Type

Journal Article

Authors

Peter J. Parbrook
Justin D. Holmes
Michael D. Morris
Colm O'Dwyer
Robert W. Martin
Colm Glynn
Timothy Collins
Michael Schmidt
Gunnar Kusch
Vitaly Z. Zubialevich
and 2 others

Subjects

Physics

Topics
self control transmission electron microscopy tem nanolithography gan nanorods atomic force microscopy thermal annealing electron microscopy hyperspectral imaging

Self-healing thermal annealing: surface morphological restructuring control of GaN nanorods (2016)

Abstract With advances in nanolithography and dry etching, top-down methods of nanostructuring have become a widely used tool for improving the efficiency of optoelectronics. These nano dimensions can offer various benefits to the device performance in terms of light extraction and efficiency, but often at the expense of emission color quality. Broadening of the target emission peak and unwanted yellow luminescence are characteristic defect-related effects due to the ion beam etching damage, particularly for III–N based materials. In this article we focus on GaN based nanorods, showing that through thermal annealing the surface roughness and deformities of the crystal structure can be “self-healed”. Correlative electron microscopy and atomic force microscopy show the change from spherical nanorods to faceted hexagonal structures, revealing the temperature-dependent surface morphology faceting evolution. The faceted nanorods were shown to be strain- and defect-free by cathodoluminescence hyperspectral imaging, micro-Raman, and transmission electron microscopy (TEM). In-situ TEM thermal annealing experiments allowed for real time observation of dislocation movements and surface restructuring observed in ex-situ annealing TEM sampling. This thermal annealing investigation gives new insight into the redistribution path of GaN material and dislocation movement post growth, allowing for improved understanding and in turn advances in optoelectronic device processing of compound semiconductors.
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Full list of authors on original publication

Peter J. Parbrook, Justin D. Holmes, Michael D. Morris, Colm O'Dwyer, Robert W. Martin, Colm Glynn, Timothy Collins, Michael Schmidt, Gunnar Kusch, Vitaly Z. Zubialevich and 2 others

Experts in our system

1
Peter J. Parbrook
University College Cork
Total Publications: 23
 
2
Justin D. Holmes
University College Cork
Total Publications: 182
 
3
Colm O'Dwyer
University College Cork
Total Publications: 121
 
4
Robert W. Martin
University College Cork
Total Publications: 4
 
5
Colm Glynn
University College Cork
Total Publications: 19
 
6
Timothy Collins
Trinity College Dublin
Total Publications: 6
 
7
Michael Schmidt
University College Cork
Total Publications: 29
 
8
Gunnar Kusch
University College Cork
Total Publications: 3
 
9
Vitaly Z. Zubialevich
University College Cork
Total Publications: 12