The fabrication of GaN/InGaN nano-pyramids photoanode and its enhanced water splitting performance

Abstract

In this paper, we have successfully fabricated a GaN/InGaN nano-pyramids photoanode utilizing the selective area growth (SAG) method. This method has demonstrated a notable improvement in water splitting performance, with a photocurrent enhancement of approximately 1.5 times when compared to the planar GaN/InGaN sample. The remarkable enhancement in water splitting performance can be chiefly attributed to the presence of In-rich InGaN grown on the (10−11) plane and nano-pyramids morphology. The In-content in the pyramid GaN/InGaN structure is approximately 2.25 times higher than that of the planar sample, resulting in increased photon absorption due to a narrower bandgap. Moreover, the nano-pyramids morphology possesses a larger specific surface area, further enhancing its light absorption capacity. These combined advantages significantly contribute to the outstanding improvement in water splitting performance observed in the pyramid GaN/InGaN structure. Our work introduces a novel approach to harnessing GaN materials for highly efficient water splitting applications.