0000000000883834
AUTHOR
N. Mironova-ulmane
Investigation of Silicon Carbide Polytypes by Raman Spectroscopy
Abstract Polytypes of colourless and coloured single crystals of silicon carbide (SiC) grown on SiC substrates by chemical vapour deposition are studied using Raman spectroscopy supplemented by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. The SEM analysis of the defect stacking faults, inclusions of defects and their distribution has shown that they correlate with the peak positions of the obtained Raman spectra and with the XRD data on the crystal structure
<title>Origin of visible photoluminescence in NiO and Ni<formula><inf><roman>c</roman></inf></formula>Mg<formula><inf><roman>1-c</roman></inf></formula>O single crystals</title>
A study of the visible photoluminescence in single-crystal NiO and NicMg1-cO (c = 0.99, 0.98 and 0.95) solid solutions is presented for the first time. Two wide luminescence bands, peaked at approximately 12000 cm-1 and approximately 18500 cm-1, were observed. The dependence of their intensity and position on the excitation energy, temperature, and composition were investigated. We attribute the origin of two photoluminescence bands to the impurity- or defect perturbed Ni2+ excitons.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.