COPPER-INDUCED CHANGES IN THE PROPERTIES OF ARSENIC CHALCOGENIDES

The influence of the presence of Cu in the amount between 1% and 6% in arsenic chalcogenide glasses is examined through a study of the elect ronic energy levels by means of x-ray photoelectron and x-ray emission spectroscopy, through an investigation of the low-energy tunneling sy stems by means of phonon echoes at 0.37 K, and through an examination of the photodarkening and the photoinduced dichroism caused by polariz ed Ar+ laser irradiation. Possible links between the various effects a re examined. The Cu atoms become an integral part of the amorphous lat tice structure and strongly influence the photodarkening, but they do not have a significant effect on the tunneling systems or the dichrois m. It is concluded that the tunneling levels and the dichroism involve only local configurations, while the photodarkening involves larger-s cale areas of the lattice. (C) 1998 American Institute of Physics.