Dataset for "Optical Investigation of Semi-polar (11-22) AlGaN with High Al Composition"

This dataset provides the experimental data used to generate the figures in the paper entitled "Optical Investigation of Semi-polar (11-22) AlGaN with High Al Composition".

The data discussed and presented in the paper was recorded using a variable pressure field emission scanning electron microscope (FEI Quanta 250) which is equipped with a custom-built cathodoluminescence (CL) hyperspectral imaging system. The CL system collects the emitted light at an angle of 45° with respect to the incident electron beam using a Cassegrain reflecting objective. The light is then dispersed using a 125 mm focal length spectrograph (Oriel MS125) and detected using an electron-multiplying charge-coupled device (Andor Newton). As the electron beam scans across the sample surface, a whole CL spectrum is recorded per pixel building up a 3D hyperspectral data set. 2D CL images can then be extracted from the hyperspectral data set, such as peak energy, intensity or half width.

Abstract of the paper:

Exciton localization disturbs uniform population inversion, leading to an increase in threshold current for lasing. High Al content AlGaN is required for the fabrication of deep ultra-violet LDs, generating exciton localization. Photoluminescence and cathodoluminescence measurements have been performed on high quality semi-polar (11-22) AlxGa1-xN alloys with high Al composition in order to study the optical properties of both the near-band-edge (NBE) emission and the basal-plane stacking faults (BSFs) related emission, demonstrating different behaviours. Further comparison with the exciton localization of their c-plane counterparts exhibits that the exciton localization in semi-polar (11-22) AlGaN is much smaller than that in c-plane AlGaN.