Systematic Investigation of the Electronic Structure of Hematite Thin Films

Water photolysis is a key technology to convert solar energy into clean, sustainable fuel. Hematite Fe2O3 thin films are considered as a potential photoanode for this purpose. The performance of hematite-based devices is limited by charge carrier transport and recombination, which are intimately linked to the electronic structure. Investigations of the electronic structure of hematite by photoemission exhibit pronounced differences in the reported spectra. A combination of structural and spectroscopic characterization methods is used to unravel the relation between the crystalline and the electronic structure of hematite thin films, which provides unique fingerprint spectra for different crystalline states. The combination with valence band DOS calculations from literature allows for an assignment of the contribution of iron and oxygen (hybrid-) states to the valence band DOS.