SO4* complex in CdTe: Infrared absorption spectroscopy and first-principles calculations

A sulfur-oxygen complex in CdTe characterized by IR absorption lines at 1097 and 1108 cm(-1) is studied by means of infrared absorption spectroscopy and first principles theory. Temperature-sensitive measurements performed on samples with different O-16:O-18 isotope ratios show that these lines are due to a split nu(3) stretch vibrational mode of a disturbed sulfate ion (SO24-) transformed under the Al (1097 cm(-1)) and E (1108 cm(-1)) representations of the C-3 nu point group. The nu(1) symmetric stretch, nu(4) bend, and nu(1) + nu(3) combination modes of the ion are also identified. An axially disturbed SO4 located at the Cd vacancy site is proposed as a microscopic model of the complex.

Automated summary

A sulfur-oxygen complex in CdTe has been studied using infrared absorption spectroscopy and first principles theory, revealing characteristic absorption lines at 1097 and 1108 cm(-1). Temperature-sensitive measurements on samples with different isotope ratios confirmed that these lines are related to a split ν(3) vibrational mode of a disturbed sulfate ion, and proposed a microscopic model of the complex. Further analysis also identified other vibrational modes of the ion.