Realization of vertically-aligned GaN n-p core-shell nanoscale structures using top-down fabrication

Vertically aligned core-shell p-n nanostructures are technologically significant due to their potential applications in a variety of devices such as light-emitting diodes, laser diodes, photodetectors, and solar cells. Such structures developed in III-Nitride material system are expected to increase device efficiency, partially due to mitigating detrimental effects of spontaneous electrical polarization. Despite significant progress in the synthesis of nitride core-sell nanostructures using both bottom-up and top-down paradigms, fabrication of large arrays of these nanostructures with controlled morphology, orientation, dopant incorporation, and site-specific nucleation is still a challenge. One of the most challenging aspects of making high quality GaN nanopillar arrays using top-down approach is to design an etching protocol for producing high-aspect ratio structures while inducing minimal damage to the sidewalls and preventing the etch-mask erosion.[1]