ICT2014 Abstracts

There are investigated the vapor-phase condensates of compounds PbTe:Sb(Bi) and solid solutions PbTe-Sb₂(Bi₂)Te₃ with stable n-type of conductivity and high carriers concentration, and the optimum Seebeck coefficient (S), which provide significant thermoelectric power. Condensate obtained by open evaporation in vacuum on fresh chips (0001) mica-muscovite and crystalline sital substrates. There are received influence of technological factors of the vapor deposition, such as composition of the material, the deposition and evaporation temperatures, and the type of substrate on the processes of their formation and thermoelectric properties. It is shown that the structure formed by the Folmer-Weber mechanism with implementation of the stage of nucleation, aggregation and coalescence of nanoclusters, and the dominant process of growth is diffusion in Ostwald approximation. Established more orderly growth of nano-objects on single crystal substrates leads to better performance of thermoelectric material due to high carrier mobility, and hence their high specific conductivity.

In particular, the thermoelectric power (S²σ) of condensates on the fresh chips (0001) mica-muscovite is 21.2 mWt/K²cm for PbTe:Sb with antimony containing of 0.25 at.%. This value is 5.24 mWt/K²cm for the same content of PbTe:Sb on polycrystalline sital substrates. The best results were obtained for solid solutions PbTe-Bi₂Te₃ (~1 mol.% of Bi₂Te₃). For these solid solutions S²σ is 77.2 mWt/K²cm on substrates of mica and 22.1 mWt/K²cm for sital substrates.

This research is sponsored by NATO's Public Diplomacy Division in the framework of “Science for Peace” (NATO.NUKR.SFPP 984536).