I will describe our recent development of a first principles thermoelectric transport model based on the Boltzmann transport theory and its application to the classic high-performing thermoelectric material PbTe [1,2]. Unlike nowadays standard methods which calculate electron-phonon matrix elements in the entire Brillouin zone using density functional perturbation theory and Wannier/Fourier interpolation [3], our model makes use of deformation potential theory, which dramatically reduces the number of electron-phonon matrix elements that need to be computed. This development is important for narrow-gap semiconductors such as PbTe, where the band structures are often inaccurately captured by density functional theory, and the effects of electron correlations on electron-phonon matrix elements might be necessary to include [4].
Regarding the physical effects, I will show that soft transverse optical modes are the key to the high thermoelectric figure of merit of PbTe: they preserve its high electronic conductivity while suppressing the lattice thermal conductivity [1]. I will also present our recently developed understanding of the role of intervalley scattering in establishing the high thermoelectric figure of merit of p-type PbTe [2,5].
[1] J. Cao, J. D. Querales-Flores, A. R. Murphy, S. Fahy, and I. Savic, Phys. Rev. B, 98, 205202 (2018)
[2] R. D'Souza, J. Cao, J. D. Querales-Flores, S. Fahy, and I. Savic, Phys. Rev. B 102, 115204 (2020)
[3] S. Ponce, E. R. Margine, C. Verdi, and F. Giustino, Comput. Phys. Commun. 209, 116 (2016)
[4] A. R. Murphy, F. Murphy-Armando, S. Fahy, and I. Savic, Phys. Rev. B 98, 085201 (2018)
[5] R. D'Souza, J. D. Querales-Flores, J. Cao, S. Fahy, and I. Savic, ACS Appl. Energy Mater. 5, 7260 (2022)
Dr Ivana Savic joined King's College London in 2022 as a Senior Lecturer in Physics. She obtained her undergraduate degree in Electrical Engineering from the University of Belgrade, Serbia in 2003, and PhD from the University of Leeds, UK in 2006. Her postdoctoral research positions were at the Commission of Atomic Energy, Grenoble, France and the University of California, Davis, USA. Prior to joining King's College London, she led a research team at the Tyndall National Institute, University College Cork, Ireland. Dr Savic’s research focus is the development of theoretical and computational approaches to characterise and predict the transport and ultrafast processes in bulk and nanostructured materials.
I will describe our recent development of a first principles thermoelectric transport model based on the Boltzmann transport theory and its application to the classic high-performing thermoelectric material PbTe [1,2]. Unlike nowadays standard methods which calculate electron-phonon matrix elements in the entire Brillouin zone using density functional perturbation theory and Wannier/Fourier interpolation [3], our model makes use of deformation potential theory, which dramatically reduces the number of electron-phonon matrix elements that need to be computed. This development is important for narrow-gap semiconductors such as PbTe, where the band structures are often inaccurately captured by density functional theory, and the effects of electron correlations on electron-phonon matrix elements might be necessary to include [4].
Regarding the physical effects, I will show that soft transverse optical modes are the key to the high thermoelectric figure of merit of PbTe: they preserve its high electronic conductivity while suppressing the lattice thermal conductivity [1]. I will also present our recently developed understanding of the role of intervalley scattering in establishing the high thermoelectric figure of merit of p-type PbTe [2,5].
[1] J. Cao, J. D. Querales-Flores, A. R. Murphy, S. Fahy, and I. Savic, Phys. Rev. B, 98, 205202 (2018)
[2] R. D'Souza, J. Cao, J. D. Querales-Flores, S. Fahy, and I. Savic, Phys. Rev. B 102, 115204 (2020)
[3] S. Ponce, E. R. Margine, C. Verdi, and F. Giustino, Comput. Phys. Commun. 209, 116 (2016)
[4] A. R. Murphy, F. Murphy-Armando, S. Fahy, and I. Savic, Phys. Rev. B 98, 085201 (2018)
[5] R. D'Souza, J. D. Querales-Flores, J. Cao, S. Fahy, and I. Savic, ACS Appl. Energy Mater. 5, 7260 (2022)
Dr Ivana Savic joined King's College London in 2022 as a Senior Lecturer in Physics. She obtained her undergraduate degree in Electrical Engineering from the University of Belgrade, Serbia in 2003, and PhD from the University of Leeds, UK in 2006. Her postdoctoral research positions were at the Commission of Atomic Energy, Grenoble, France and the University of California, Davis, USA. Prior to joining King's College London, she led a research team at the Tyndall National Institute, University College Cork, Ireland. Dr Savic’s research focus is the development of theoretical and computational approaches to characterise and predict the transport and ultrafast processes in bulk and nanostructured materials.
