Proceedings

EPJ B Highlight - Helping turn waste heat into electricity

The resonant structure of electron scattering on the bismuth lattice.

How the collective motion of electrons interacting with crystal atoms can be fine-tuned to harvest excess heat

At the atomic level, bismuth displays a number of quirky physical phenomena. A new study reveals a novel mechanism for controlling the energy transfer between electrons and the bismuth crystal lattice. Mastering this effect could, ultimately, help convert waste heat back into electricity, for example to improve the overall efficiency of solar cells. These findings have now been published in EPJ B by Piotr Chudzinski from Utrecht University, the Netherlands.

The author investigates the collective motion of electrons in bismuth, which behaves in a fluid manner with waves propagating in it, a phenomenon referred to as a low energy plasmon. Electrons moving throughout the material constantly aim to preserve the same density. Bismuth exhibits two types of electrons--extremely light ones and heavier ones-- moving at different speeds. As a result, an area of less dense electron liquid is formed. In response, electrons move back to compensate at the lower density end. Yet, some of them move faster than others. And a more sparsely dense area appears in another part of the material. And so on and so forth...

This study demonstrates that the low energy plasmons, when tuned to the same wavelength as the lattice vibrations of the bismuth crystal, or phonons, can very efficiently slow lattice motion. In essence, this plasmon-phonon coupling mechanism, once intensified under specific conditions, could be a new way of transferring energy between electrons and the underlying crystal lattice.

One implication is that the plasmon-phonon coupling can help to explain a long-since observed, significant effect in bismuth: the so-called Nernst effect. This occurs when a sample is warmed on one side and subjected to a magnetic field, causing it to produce a significant electrical voltage in the perpendicular direction. Hence it turns heat into useful electricity. Within the new interpretation the Nernst effect scales up with temperature in a manner that is in line with experimental observations in bismuth, lending strong support to the theory.

This was our first experience of publishing with EPJ Web of Conferences. We contacted the publisher in the middle of September, just one month prior to the Conference, but everything went through smoothly. We have had published MNPS Proceedings with different publishers in the past, and would like to tell that the EPJ Web of Conferences team was probably the best, very quick, helpful and interactive. Typically, we were getting responses from EPJ Web of Conferences team within less than an hour and have had help at every production stage.
We are very thankful to Solange Guenot, Web of Conferences Publishing Editor, and Isabelle Houlbert, Web of Conferences Production Editor, for their support. These ladies are top-level professionals, who made a great contribution to the success of this issue. We are fully satisfied with the publication of the Conference Proceedings and are looking forward to further cooperation. The publication was very fast, easy and of high quality. My colleagues and I strongly recommend EPJ Web of Conferences to anyone, who is interested in quick high-quality publication of conference proceedings.

On behalf of the Organizing and Program Committees and Editorial Team of MNPS-2019, Dr. Alexey B. Nadykto, Moscow State Technological University “STANKIN”, Moscow, Russia. EPJ Web of Conferences vol. 224 (2019)

ISSN: 2100-014X (Electronic Edition)

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