  We report on the local electronic structure of oxygen incorporated FeTe and
FeSe films and how this relates to superconductivity observed in these films.
In the case of FeTe, intially grown films are measured to be
non-superconducting, but become superconducting following oxygen incorporation.
In FeSe the opposite happens, initially grown films are measured to be
superconducting, but experience a quenching of superconductivity following
oxygen incorporation. Total Fluorescence Yield (TFY) X-ray absorption
experiments show that oxygen incorporation changes the initial Fe valence state
in both the initially grown FeTe and FeSe films to mainly Fe3+ in the oxygen
incorporated films. In contrast we observe that while Te moves to a mixed
Te0/Te4+ valence state, the Se always remains Se0. This work highlights how
different responses of the electronic structure by the respective chalcogenides
to oxidation could be related to the mechanisms which are inducing
superconductivity in FeTe and quenching superconductivity in FeSe.
