The growth of InN on GaN/sapphire by metalorganic vapor-phase epitaxy (MOVPE) using tertiary-butylhydrazine (tBHy) was studied by varying temperature, V/III-ratio, growth time and carrier gas between nitrogen and hydrogen. The growth was characterized in-situ by spectroscopic ellipsometry and ex-situ by high resolution X-ray diffraction, atomic force microscopy and scanning electron microscopy. In contrast to ammonia, it was predicted that tBHy should allow InN growth for a much wider growth window and low Will-ratios with growth temperatures below 600 degrees C. However, over a wide range of growth parameters only growth of metallic indium droplets was observed. (C) 2010 Elsevier B.V. All rights reserved.