that were synthesized via the thermal decomposition method. For the studied composition range of 0⩽x⩽0.26, the room-temperature UV-PL was found to be tuned by ∼0.24eV towards the UV spectral range, and the PL emission was established to be due to an excitonic-type recombination mechanism. The first-order longitudinal optical (LO) Raman mode was found to exhibit a blueshift of ∼33cm−1 and the second-order LO a shift of ∼60cm−1. The LO mode of the nanopowders is discussed in terms of a mixed A1-E1 symmetry phonon known as a quasi-LO mode. The observed 30cm−1 blueshift indicates that the E1 is the principal symmetry component in the Raman scattering of the MgxZn1−xO nanopowders.