СЕМИНАР: Др Ивана Савић

У оквиру СЦЛ семинара Центра за изучавање комплексних система, у среду, 13. јуна у 14 часова у читаоници библиотеке „Др Драган Поповић“, др Ивана Савић (Тиндал национални институт, Корк, Ирска) ће одржати предавање:

Electronic and Thermoelectric Transport in PbTe: Insights from First Principles Calculations


Thermoelectric materials could play an important role in the development of energy harvesting technologies due to their ability to convert waste heat into electricity [1]. It is challenging to control and enhance the efficiency of thermoelectric energy conversion in a material because of the conflicting requirements for the desired physical properties i.e. high electrical conductivity and low thermal conductivity. Exploiting the fascinating properties of materials near soft mode phase transitions is an emerging concept in the quest to increase thermoelectric efficiency [2,3]. The underlying idea is that soft phonon modes lead to intrinsically low thermal conductivity, while possibly preserving high electronic conductivity. In this talk I will focus on the unusual electronic transport properties of n-type PbTe, which is a classic thermoelectric material that exists near a soft optical mode phase transition. Our first principles calculations show that most scattering mechanisms in PbTe are very weak, with the exception of that due to polar optical phonons [4,5]. Our results suggest that good thermoelectric materials may be found among weakly polar materials with symmetry forbidden scattering mechanisms.

[1] G. J. Snyder and E. S. Toberer, Nat. Mater. 7, 105 (2008).
[2] L.-D. Zhao et al, Nature 508, 373 (2014).
[3] R. M. Murphy, E. D. Murray, S. Fahy, and I. Savic, Phys. Rev. B 93, 104304 (2016); Phys. Rev. B 95, 144302 (2017).
[4] A. R. Murphy, F. Murphy-Armando, S. Fahy, and I. Savic, submitted.
[5] J. Cao, J. D. Querales-Flores, A. R. Murphy, S. Fahy, and I. Savic, in preparation.