X-ray absorption and X-ray excited optical luminescence (XEOL) studies of KAu(CN) 2 at the C, N and K K-edge and the Au L 3-edge—comparison with density functional theory (DFT) calculation

Abstract

The optical properties of KAu(CN) 2 in the solid state have been investigated with X-ray excited optical luminescence (XEOL) by tuning the excitation photon energy across the C, N and K K-edge as well as the Au L 3-edge. The photoluminescence exhibits an intense peak at ∼370 nm and two weaker but significantly broader peaks at longer wavelengths (590 and 730 nm). The X-ray absorption near edge structure (XANES) at the C, N and K K-edge recorded with photoluminescence yield (PLY) are inverted while the PLY XANES at the Au L 3-edge exhibits normal behavior. These results are interpreted on the basis of a density functional theory (DFT) calculation of the band structures and the XANES of KAu(CN) 2.