0000000000315427
AUTHOR
V. Hortelano
Non-radiative recombination centres in catalyst-free ZnO nanorods grown by atmospheric-metal organic chemical vapour deposition
We have investigated the cathodoluminescence (CL) emission and the Raman spectra along individual ZnO nanorods grown by a catalyst-free method. The spatial correlation between the CL emission and the defect related Raman modes permits establishing a correspondence between the non-radiative recombination centres (NRRCs) and the defects responsible for the 275 cm−1 Raman band. According to this relation, the NRRCs in these nanorods are tentatively associated with complexes of zinc interstitials.
High resolution X-ray diffraction, X-ray multiple diffraction and cathodoluminescence as combined tools for the characterization of substrates for epitaxy: the ZnO case
The goal of this work is to show the capability of X-ray multiple diffraction (XRMD) to be used in combination with high resolution X-ray diffraction (HRXRD) and cathodoluminescence (CL) as an easy and simple methodology to determine structural and surface defect-related characteristics of samples that could be used as substrates for epitaxial growth. For this study ZnO {0001}-oriented samples have been used in view of their use as substrates for homoepitaxy. The miscut and bending of the samples have been analyzed by measuring the position of the X-ray diffraction peaks. The presence of multiple crystallographic domains and their characteristics have been studied by HRXRD (from the allowed…
Non radiative recombination centers in ZnO nanorods
ABSTRACTNowadays, the nature of the non radiative recombination centres in ZnO is a matter of controversy; they have been related to extended defects, zinc vacancy complexes, and surface defects, among other possible candidates. We present herein the optical characterization of catalyst free ZnO nanorods grown by atmospheric MOCVD by microRaman and cathodoluminescence spectroscopies. The correlation between the defect related Raman modes and the cathodoluminescence emission along the nanorods permits to establish a relation between the non radiative recombination centers and the defects responsible for the local Raman modes, which have been related to Zn interstitial complexes.
Spray pyrolytic deposition of ZnO thin layers composed of low dimensional nanostructures
Abstract ZnO nanolayers composed of fine nanostructures have been successively grown by spray pyrolytic deposition at 300 ∘ C over amorphous glass substrates. As deposited samples were analysed by scanning electron microscopy (SEM), showing a granular morphology with grain size in the limit of the microscope resolution. CL measurement shows a broad near band edge (3.4 eV) emission of ZnO in the UV region and the defect level emissions in the green region of the spectrum. The use of intermittent spray pyrolytic deposition is shown as an alternative to increase the homogeneity of the samples when temperatures near to the precursor pyrolytic decomposition is selected, long depositions times a…