ZnO and MgZnO nanocrystalline flexible films: Optical and material properties

Abstract

An emerging material for flexible UV applications is MgxZn 1-xO which is capable of tunable bandgap and luminescence in the UV range of ∼3.4eV-7.4eV depending on the composition x. Studies on the optical and material characteristics of ZnO and Mg0.3Zn0.7O nanocrystalline flexible films are presented. The analysis indicates that the ZnO and Mg0.3Zn0.7O have bandgaps of 3.34eV and 4.02eV, respectively. The photoluminescence (PL) of the ZnO film was found to exhibit a structural defect-related emission at 3.316eV inherent to the nanocrystalline morphology. The PL of the Mg0.3Zn0.7O film exhibits two broad peaks at 3.38eV and at 3.95eV that are discussed in terms of the solubility limit of the ZnO-MgO alloy system. Additionally, external deformation of the film did not have a significant impact on its properties as indicated by the Raman LO-mode behavior, making these films attractive for UV flexible applications. © 2011 Jesse Huso et al.