| Abstract Scope |
Nano-based thermoelectric converters exhibit a major stability advantage for long-term operation, compared to many other competing conversion methods. Yet, such converters usually operate under high temperatures and large temperature gradients conditions, which can affect the stability of the nano-features embedded in the bulk thermoelectric main phases.
In the current research, the thermodynamic nano-features generation approach in bulk thermoelectric materials, was considered, using controlled phase separation conditions according to the relevant phase diagrams. Specific systems showing a miscibility gap, including the PbTe-GeTe and PbTe-PbS systems, were heat treated under various required conditions for promoting spinodal decomposition and nucleation and growth reactions. High ZT values of up to 2.2 were obtained due to combined optimal doping and sub-micron phases' decomposition features. Such features were found as thermodynamically stable under long-term investigation at temperatures up to 400oC, resulting in almost unchanged figure of merit values after the various investigated heat treatment durations.
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