Large-Area Ordered P-type Si Nanowire Arrays as Photocathode for Highly Efficient Photoelectrochemical Hydrogen Generation

In this Article, we report the successful fabrication of large-area ordered Si nanowire arrays (NWAs) by a cost-effective and scalable wet-etching process in combination with nanospheres lithography technique. The periodical Si NWAs are further investigated as photocathode for water splitting, with excellent hydrogen evolution performances with a maximum photocurrent density of 27 mA cm(-2) achieved, which is similar to 2.5 times that of planar Si and random Si nanowires electrode. The greatly improved PEC performance can be attributed to the patterned and ordered NWs structure as a result of enhancement of the light harvesting as well as charge transportation and collection efficiency.