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Electronic and thermoelectric transport in highly heterogeneous nanometerials and devices

Supervisor: Dr Phytos Neophytou

Two thirds of all energy we use is lost into heat during conversion processes, a loss which puts enormous pressure on the plant, the use of fossil fuels, and energy sustainability. Thermoelectric materials convert waste heat into electricity and could provide a solution towards this problem [1]. Complex electronic structure materials, as well as nanostructured materials, once properly designed, can boost the thermoelectric efficiency to levels that allow large scale technological implementation [2]. Thus, over the last several years, large efforts are put in the design of highly heterogeneous nanostructured materials with high performance improvements, based on inexpensive raw materials as well. In these novel material designs, disorder is introduced hierarchically at the atomic scale, the nanoscale (<10nm) and the macroscale. A large variety of materials, such as half-Heuslers, Si, BiTe, PbTe, SnSe and their alloys, polymer compounds, etc., are now under intense experimental investigations [1].

This project studies and designs through theory and large scale simulations, the thermoelectric properties of such materials, their ability to conduct electrons [3], and their ability to stop the flow of heat [3], leading to high conversion efficiencies. Successful high efficiency material designs would enable technological applications that vary from large scale power generation (heat from industrial process, car exhausts, etc.), to micro-scavenging, i.e. to realize self-powered sensor devices that enable the Internet of Things.

Neophytou thermoelectrics

References

[1] D. Beretta et al., Materials Science and Engineering: R: Reports, (2018)

[2] K. Biswas, J. He, I. D. Blum, C.-I. Wu, T. P. Hogan, D. N. Seidman, V. P. Dravid, and M. G. Kanatzidis, Nature,489, 414, (2012).

[3] V. Vargiamidis and N. Neophytou, Phys. Rev. B, 99, 045405, (2019)

[4] D. Chakraborty, S. Foster, and N. Neophytou, Phys. Rev. B, 98, 115435, (2018)