The effects of oxygen vacancies on the electronic properties of V2O5-x

The influences of oxygen vacancies on the electronic properties of V2O5-x have been investigated by photoelectron spectroscopy and first principle calculations. Photoelectron spectroscopic data suggested that the vanadium (V) ions are gradually reduced to lower oxidation states with the increases of oxygen (O) vacancy density. Simultaneously, the formation of O vacancies leads to a decrease in the work function of V2O5-x . Theoretical calculations further prove that the formation of O vacancies would cause a reduction in the charge state of V ions and a decrease of work function. The electronic structures of V ions are strongly modified by the removal of O ions nearby due to electron transfer to the 3d orbitals of the V ions.