Non-radiative recombination centres in InGaN/GaN nanowires revealed by statistical analysis of cathodoluminescence intensity maps and electron microscopy.

The methodology of statistical analysis of cathodoluminescence intensity mappings on ensembles of several hundreds of InGaN/GaN nanowires used to quantify non-radiative recombination centres was validated on InGaN/GaN nanowires exhibiting spatially homogeneous cathodoluminescence at the scale of single nanowires. Cathodoluminescence intensity variations obeying Poisson's statistics were assigned to the presence of randomly incorporated point defects acting as non-radiative recombination centres. Additionally, another type of non-radiative recombination centres, namely extended defects leading to spatially inhomogeneous cathodoluminescence intensity at the scale of single InGaN/GaN nanowires are revealed by high resolution scanning transmission electron microscopy, geometrical phase analysis and two-beam diffraction conditions techniques. Such defects are responsible for deviations from Poissons's statistics, allowing one to achieve a rapid evaluation of the crystallographic and optical properties of several hundreds of nanowires in a single cathodoluminescence intensity mapping experiment.&#xD.