LAUSR

In this work, we present a generic semiclassical approach for theoretically evaluating the impact of bulk trap states on the maximum attainable photovoltage in solar-assisted water-splitting reactions. Our method explicitly considers the charge contribution due to the capture and emission of conduction band electrons and valence band holes by trap states situated in the band gap, integrated within a self-consistent solution procedure for calculating electrostatic and charge transport properties. Utilizing the hematite photoanode as our model system, our approach reveals that bulk trap states may significantly degrade both the maximum attainable photovoltage and the concentration of mobile electrons (majority carriers) in the conduction band. These results suggest that bulk trap states can have two primary consequences in photoanodes. First, they may limit the degree to which a favorable cathodic shift in the photocurrent can be achieved (by lowering the maximum attainable photovoltage). Second, they may i...