Review of Laser-Based Surface Nanotexturing for Enhanced Light Absorption and Photoelectrochemical Water Splitting

Commercialization of photoelectrochemical (PEC) water-splitting technology is hindered by the slower kinetics of oxygen evolution in the currently available photoanodes. Light absorption, charge-separation, and charge-transfer efficiencies determine the kinetics of the oxygen evolution reaction (OER) at semiconductor photoanode surfaces. All these parameters can be maximized by nanotexturing the photoanode surface through morphological (cones, pyramids, grids, etc.) control and crystallographic (facets) orientation. The primary objective of texturing on conducting substrates is to improve the photoconversion efficiency in PEC devices through an increased surface area and light absorption. Laser-assisted ablation and melt-fusion additive techniques allow for rapid iteration of morphological architecture designs for optimized light absorption properties. This work reviews various ultrafast laser techniques employed for fabricating nanotextured surfaces and their impact on PEC performance. Compared with conventional electrode fabrication techniques, laser-based surface nanotexturing techniques provide a cost-effective, rapid design, and validation method for the research and development of photoelectrochemical water splitting technologies.