The oxidation of PbTe(100) surface in dry oxygen

The oxidation of PbTe(100) surface in dry oxygen was studied by means of XPS. The appearance of a Te+4 component in the Te 3d spectra and an additional component shifted 1.1 eV towards higher binding energies in the Pb 4f spectra was observed. It was revealed that the oxidation mechanism does not change in the range of oxygen exposure 1011–1015 L. The oxidation product stoichiometry is close to PbTeO3. Quantum chemical modelling of the interaction of the small cluster (PbTe)4 with one oxygen molecule was performed by employing the hybrid DFT B3LYP method. It was revealed that PbO (2.22–2.43 Å) and TeO (1.97 Å) bonds are formed during the energetically favourable chemisorption process, giving rise to the increase of Pb and Te effective Mulliken charges by +0.18–0.31e and +1.11e, respectively. These changes are in good correlation with the observed binding energies for additional components in the XPS spectra of the oxidized surface. Copyright © 2004 John Wiley & Sons, Ltd.