Optical XAFS of ZnO Nanowires at the Zn K-Edge and Related Phenomena

We report x-ray excited optical luminescence (XEOL) from one-dimensional nanostructures of ZnO excited with photon energies across the Zn K-edge. The optical luminescence shows an UV and a green emission band characteristic of near band edge and defect emission, respectively. The optical channels were used in turn to monitor the Zn K-edge XAFS to high k values. The densities of states of oxygen character in the valence band were also studied with x-ray emission spectroscopy (XES). The Zn K-edge decay dynamics was examined with time-resolved x-ray excited optical luminescence.