Open Access Nano Express

Epitaxial Catalyst-Free Growth of InN Nanorods onc-Plane Sapphire

I Shalish12*, G Seryogin1, W Yi1, JM Bao13, MA Zimmler1, E Likovich1, DC Bell1, F Capasso1 and V Narayanamurti1

Author Affiliations

1 Harvard University, Cambridge, MA, 02138, USA

2 Ben Gurion University, Beer Sheva, Israel

3 University of Houston, Houston, TX, 77004, USA

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Nanoscale Research Letters 2009, 4:532-537  doi:10.1007/s11671-009-9276-z

Published: 27 February 2009

Abstract

We report observation of catalyst-free hydride vapor phase epitaxy growth of InN nanorods. Characterization of the nanorods with transmission electron microscopy, and X-ray diffraction show that the nanorods are stoichiometric 2H–InN single crystals growing in the [0001] orientation. The InN rods are uniform, showing very little variation in both diameter and length. Surprisingly, the rods show clear epitaxial relations with thec-plane sapphire substrate, despite about 29% of lattice mismatch. Comparing catalyst-free with Ni-catalyzed growth, the only difference observed is in the density of nucleation sites, suggesting that Ni does not work like the typical vapor–liquid–solid catalyst, but rather functions as a nucleation promoter by catalyzing the decomposition of ammonia. No conclusive photoluminescence was observed from single nanorods, while integrating over a large area showed weak wide emissions centered at 0.78 and at 1.9 eV.

Keywords:
InN; Nanorods; Nanowires; Epitaxial growth; Sapphire; Catalyst-free; Ni