Comparison of oxidation processes in binary selenides and tellurides

Abstract

To predict the grain boundaries composition of the nanocomposite thermoelectric IV–VI devices the oxidation processes in PbTe, SnTe, PbSe, SnSe and in some their solid solutions were studied. The initial oxidation stages were investigated by applying the potentiostatic anodic scan. The Auger electron spectroscopy, cathodoluminescence and X‐ray diffraction were used to characterize the composition of the anodic and thermal oxides films. The obtained results demonstrate that the oxidation processes and the oxide composition are near the same at the substitution in the chalcogen sublattice (Te → Se), but they are strongly changed at the substitution in the metal sublattice (Pb → Sn). Under the same growing conditions, the grain boundaries will consist mainly of an amorphous tin oxide in SnTe and SnSe nanocomposites, and the ternary oxide forms the grain boundaries in PbTe and PbSe nanocomposites. In the solid solutions with the Sn occurrence in the metal sublattice tin oxidation becomes a prevailing process, even in case of low tin content. Copyright © 2016 John Wiley & Sons, Ltd.