Atomic local structure around Cu in CuxCd1-xTe thin films

X-ray absorption spectroscopy (XAS) was used to investigate the local atomi c structure around Cu atoms in CuxCd1-xTe thin films, for x = 10 and 15 at. % nominal Cu concentrations. X-ray absorption near edge spectra (XANES) rev eal a Cu local electronic structure different from that encountered in Cu m etal. X-ray diffraction measurements have shown the presence of a single zi ncblende phase even for 15 at.% nominal Cu concentration. However, X-ray ab sorption fine structure (XAFS) spectra show Cu-Cu distances characteristic of Cu metal clusters, and Cu-Te distances significantly shorter than the Cd Te nearest neighbor distance. These results imply the occurrence of microsc opic phase separation in this material, and significant lattice distortions around the Cu incorporated in the CdTe matrix.