Structure of the electrochemically deposited Cu nanoclusters on p-GaAs(100) surface in H2SO4 solution: x-ray absorption analysis

The local 3D structures of electrochemically deposited Cu nanoclusters on p-GaAs(100) with various coverages have been investigated by in-situ surface-sensitive x-ray absorption fine structure (XAFS) analysis. The experimental Cu K-edge XANES of Cu nanoclusters deposited on GaAs surface have been analyzed on the basis of full potential calculations of XANES in the combination with DFT geometry optimization. It has been shown that small partially oxidized Cu nanoclusters are formed when the surface coverage of the Cu overlayer is less than 0.25 monolayer. At higher coverage the Cu microclusters have a fcc structure and are almost not oxidized.