Comparison of GaN nanowires grown on c-, r- and m-plane sapphire substrates

TL;DR

This study compares the growth and properties of GaN nanowires on different sapphire substrates, analyzing how various growth parameters influence nanowire orientation, morphology, and optical characteristics.

Contribution

It provides a systematic analysis of how substrate orientation and growth conditions affect GaN nanowire growth and properties, which was not comprehensively studied before.

Findings

Nanowires grow along specific axes depending on substrate orientation.

Growth parameters significantly influence nanowire morphology and orientation.

Characterization confirms crystalline quality and optical properties.

Abstract

Gallium nitride nanowires were grown on c-plane, r-plane and m-plane sapphire substrates in a showerhead metalorganic chemical vapor deposition system using nickel catalyst with trimethylgallium and ammonia as precursors. We studied the influence of carrier gas, growth temperature, reactor pressure, reactant flow rates and substrate orientation in order to obtain thin nanowires. The nanowires grew along the <10-11> and <10-10> axes depending on the substrate orientation. These nanowires were further characterized using x-ray diffraction, electron microscopy, photoluminescence and Raman spectroscopy.