Synthesis and structure of undoped and indium-doped thermoelectric lead telluride nanoparticles.

Undoped and indium (In)-doped lead telluride (PbTe) nanostructures were synthesized via solvothermal/hydrothermal route. The crystalline structure of the as-prepared undoped and In-doped PbTe samples was examined by X-ray diffraction (XRD) which indicated the formation of face-centered single-phase cubic crystal. A first principle calculation on indium doping shows that the indium atoms are more likely to replace lead (Pb) rather than to take the interstitial sites. Laser-induced breakdown spectroscopy (LIBS) analysis confirms that indium is incorporated into the PbTe matrix of the indium-doped PbTe samples. The effects of surfactant and synthesis temperature on the structure and morphology of the undoped PbTe were also investigated; it was found that PbTe nanostructures synthesized with the addition of surfactants exhibited uniform shapes and their size increased with the synthesis temperature.