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


Autoria(s): Conroy, Michele; Li, Haoning; Zubialevich, Vitaly Z.; Kusch, Gunnar; Schmidt, Michael; Collins, Timothy; Glynn, Colm; Martin, Robert W.; O’Dwyer, Colm; Morris, Michael D.; Holmes, Justin D.; Parbrook, Peter J.
Data(s)

16/12/2016

16/12/2016

31/10/2016

15/12/2016

Resumo

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.

Formato

application/pdf

Identificador

Conroy, M., Li, H., Zubialevich, V. Z., Kusch, G., Schmidt, M., Collins, T., Glynn, C., Martin, R. W., O’Dwyer, C., Morris, M. D., Holmes, J. D. and Parbrook, P. J. (2016) 'Self-Healing Thermal Annealing: Surface Morphological Restructuring Control of GaN Nanorods', Crystal Growth & Design, 16(12), pp. 6769-6775.

16

12

6769

6775

1528-7483

http://hdl.handle.net/10468/3389

10.1021/acs.cgd.6b00756

Crystal Growth & Design

Idioma(s)

en

Publicador

American Chemical Society

Direitos

© 2016 American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in Crystal Growth and Design, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/acs.cgd.6b00756

Palavras-Chave #GaN nanorods #Thermal annealing #Transmission electron microscopy (TEM) #Hyperspectral imaging, #Nanolithography #Electron microscopy #Atomic force microscopy
Tipo

Article (peer-reviewed)