Enhancement of the Oxygen Evolution Using a 21-μm-Thin c-Si Photoanode with a Nano-Pyramid Texture

Journal of The Electrochemical Society 164(14) H1129

https://doi.org/10.1149/2.1251714jes

Min-Joon Park, Jong Heo, Hongsub Jee, Jin Young Yu, Sungmin Youn, Kiseok Jeon, Jung-Ho Lee and Chaehwan Jeong

Abstract

It is beneficial to reduce thickness of high-purity of c-Si wafer for cost-effective water splitting system based on silicon photoelectrode. However, a thin Si absorber causes insufficient absorption of light and it should be needed to solve problems. Here, a 21-μm-thin Si photoanode for which a NiOx-coated silicon nanopyramid (SiNP) is employed is presented as a solution. The NiOx/n-SiNP structures improved the light absorption as well as the total number of catalytic sites to enable photo-oxidation reactions. A photocurrent of 7.7 mA/cm2 was generated at the equilibrium potential of the OER (EOER = 1.23 V vs. a reversible hydrogen electrode in a 1 M KOH solution). Also, the photoanode did not show any degradation over the 24 hr of a photoelectrochemical water-oxidation process.