Luminescence and light guiding properties of Er and Li codoped ZnO nanostructures

Micro- and nanostructures of ZnO co-doped with Er and Li ions have been grown by a catalyst free vapor-solid method under constant N₂ flux. Nanowires and nanobelts with lengths of several microns, and thicknesses of a few hundreds of nanometers have been obtained. Scanning Electron Microscopy (SEM), X Ray Microanalysis (EDS) and micro-Raman spectroscopy have been used to characterize the samples. Luminescent emission has been studied by cathodoluminescence (CL). Modifications in the defect structure due to Li incorporation are observed. An increase in the relative intensity of the Er³⁺ - related 0.8 eV (1.54 µm) emission band in the co-doped samples has been observed. Micro-photoluminescence (µ-PL) has been used to investigate the optical properties of the structures. The establishment of optical resonant modes and wave guiding along both the longitudinal and transversal axes of the structures have been observed.