Facet recovery and light emission from GaN/InGaN/GaN core-shell structures grown by metal organic vapour phase epitaxy on etched GaN nanorod arrays

The use of etched nanorods from a planar template as a growth scaffold for a highly regular GaN/InGaN/GaN core-shell structure is demonstrated. The recovery of m-plane non-polar facets from etched high-aspect-ratio GaN nanorods is studied with and without the introduction of a hydrogen silsesquioxane passivation layer at the bottom of the etched nanorod arrays. This layer successfully prevented c-plane growth between the nanorods, resulting in vertical nanorod sidewalls (∼89.8°) and a more regular height distribution than re-growth on unpassivated nanorods. The height variation on passivated nanorods is solely determined by the uniformity of nanorod diameter, which degrades with increased growth duration. Facet-dependent indium incorporation of GaN/InGaN/GaN core-shell layers regrown onto the etched nanorods is observed by high-resolution cathodoluminescence imaging. Sharp features corresponding to diffracted wave-guide modes in angle-resolved photoluminescence measurements are evidence of the uniformity of the full core-shell structure grown on ordered etched nanorods

Quantum well engineering in InGaN/GaN core-shell nanorod structures

We report the ability to control relative InN incorporation in InGaN/GaN quantum wells (QWs) grown on the semi-polar and non-polar facets of a core-shell nanorod LED structure by varying the growth conditions. A study of the cathodoluminescence emitted from series of structures with different growth temperatures and pressures for the InGaN QW layer revealed that increasing the growth pressure had the effect of increasing InN incorporation on the semi-polar facets, while increasing the growth temperature improves the uniformity of light emission from the QWs on the non-polar facets.</p

Quantum well engineering in InGaN/GaN core-shell nanorod structures

We report the ability to control relative InN incorporation in InGaN/GaN quantum wells (QWs) grown on the semi-polar and non-polar facets of a core-shell nanorod LED structure by varying the growth conditions. A study of the cathodoluminescence emitted from series of structures with different growth temperatures and pressures for the InGaN QW layer revealed that increasing the growth pressure had the effect of increasing InN incorporation on the semi-polar facets, while increasing the growth temperature improves the uniformity of light emission from the QWs on the non-polar facets