Enhancement in the Performance of Ultrathin Hematite Photoanode for Water Splitting by an Oxide Underlayer

A 2-nm thick Nb2O5 underlayer deposited by atomic layer deposition increases the charge separation efficiency and the photovoltage of ultrathin hematite films by suppressing electron back injection. Absorbed photon-to-current efficiencies (APCE) as high as 40%, which are one of the highest ever reported with hematite photoanodes, are obtained at 400 nm at +1.43 V vs. RHE. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.