Selective growth of ordered hexagonal InN nanorods

Well-ordered and vertically aligned InN nanorods with high aspect ratios are synthesized by hydride vapor phase epitaxy (HVPE) using the selective area growth (SAG) approach. The growth occurs through the apertures of a SiNx masked Ga-polar GaN/c-Al2O3 template for adjusted growth temperature and V/III ratio. The nanorods exhibit a hexagonal shape without any rotation around the growth axis. The wurtzite structure and the high crystalline quality of InN nanorods are confirmed by X-ray diffraction (XRD) as well as by high-resolution transmission electron microscopy (HR-TEM). Only few stacking faults are identified at the bottom part of the nanorods. Photoluminescence (PL) displays an emission peak centered at 0.77 eV which agrees with the band gap of InN. These promising achievements, which go far beyond the existing InN growth limitations, pave the way towards the integration of pure InN in future devices.