Ni-rich phases identification in GaAs nanowire devices by mean of electron diffraction tomography

Rapid thermal annealing is a powerful tool for the preparation of ohmic contact at metal–semiconductor interfaces, and it can yield to complex inter-diffusion phenomena, as it has been extensively studied in the case of bulk GaAs[1]. We observed that the controlled thermal annealing of GaAs nanowire (NW) devices with Ni/Au electrodes promotes the diffusion of nickel into the nanowire, forming Ni-rich metallic alloy regions in the nanostructured body