The effects of bi-layer catalysts and its annealing on the growth of GaN nanowires

We report an evaporation reaction to synthesize GaN nanowires at 800°C on metallic bi-layer catalyst-coated substrates and on the bi-layer catalyst-annealed substrates through the reaction of GaN and NH₃. The annealing temperatures of catalyst layers before the GaN growth were 700°C and 850°C. Bi-layer metallic catalysts were constituted with Au, Ni, Al, and In. The growth differences caused by the stacking sequence of bi-layer catalysts and the annealing conditions were investigated. The understanding of those differences can help to know the growth mechanism.