Home > Research > Publications & Outputs > The origin of shape, orientation, and structure...

Links

Text available via DOI:

View graph of relations

The origin of shape, orientation, and structure of spontaneously formed wurtzite GaN nanorods on cubic Si(001) surface

Research output: Contribution to journalJournal articlepeer-review

Published
Close
<mark>Journal publication date</mark>06/2013
<mark>Journal</mark>Crystal Growth and Design
Issue number6
Volume13
Number of pages6
Pages (from-to)2407-2412
Publication StatusPublished
<mark>Original language</mark>English

Abstract

We elucidate the atomistic level details of the formation of 1-D GaN nanostructures on Si(001) by molecular beam epitaxy. In a multitechnique study, we understand the epitaxy and role of the unintentional interfacial SiNx layer in determining the shape, structure, and organization of the nanofeatures. The 1-D GaN features are seen to be m-faceted and grow along the Si(111) planes and thus are tilted with a 4-fold symmetry on the cubic Si(100) surface. The interfacial mismatch induced dislocations are shown to provide the nucleation centers for the spiral 1-D growth, while their local density determines their evolution into solid rods, tubes, or c-tubes. The unintentional interfacial nitridation of the substrate forms discontinuous amorphous mounds that provide the epitaxial contact to the substrate and also laterally isolate the rods/tubes, enabling them to grow laterally in their equilibrium hexagonal wurtzite structures. We consolidate the results into a schematic model to unveil the underlying mechanism and demonstrate the subtle relationship between the kinetics of growth and the interfacial properties.