Cathodoluminescence study of plastically deformed bulk ZnO single crystal

Vickers microindentation of bulk (0001¯) ZnO single crystal has been studied by means of a scanning microscope using cathodoluminescence (CL) monochromatic imaging and spectral modes. A main feature of the sample's deformation is the propagation of the latter away from the indenter contact diameter, in well-defined directions, characterizing the hexagonal crystal systems. An attempt is made to understand plastic deformation mechanism, which is responsible for the observed deformation behavior. The deformation-produced dislocations act as nonradiative recombination centers, which is confirmed by the absence of any additional emission band and the diminution of the band edge luminescence intensity in the Cl spectra after micro-indentation.