We report an approach to improve the photoelectrochemical water splitting (PEC-WS) performance using GaN-nanowire (NW) bundles (GNW-BDLs) as the photoanode material. The bundles were formed by dipping GaN NWs with...

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The performance of photoelectrochemical water splitting (PEC-WS) over time was drastically improved using new carrier-guiding semiconductor nanostructures, namely InGaN/GaN core-shell nanowires (CSNWs) with a protruding core, as a photocathode (PC)...

We report the high solar-to-hydrogen conversion efficiency (STH) and long-term stability of a photoelectrochemical water-splitting (PEC-WS) system using GaN pyramidal dots (PDs) coated with oxidized tungsten sulfide (OTS) as the...

We report the improvement in photoelectrochemical water splitting (PEC-WS) by controlling migration kinetics of photo-generated carriers using InGaN/GaN hetero-structure nanowires (HSNWs) as a photocathode (PC) material. The InGaN/GaN HSNWs were formed by first growing GaN nanowires (NWs) on an Si substrate and then forming InGaN NWs thereon. The InGaN/GaN HSNWs can cause the accumulation of photo-generated carriers in InGaN due to the potential barrier formed at the hetero-interface between InGaN and GaN, to increase directional migration towards electrolyte rather than the Si substrate, and consequently to contribute more to the PEC-WS reaction with electrolyte. The PEC-WS using the InGaN/GaN-HSNW PC shows the current density of 12.6 mA/cm2 at −1 V versus reversible hydrogen electrode (RHE) and applied-bias photon-to-current conversion efficiency of 3.3% at −0.9 V versus RHE. The high-performance PEC-WS using the InGaN/GaN HSNWs can be explained by the increase in the reaction probability of carriers at the interface between InGaN NWs and electrolyte, which was analyzed by electrical resistance and capacitance values defined therein.