Measuring two dimensional strain state of AlN quantum dots in GaN nanowires by nanobeam electron diffraction

Nanobeam electron diffraction (NBED or NBD) is a transmission electron microscope (TEM) based technique able to measure strain with nanometre spatial resolution. This technique is especially well designed for nanostructures as reference diffraction pattern can be acquired anywhere on the sample. NBED is here applied on AlN/GaN superlattices grown on SiC and results compared to finite element simulations in order to assess the accuracy of the method. Strain profiles were then acquired with success on GaN nanowires presenting 3 nm GaN inclusions separated by 3 nm thick AlN.