Investigation of nanostructure properties in InGaN/GaN multiple quantum wells by X-ray diffraction analysis

We report a study on the nanostructure properties of InGaN/GaN multiple quantum well (MQW) heterostructures. The temperature dependent photoluminescence (PL) spectra from the InGaN/GaN MQWs with different indium contents were carried out. Based on the band-tail states model, the degree of the localized states dispersion is estimated. The broadening of localized states in the samples is enhanced as the indium content is increasing. To further investigate the results, X-ray diffraction spectra of the samples were measured and analyzed. The nanostructure size distribution of the MQW heterostructure is determined via the calculation of the diffracted intensity of X-ray beam in Fourier space. It is found that the sample with higher indium content exhibits a wider nanostructure size distribution, and is consistent with the experimental results from PL spectra.

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