Wydarzenia w AGH

Wykład zatytułowany „From electronic structure engineering to thermoelectric generators” wygłosi prof. Krzysztof Wojciechowski z Wydziału Inżynierii Materiałowej i Ceramiki AGH.

Miejsce: ACMiN AGH (Kraków, ul. Kawiory 30, bud. D-16, sala 1.02A)

Abstract

The development of technology for the production of a new class of thermoelectric converters with enhanced efficiency of energy conversion, cheaper in production, and more environmentally friendly than commercial modules is strongly desired. For this aim, we have developed novel strategies for the achievement of a high average thermoelectric figure of merit ZTaver based on advanced electronic structure and phonon engineering.

Our team developed a new concept of Double Tuned Functionally Graded Thermoelectric Material (DT-FGTM) which was experimentally tested on PbTe and Bi2Te3 solid solutions. Our approach assumes the simultaneous tuning of two electronic parameters e.g. the bandgap Eg and the Fermi level EF to gain a high averaged figure of merit ZTave over the operational temperature range. We have proved that within the developed DT-FGTM approach high efficiency in energy conversion, at least ~15 % can be achieved.

The second approach within this theory concerns the composites made of at least two semiconductors/metals with Attuned Electronic Structure and Mismatched Phonon Structure AES-MPS. In particular, a composite consisting of Mn and Sb co-doped GeTe as a matrix and WC as a dispersed phase was prepared, and its structural and TE properties were investigated. The simultaneous effect of enhanced thermoelectric power factor and reduced phonon thermal conductivity results in an extraordinarily high figure of merit ZT of 1.93 at 773K. The best materials were selected for the construction of prototypical thermoelectric converters. The determined power density exceeds 2.4 kW/m2 which makes these elements very attractive for practical applications.