Electron tomography of (In,Ga)N insertions in GaN nanocolumns grown on semi-polar ( 11 2 ̄ 2 ) GaN templates

We present results of scanning transmission electron tomography on GaN/(In,Ga)N/GaN nanocolumns (NCs) that grew uniformly inclined towards the patterned, semi-polar GaN( 11 2...

Full description

Bibliographic Details
Main Authors: M. Niehle, A. Trampert, S. Albert, A. Bengoechea-Encabo, E. Calleja
Format: Article
Language:English
Published: AIP Publishing LLC 2015-03-01
Series:APL Materials
Online Access:http://dx.doi.org/10.1063/1.4914102
Description
Summary:We present results of scanning transmission electron tomography on GaN/(In,Ga)N/GaN nanocolumns (NCs) that grew uniformly inclined towards the patterned, semi-polar GaN( 11 2 ̄ 2 ) substrate surface by molecular beam epitaxy. For the practical realization of the tomographic experiment, the nanocolumn axis has been aligned parallel to the rotation axis of the electron microscope goniometer. The tomographic reconstruction allows for the determination of the three-dimensional indium distribution inside the nanocolumns. This distribution is strongly interrelated with the nanocolumn morphology and faceting. The (In,Ga)N layer thickness and the indium concentration differ between crystallographically equivalent and non-equivalent facets. The largest thickness and the highest indium concentration are found at the nanocolumn apex parallel to the basal planes.
ISSN:2166-532X