Speaker
Description
Copper vanadates have recently shown promise as photoanodes for water-splitting photoelectrochemical cells. However, studies revealed that their performance is severely limited. We study, both experimentally and computationally, the electronic structure, excitonic effects and optical properties of β-Cu2V2O7. To achieve an accurate description of the properties of this complex oxide, we perform calculations within the framework of the Bethe-Salpeter equation and the QSGW method, while including effects of magnetic ordering, nuclear quantum motion and thermal vibrations. We find strongly bound excitons, that can affect the photoelectrochemical efficiency, and explain therewith the lower efficiencies compared to those implied by the band gap alone.