Nanoscale selective area growth of thick, dense, uniform, In-rich, InGaN nanostructure arrays on GaN/sapphire template

Abstract

Uniform, dense, single-phase, 150 nm thick indium gallium nitride (InGaN) nanostructure (nanorods and nanostripes) arrays have been obtained on gallium nitride templates, by metal organic chemical vapor deposition and nanoscale selective area growth on silicon dioxide patterned masks. The 150 nm thick InGaN nanorods have a perfect hexagonal pyramid shape with relatively homogenous indium concentration up to 22%, which is almost twice as high as in planar InGaN grown in the same condition, and luminesce at 535 nm. InGaN nanostripes feature c-axis oriented InGaN in the core which is covered by InGaN grown along semi-polar facets with higher In content. Transmission electron microscope and sub micron beam X-rays diffraction investigations confirm that both InGaN nanostructures are mostly defect free and monocrystalline. The ability to grow defect-free thick InGaN nanostructures with reduced polarization and high indium incorporation offers a solution to develop high efficiency InGaN-based solar cells.