Superstructure of self-aligned hexagonal GaN nanorods formed on nitrided Si(111) surface

Kumar, P. and Tuteja, M. and Kesaria, Manoj and Waghmare, U.V. and Shivaprasad, S. M. (2012) Superstructure of self-aligned hexagonal GaN nanorods formed on nitrided Si(111) surface. Applied Physics Letters, 101 (13). pp. 131605-131608. ISSN 0003-6951

Abstract

We present here the spontaneous formation of catalyst-free, self-aligned crystalline (wurtzite) nanorods on Si(111) surfaces modified by surface nitridation. Nanorods grown by molecular beam epitaxy on bare Si(111) and non-stoichiometric silicon nitride interface are found to be single crystalline but disoriented. Those grown on single crystalline Si3N4 intermediate layer are highly dense c-oriented hexagonal shaped nanorods. The morphology and the self-assembly of the nanorods shows an ordered epitaxial hexagonal superstructure, suggesting that they are nucleated at screw dislocations at the interface and grow spirally in the c-direction. The aligned nanorod assembly shows high-quality structural and optical emission properties.