LAUSR

Manifold morphology of GaN nanowires (NWs) are fabricated using Halide chemical vapour deposition (HCVD) on n-Si (111) substrate and demonstrated as promising photoelectrode for photo-electrochemical (PEC) water splitting application. We report, substantial enhancement in photocurrent for vertically grown GaN NWs on buffer layer as compared to other counterparts such as GaN whisker, tapered nanostructures and thin films. GaN NWs grown on Si has advantages with the contribution of wide spectral range from ultraviolet to infrared photons absorption and thus, directly involving in PEC reaction. The GaN NWs photoanode has demonstrated with a saturation photocurrent density of 0.55 mA/cm2 under 1 sun illumination which is much greater than its counterparts. The role of buffer layer and carrier density on the PEC performance of vertical grown GaN NWs photoanode is further elucidated. The photo-electrochemical impedance spectroscopy and Mott-Schottky characterizations are employed to further explain the PEC performance of GaN NWs embedded photoanode. Here, diverse GaN nanostructures based photoanode have been examined for the better PEC evaluation in order to support the conclusion. The results may pave for the fabrication of efficient photoelectrode and GaN as protective layer against corrosion towards the better photo-stability in NaOH electrolyte for enhancing the efficiency of water splitting.