Controlled Growth of Ordered III-Nitride Core–Shell Nanostructure Arrays for Visible Optoelectronic Devices

Abstract

We demonstrate the growth of ordered arrays of nonpolar \(\{ 10\bar{1}0\} \) core–shell nanowalls and semipolar \( \{ 10\bar{1}1\}\) core–shell pyramidal nanostripes on c-plane (0001) sapphire substrates using selective-area epitaxy and metal organic chemical vapor deposition. The nanostructure arrays are controllably patterned into LED mesa regions, demonstrating a technique to impart secondary lithography features into the arrays. We study the dependence of the nanostructure cores on the epitaxial growth conditions and show that the geometry and morphology are strongly influenced by growth temperature, V/III ratio, and pulse interruption time. We also demonstrate the growth of InGaN quantum well shells on the nanostructures and characterize the structures by using micro-photoluminescence and cross-section scanning tunneling electron microscopy.