Spatially-resolved cathodoluminescence in GaN nanorods and in AIGaN/GaN multiquantum discs having different quantum confinement states

The optical properties of self-assembled GaN nanorods and GaN/AIGaN multiquantum discs are investigated by using cathodoluminescence (CL) measurements at room temperature. The nanostructure has a different dimension along the growth direction, leading to different confinement energy states. The dependence of the optical properties on the different confinement energy states along the growth direction is clearly demonstrated using the dependence of the CL image on the photon energy (ECL).