| Summary: | InGaN/GaN single quantum well (SQW) and quantum dot (QD) samples were studied using optically detected X-ray absorption spectroscopy (OD-XAS). This is a powerful technique, capable of linking local structural environment information with the luminescence emission processes present. Ga K-edge OD-EXAFS analysis shows this technique to be site-selective for these samples and, from the emission related to the QW or QD structure, a percentage indium value was determined for each sample. Possible reasons why this siteselectivity is observed are considered, along with the implication of the results with respect to the nature of the mechanism responsible for exciton localisation within these structures. Further investigations were performed on the QD sample, including a depth profiling study based on spectra obtained at several different excitation energies and an analysis of the OD-XANES at the N K-edge. The application of pumpprobe micro-imaging OD-XAS to these types of samples is also examined.
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