Silicon based MIS photoanode for water oxidation: A comparison of RuO2 and Ni Schottky contacts

• Published in: Applied surface science Vol. 461; pp. 48 - 53
• Main Authors: Mikolasek, Miroslav, Frohlich, Karol, Husekova, Kristina, Racko, Juraj, Rehacek, Vlastimil, Chymo, Filip, Tapajna, Milan, Harmatha, Ladislav
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-12-2018
• Subjects: Fermi level pinning; MIS junction; Photoanode; RuO2; Water oxidation; RuO2; MIS junction; Ni; Photoanode; Water oxidation; Fermi level pinning
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2018.04.234

•Ruthenium oxide suggested as a transparent catalytic gate for MIS photoanode.•Lower Fermi level pinning observed for ruthenium oxide compared to Ni MIS structure.•Photovoltage of 0.46 V was achieved at ∼1×sun illumination.•Low overpotential 0.12 V required for 10 mA/cm2 photoanode current in 1 M KOH.
This paper presents an electrical and photoelectrochemical comparison of MIS photoanodes with a metal organic chemical vapor deposited RuO2 layer and evaporated Ni layer to provide a deeper insight into the interface properties of such structures. The unique properties of RuO2 such as high transparency, high conductance, high catalytic activity, and high work function make this material an excellent candidate for a Schottky contact of MIS photoanodes for water splitting. In contrast to the Ni-based MIS structure, no Fermi level pinning was observed when RuO2 was used. This allowed achieving a high measured photovoltage of 0.46 V compared to 0.3 V for a Ni based structure. The ability to achieve the high photovoltage by utilization of RuO2 catalyst is an important achievement for fabrication of high performing MIS structures.