Enhanced water splitting performance of GaN nanowires fabricated using anode aluminum oxide templates

Abstract

Highly ordered GaN nanowires were fabricated using an anodic aluminum oxide (AAO) template.

In(Ga)N Nanostructures and Devices Grown by Molecular Beam Epitaxy and Metal-Assisted Photochemical Etching

“…Typically, the peaks of these four modes appear around 143, 658, 556, and 724 cm −1 , respectively. Xi et al performed a Raman study of GaN nanowires produced on anode aluminum oxide templates [ 81 ]. They allocated the Raman peaks at 143, 556, 568, and 733 cm −1 to the E 2 L , E 1 (TO), E 2 H, and A 1 (LO) modes of first-order phonons, respectively.…”

Recent Progress in Gallium Nitride for Photoelectrochemical Water Splitting

“…Many different morphologies of GaN for PEC water splitting have been proposed. Xi and co-workers used metal-organic chemical vapor deposition (MOCVD) to fabricate GaN nanowires, and it has obtained high photocurrent density value at an applied bias voltage from À1 to 1 V [73]. Its morphology was shown in Figure 4a.…”

“…(a and c) Reproduced from Ref. [73] with permission from The Royal Society of Chemistry. (b and d) Reproduced from Ref.…”

“…(c) Structure schematic of InGaN/GaN MQW on n-GaN hollow NWs, (d) comparison of IPCE values for InGaN/GaN MQWs grown on solid and hollow n-GaN nanowires[74]. (a and b) Reproduced from Ref [73]. with permission from The Royal Society of Chemistry.…”

Stable Photoelectrochemical Water Splitting Using p–n GaN Junction Decorated with Nickel Oxides as Photoanodes

“…This characteristic makes it possible to use the Ga x In 1– x N-based photoelectrodes to drive the overall water splitting under sunlight illumination. − Although the III-nitride semiconductors grown by metal–organic chemical vapor deposition (MOCVD) possess high crystal quality, the PEC performances using the III-nitride-based photoelectrodes still suffer from severe bulk recombination and photocorrosion. In order to minimize the recombination losses, utilizing the geometry structure with lateral size less than the diffusion length of the minority carriers of GaN for PEC water splitting has been studied by several groups. − The nanostructure of GaN photoelectrodes benefit the extraction of the photogenerated carriers, while the drawback is the extra photovoltage loss induced by the excess surface area and/or defects. , Another strategy to address the charge recombination is applying a p–n junction on the photoelectrodes. Some groups have demonstrated on the BiVO4 photoanodes to exhibit a superior charge separation efficiency after employing the p–n junction. − Nevertheless, the typical fabrication process is difficult to precisely control the thickness and doping concentration of these material systems.…”