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Dr. Ivana Savić

Biography

I received my undergraduate degree in Electrical Engineering from the University of Belgrade, Serbia in 2003, and PhD from the University of Leeds, UK in 2006. My previous research positions were at the Commission of Atomic Energy, Grenoble, France and the University of California, Davis, USA. In 2012, I was awarded a Science Foundation Ireland (SFI) Starting Investigator grant to set up a new research direction at Tyndall National Institute on the theory and design of thermoelectric materials. With further SFI support through a Principal Investigator grant in 2016, I have established a team consisting of several PhD students, postdoctoral researchers and collaborators working on cutting-edge material design concepts for radically improving thermoelectric efficiency. I am also a funded investigator in the SFI CONNECT Centre for Future Networks and Communications.

Research team website: https://www.ivanasavic.science/

Research Interests

My areas of research include the development of computational approaches to characterise, predict and design thermal, electronic and thermoelectric transport properties of semiconducting and quantum materials, as well as their dynamical response to intense light excitations. The major research topics I have worked on include:

Thermoelectric transport properties of ferroelectric domain walls in GeTe. My team and I have recently pioneered the idea that ferroelectric domain walls in one of the best performing thermoelectric materials, GeTe, are exceptional thermoelectric materials, having larger  thermoelectric power factors than those of the state-of-the-art thermoelectric materials at 300 K, Bi2Te3 alloys. We identified the key reasons for the predicted thermoelectric power factor enhancement of GeTe domain walls: the confinement of free charge carriers at the domain walls and the presence of Van Hove singularities in their band structure near the Fermi level.

Thermoelectric transport properties of IV-VI materials near structural and electronic phase transitions. I have been a major player in the development of an emerging concept that efficient thermoelectrics can be found among materials near structural and electronic instabilities. My team have developed some of the first ab-initio methods to simulate thermoelectric transport close to phase transitions and at high temperatures, which are in excellent agreement with experiments. We were the first to show that the inherent lattice instability in another exceptional thermoelectric material, PbTe, leads to the low lattice thermal conductivity and does not degrade the electronic thermoelectric properties, thus leading to excellent thermoelectric performance. In collaboration with Prof. David Reis from Stanford University and using a combination of ultrafast X-ray experiments and theory, we uncovered the electronic origin of the lattice instability in PbTe. We also showed that the thermoelectric figure of merit of p-type PbTe considerably increases near the Lifshitz electronic phase transition induced by temperature. We are currently investigating the effect of other types of electronic instabilities (e.g. Dirac, Van Hove) on the thermoelectric transport properties of PbTe and related IV-VI materials.

Thermal properties of disordered and nanostructured materials. As a postdoctoral researcher in Grenoble and Davis, I have played a pivotal role in the development of some of the first ab-initio methods to compute lattice thermal conductivity. I have applied these methods to elucidate heat transport mechanisms in isotope-disordered nanotubes and nanostructured Si and Ge-based materials. One of my major contributions was to characterise transport regimes for the entire phonon spectrum in isotope-disordered nanotubes (ballistic, diffusive, localised) and show that the single phonon scattering in the diffusive regime is responsible for the experimentally observed low thermal conductivity. Furthermore, my simulations showed that combining nanostructures of different length scales in Si/SiGe nanodot superlattices (atomic disorder, nanodot size and spacing between them) is the key to scattering phonons of different wavelengths and achieving the experimentally observed low thermal conductivity.

Electronic transport in quantum cascade structures in a magnetic field. I developed the first theoretical and computational models of electronic transport and optical gain in quantum cascade lasers and quantum well infrared photodetectors in a magnetic field.  I explained the influence of electron-phonon and electron-electron scattering mechanisms on their transport and optical properties. I also proposed novel designs of such magnetic field tunable lasers and photodetectors, based on dilute magnetic semiconductors.

Research Grants

  • “Computational modelling and design of efficient MoS2 thermoelectric nanocomposites”, European Union – Horizon 2020 (Marie Curie Actions) and Science Foundation Ireland CONNECT Centre, 01/09/2019-31/08/2021, EUR 116,319.00.
  • “Nanoscale engineering of thermoelectric materials: utilising grain boundaries to optimise the thermoelectric efficiency of Bi2Te3”, Science Foundation Ireland CONNECT Centre, 07/05/2019-31/12/2020, EUR 100,763.33.
  • “Computational design of efficient thermoelectric Bi2Te3 thin films”, Science Foundation Ireland CONNECT Centre, 01/04/2019-31/03/2023, EUR 112,600.00.
  • “Thermoelectric efficiency of IV-VI and V2-VI3 materials driven near phase transitions”, Science Foundation Ireland and Department of Education and Learning Northern Ireland Investigators Programme, 01/09/2016-31/09/2020 (no cost extension until 31/08/2021), EUR 1,428,601.00.
  • “Thermoelectric properties of complex bulk materials from first principles”,  European Union – Horizon 2020 (Marie Curie Actions) and Science Foundation Ireland Starting Investigator Grant, 01/09/2012-01/09/2016 (no cost extension until 01/09/2017), EUR 399,712.00.

Publications

Papers in Peer Reviewed Journals

  • Dangić Ð., Fahy S., Savić I., “Giant thermoelectric power factor in charged ferroelectric domain walls of GeTe with Van Hove singularities”, (2020) accepted for publication in Nature Partner Journal Computational Materials.
  • D’Souza R., Cao J., Querales-Flores J.-D., Fahy S., Savić I., “Electron-phonon scattering and thermoelectric transport in p-type PbTe from first principles”, (2020) Physical Review B, 102 (11), pp. 115204. DOI: 10.1103/PhysRevB.102.115204
  • Querales-Flores J.-D., Aguado-Puente P., Dangić D., Cao J., Chudzinski P., Todorov T. N., Grüning M., Fahy S., Savić I., “Towards temperature-induced topological phase transition in SnTe: A first principles study”, (2020) Physical Review B, 101 (23), pp. 235206. DOI: 10.1103/PhysRevB.101.235206
  • Dangić Ð., Murray É. D., Fahy S., Savić I., “Structural and thermal transport properties of ferroelectric domain walls in GeTe from first principles”, (2020) Physical Review B, 101 (18), pp. 184110. DOI: 10.1103/PhysRevB.101.184110
  • Cao J., Querales-Flores J.-D., Fahy S., Savić I., “Thermally induced band gap increase and high thermoelectric figure of merit of n-type PbTe”, (2020) Materials Today Physics, 12, pp. 100172. DOI: 10.1016/j.mtphys.2019.100172
  • O’Mahony S. M., Murphy-Armando F., Murray É. D., Querales-Flores J.-D., Savić I., Fahy S., “Ultrafast relaxation of symmetry-breaking photo-induced atomic forces”, (2019) Physical Review Letters, 123 (8), pp. 087401. DOI: 10.1103/PhysRevLett.123.087401
  • Querales-Flores J.-D., Cao J., Fahy S., Savić I., “Temperature effects on the electronic band structure of PbTe from first principles”, (2019) Physical Review Materials, 3 (5), pp. 055405. DOI: 10.1103/PhysRevMaterials.3.055405
  • Abu Hamed T et al., “Multiscale in modelling and validation for solar photovoltaics”, (2018) European Physics Journal Photovoltaics, 9, pp. 10. DOI: 10.1051/epjpv/2018008
  • Cao J., Querales-Flores J.-D., Murphy A. R., Fahy S., and Savić I., “Dominant electron-phonon scattering mechanisms in n-type PbTe from first principles”, (2018) Physical Review B, 98 (20), pp. 205202. DOI: 10.1103/PhysRevB.98.205202
  • Murphy A. R., Murphy-Armando F., Fahy S., Savić I., “Acoustic deformation potentials of n-type PbTe from first principles”, (2018) Physical Review B, 98 (8), pp. 085201. DOI: 10.1103/PhysRevB.98.085201
  • Dangić Ð., Murphy A. R., Murray É. D., Fahy S., Savić I., “Coupling between acoustic and soft transverse optical phonons leads to negative thermal expansion of GeTe near the ferroelectric phase transition”, (2018) Physical Review B, 97 (22), pp. 224106. DOI: 10.1103/PhysRevB.97.224106
  • Murphy R. M., Murray É. D., Fahy S., Savić I., “Ferroelectric phase transition and the lattice thermal conductivity of Pb1−xGexTe alloys”, (2017) Physical Review B, 95 (14), pp. 144302. DOI: 10.1103/PhysRevB.95.144302
  • Jiang M. P., Trigo M., Savić I., Fahy S., Murray É. D., Bray C., Clark J., Henighan T., Kozina M., Chollet M., Glownia J. M., Hoffmann M. C., Zhu D., Delaire 0., May A. F., Sales B. C., Lindenberg A. M., Zalden P., Sato T., Merlin R., Reis D. A., “The origin of incipient ferroelectricity in lead telluride”, (2016) Nature Communications, 7 (1), pp. 12291. DOI: 10.1038/ncomms12291
  • Murphy R. M., Murray É. D., Fahy S., Savić I., “Broadband phonon scattering in PbTe-based materials driven near phase transition by strain or alloying”, (2016) Physical Review B, 93 (10), pp. 104304. DOI: 10.1103/PhysRevB.93.104304
  • Pereira L. F. C., Savić I., Donadio D., “Thermal conductivity of one-, two- and three- dimensional sp(2) carbon”, (2013) New Journal of Physics, 15 (10), pp. 105019. DOI: 10.1088/1367-2630/15/10/105019
  • Savić I., Donadio D., Gygi F., Galli G., “Dimensionality and heat transport in Si-Ge superlattices”, (2013) Applied Physics Letters, 102 (7), pp. 073113. DOI: 10.1063/1.4792748
  • He Y., Savić I., Donadio D., Galli G., “Lattice thermal conductivity of semiconducting bulk materials: atomistic simulations”, (2012) Physical Chemistry Chemical Physics, 14 (47), pp. 16209-16222. DOI: 10.1039/C2CP42394D
  • Pernot G., Stoffel M., Savić I., Pezzoli F., Chen P., Jacquot A., Savelli G., Schumann J., Denker U., Mönch I., Deneke C., Schmidt O. G., Rampnoux J. M., Wang S., Plissonnier M., Rastelli A., Dilhaire S., Mingo N., “Precise control of thermal conductivity at the nanoscale via individual phonon scattering barriers”, (2010) Nature Materials, 9 (6), pp. 491–495. DOI: 10.1038/nmat2752
  • Stewart D. A., Savić I., Mingo N., “First-principles calculation of the isotope effect on boron nitride nanotube thermal conductivity”, (2009) Nano Letters, 9 (1), pp. 81-84. DOI: 10.1021/nl802503q
  • Savić I., Stewart D. A., Mingo N., “Thermal conduction mechanisms in boron-nitride nanotubes: Few-shell versus all-shell conduction”, (2008) Physical Review B, 78 (23), pp. 235434. DOI: 10.1103/PhysRevB.78.235434
  • Savić I., Mingo N., Stewart D. A., “Phonon transport in isotope-disordered carbon and boron-nitride nanotubes: Is localization observable?”, (2008) Physical Review Letters, 101 (16), pp. 165502. DOI: 10.1103/PhysRevLett.101.165502
  • Savić I., Vukmirović N., “Intraband magneto-optical properties of magnetic quantum dots”, (2007) Physical Review B, 76 (24), pp. 245307. DOI: 10.1103/PhysRevB.76.245307
  • Savić I., Vukmirović N., Ikonić Z., Indjin D., Kelsall R. W., Harrison H., Milanović V., “Density matrix theory of transport and gain in quantum cascade lasers in a magnetic field”, (2007) Physical Review B, 76 (16), pp. 165310. DOI: 10.1103/PhysRevB.76.165310
  • Vukmirović N., Ikonić Z., Savić I., Indjin D., Harrison P., “A microscopic model of electron transport in quantum dot photodetectors”, (2006) Journal of Applied Physics, 100 (7), pp. 074502. DOI: 10.1063/1.2354321
  • Savić I., Ikonić Z., Vukmirović N., Indjin D., Harrison P., Milanović V., “Design of a ZnMnSe/ZnMgSe spin-polarized terahertz quantum cascade laser tunable by magnetic field”, (2006) Applied Physics Letters, 89 (1), pp. 011109. DOI: 10.1063/1.2219423
  • Savić I., Ikonić Z., Milanović V., Vukmirović N., Jovanović V. D., Indjin D., Harrison P., “Electron transport in quantum cascade lasers in a magnetic field”, (2006) Physical Review B, 73 (7), 075321. DOI: 10.1103/PhysRevB.73.075321
  • Savić I., Milanović V., Vukmirović N., Jovanović V. D., Ikonić Z., Indjin D., P. Harrison, “Magnetic field tunable terahertz quantum well infrared photodetector”, (2005) Journal of Applied Physics, 98 (8), pp. 084509. DOI: 10.1063/1.2085309
  • Savić I., Milanović V., Ikonić Z., Indjin D., Jovanović V. D., Harrison P., “Diluted magnetic semiconductor quantum-well structures for magnetic field tunable far-infrared/terahertz absorption”, (2004) IEEE Journal of Quantum Electronics, 40 (11), pp. 1614-1621. DOI: 10.1109/JQE.2004.836469

Refereed conference publications

  • Harrison P., Indjin D., Savić I., Ikonić Z., Evans C. A., Vukmirović N., Kelsall R. W., McTavish J., Jovanović V. D., Milanović V., “On the coherence/incoherence of electron transport in semiconductor heterostructure optoelectronic devices”, (2008) Proceedings of SPIE, 6909, pp. 690912. DOI: 10.1117/12.762648
  • Savić I., Ikonić Z., Vukmirović N., Indjin D., Harrison P., Milanović V., “Lasing in spin-polarized terahertz quantum cascade structures”, (2007) Physica Status Solidi C, 3 (12), pp. 4401-4404. DOI: 10.1002/pssc.200672854
  • Vukmirović N., Ikonić Z., Savić I., Indjin D., Harrison P., “Theoretical modeling of electron transport in InAs/GaAs quantum dot superlattices”, (2006) Physica Status Solidi C, 3 (11) pp. 3770-3773. DOI: 10.1002/pssc.200671550
  • Savić I., Harrison P., Milanović V., Indjin D., Ikonić Z., Jovanović V. D., “Quantum cascade lasers in magnetic field: An active region model”, (2005) Physica Status Solidi B, 242 (9), pp. 1812-1816.  DOI: 10.1002/pssb.200461758
  • Harrison P., Indjin D., Jovanović V. D., Mircetić A., Ikonić Z., Kelsall R. W., McTavish J. P., Savić I., Vukmirović N., Milanović V., “A physical model of quantum cascade lasers: application to GaAs, GaN and SiGe devices”, (2005) Physica Status Solidi A, 202 (6), pp. 980-986. DOI: 10.1002/pssa.200460713
  • Harrison P., Indjin D., Jovanović V. D., Mircetić A., Ikonić Z., Kelsall R. W., McTavish J. P., Savić I., Vukmirović N., Milanović V., “Carrier dynamics in quantum cascade lasers”, (2005) Acta Physica Polonica A, 107 (1), pp. 75-81. DOI: 10.12693/APhysPolA.107.75
  • Harrison P., Jovanović V. D., Erić M., Vukmirović N., Savić I., Mircetić A., Radovanović J., McTavish J. P., Evans C., Ikonić Z., Kelsall R. W., Milanović V., Indjin D., “Physical model and scattering dynamics engineering for intersubband lasers and photodetectors”, (2005) Conference on Optoelectronic and Microelectronic Materials and Devices, Proceedings, pp. 351-355. DOI: 10.1109/COMMAD.2004.1577563

Professional Activities

Honours and awards

  • GW Carter Prize for the best published student paper at the School of Electronic and Electrical Engineering, University of Leeds, UK, 2005.
  • Overseas Research Scholarship, University of Leeds, UK, 2003-2006.
  • Top student graduated from the School of Electrical Engineering, University of Belgrade, Serbia, 2003.
  • Royal Norwegian Government Award for outstanding academic results during my undergraduate studies at University of Belgrade, Serbia, 2001.

Professional memberships

  • American Physical Society
  • Materials Research Society
  • American Chemical Society

Conference organisation

  • Psi-k Conference Symposium “New Developments in First-Principles Calculations of Charge and Heat Transport”, Switzerland, 2021.
  • Virtual American Physical Society March Meeting Symposium “Electrons, Phonons, Electron Phonon Scattering and Phononics”,  2021.
  • American Physical Society March Meeting Symposium “Electrons, Phonons, Electron Phonon Scattering and Phononics”,  Boston, USA, 2020.
  • Materials Research Society Spring Meeting Symposium “Nanoscale Heat Transport: Fundamentals”, Phoenix, USA, 2019.
  • European Materials Research Society Spring Meeting Symposium “Nanostructures for Phononic Applications”, Strasbourg, France, 2018.
  • IEEE Nano Symposia “Nanophononics” and “Material Design for Energy Harvesting and Storage”, Cork, Ireland, 2018.
  • Stephen Fahy’s 60th Birthday Conference, Cork, Ireland, 2018.
  • International Workshop on Thermoelectric Materials, Cork, Ireland, 2017.
  • Tutorial preceding Materials Research Society Symposium “Nanoscale Heat Transport: From Fundamentals to Applications”, Phoenix, USA, 2017.

Reviewing

Nature, Scientific Reports, Physical Review Letters, X, B, Applied and Research, Applied Physics Letters, Journal of Applied Physics, Journal of Physics Condensed Matter, Nanotechnology, New Journal of Physics, Nano Letters, ACS Applied Energy Materials, ACS Applied Materials and Interfaces, Journal of Physical Chemistry.

Public engagement

  • Judge of an innovation competition TechnoDen for transition year high school students, 2019.
  • Talk on my research activities for the first year undergraduate physics students at University College Cork, 2018.

Contact details

Dr. Ivana Savić, Staff Researcher, Tyndall National Institute, Dyke Parade, Cork, Ireland.

Email: ivana.savic@tyndall.ie Tel: +353 21 234 6632