Effects of experimental parameters on the growth of GaN nanowires on Ti-film/Si(1 0 0) and Ti-foil by molecular beam epitaxy

Abstract

Gallium nitride (GaN) nanostructures are used in optoelectronic applications due to their unique optical and electronic properties. For some optoelectronic applications and potential photocatalytic systems, the growth of GaN nanowires on metallic substrates instead of expensive single crystalline semiconductors can be beneficial due to specific properties of metals. In this study, GaN nanowire systems were grown on 300 nm Ti-film/Si(100) and Ti-foil by plasma assisted molecular beam epitaxy (PA-MBE) and characterized in situ by Auger electron spectroscopy (AES) and ex situ by scanning electron microscopy (SEM). Effects of (i) the nature of substrate surface, (ii) Ga flux, and (iii) substrate temperature on the growth of GaN nanowires were investigated. Nearly vertical nanowires can be grown on Ti-films covered with amorphous TiOx or TiOxNy, which is formed during the nitridation process. To grow nearly vertical nanowires on Ti-foils, pre-nitridation of the substrate surface was found to be important. The orientation of GaN nanowires grown on nitridated Ti-foil is determined by the grain alignment of the original Ti-foil, however, GaN nanowires grown on nitridated Ti-foils are uniformly oriented to one direction within an individual grain, which is most likely due to the epitaxial relation between the nanowires and the underneath grains of the polycrystalline Ti-foils. Both the orientation and nanowire density vary on different grains.

Nanomaterial Integration in Micro LED Technology: Enhancing Efficiency and Applications

“…The use of nanoscale engineering further improves flexibility in design [42]. GaN and its alloys, such as AlGaN (Aluminum Gallium Nitride) and InGaN (Indium Gallium Nitride), with an emphasis on GaN that directs and governs the micro-LED fabrication process, significantly enhance light emission efficiency [43]. Careful control of the emission wavelength via deliberate modulation of III-Nitride alloy composition is essential for this purpose, in which Gallium Nitride (GaN) takes a lead role [44,45].…”

X-ray scattering study of GaN nanowires grown on Ti/Al2O3 by molecular beam epitaxy

“…TiN is a substrate with a low nucleation rate of GaN NWs, resulting in a density an order of magnitude lower than that of GaN NWs grown on Si(111). TiN layers have been prepared by nitridation of Ti films (Sarwar et al, 2015;Wo ¨lz et al, 2015;Zhao et al, 2016;van Treeck et al, 2018;Mudiyanselage et al, 2020) and Ti foils (Calabrese et al, 2016;May et al, 2016;Calabrese et al, 2017;Ramesh et al, 2019Ramesh et al, , 2020Mudiyanselage et al, 2020), as well as by directly sputtering TiN x on Al 2 O 3 (Auzelle et al, 2021).…”

Geometrical Selection of GaN Nanowires Grown by Plasma-Assisted MBE on Polycrystalline ZrN Layers

“…There is increasing interest in growing GaN NWs on metal substrates [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. Such substrates exhibit excellent electrical and thermal conductivities as well as a high optical reflectance.…”