I have been a PhD-student in the PhD4Energy project. I am engaged in project area 2 ”Growth (nitrides)”. From the start, I have been directly involved in the research team dealing with growth and characterization of nitride semiconductor nanowires. As a first sub-topic, I took a very active role in development of growth of GaN pyramid structures and the effort of enhancing the quality of these structures. The work has involved preparation of templates for growth, as made by e-beam lithography or nano-imprint lithography and etching procedures enabling ideal nucleation of GaN in ultra-small openings in silicon-nitride thin film.