Composition of PbTe oxides obtained by different methods

The widespread use of PbTe nanocomposites requires knowledge regarding the composition of their grain boundaries. Cathodoluminescence (CL), TOF-SIMS and Rutherford backscattering spectroscopy (RBS) were used to explore the composition of surface layers formed via thermal, electrochemical, and wet chemical oxidation of lead telluride. Surface layers obtained by these methods contained components with different degrees of oxidation. RBS and CL results show that thermal and anodic oxidation produced ternary PbTeO3 and Pb2TeO4 oxides, respectively. For the chemical oxide we observed a substantially lower concentration of oxygen described by PbO1−xTeO2−x, a significant amount of non-oxidized PbTe ions detected by SIMS, and low CL stability under electron beam radiation. Thus, the chemical oxide is likely a mixture of binary suboxides.