English: Indium-gallium nitride is a semiconductor alloy that emits light when irradiated by energetic particles. A small crystal cluster has accidentally grown during the w:MOVPE process. The lightness corresponds to its standard w:SEM image, whereas the colour overlayers were added according to the light emitted under the electron beam. Blue and green channels are roughly natural colours, while red encodes the ultraviolet emission. The image demonstrates that InGaN/GaN structures are highly anisotropic, and so are their cathodoluminescence properties.
Image taken in the Institute of Physics, Czech Academy of Sciences, using Philips XL30 ESEM equipped with custom color-resolved cathodoluminescence photomultiplier setup. Author acknowledges the great help of R. Horešovksý.