From powder to nanowire: a simple and environmentally friendly strategy for optical and electrical GaN nanowire films

Abstract

Gallium nitride nanowires (GaN NWs) were successfully grown on silicon substrates deposited with a thin gold film by plasma-assisted hot filament chemical vapor deposition (CVD), where GaN powder was used as the Ga source and nitrogen and hydrogen gases were used for the reactive gases. The diameters of synthesized GaN NWs are in a range of 40–150 nm and the lengths of some of the NWs are up to over 10 μm. The GaN NWs crystallize in a wurtzite structure and they are grown in alignment or bending modes depending on the growth conditions. The photoluminescence spectra exhibit five emission bands at about 379, 396, 467, 481 and 491 nm, which are related to the band edge emission, defects and impurities of GaN NWs, respectively. Furthermore, the excellent field emission (FE) properties of GaN NWs were observed, and the FE results reveal that the GaN NWs have a low turn-on field of 1.66 V μm−1. It supplies a simple strategy to prepare GaN NW films for optical and electrical applications.