Interfaces between water splitting catalysts and buried silicon junctions

The coupling of water-splitting catalysts to silicon photovoltaics enables direct solar-to-fuel conversion. Critical to the performance of such devices is the use of interfaces to protect silicon from the oxygen-evolving reaction (OER) and at the same time to provide Ohmic contact between the buried silicon junction and the immobilised OER catalyst. Presented herein are guidelines for constructing the Si vertical bar catalyst interface, which is a crucial building block for efficient direct solar-to-fuel conversion devices. We show that fluorinated-tin-oxide is an especially attractive interface for buried-junction devices.