Li Shi

Laboratory of Quantum Materials for Sustainable Technologies

Prof. Shi is an active teacher-scholar in materials physics and thermal science. He has made seminal contributions to the science and engineering of ultrahigh-thermal conductivity materials. His research group has pioneered a set of unique experimental methods based on electro-thermal microbridge platforms, inelastic light scattering, and scanning probe microscopy to discover size scaling behaviors and substrate effects on thermal transport in carbon nanotubes (CNTs), graphene and hexagonal boron nitride (h-BN), and three-dimensional architectures of these low-dimensional materials for thermal management. He led a multidisciplinary research team from multiple institutions to demonstrate boron arsenide (BAs) as the first known bulk semiconductor with an unusual high thermal conductivity, which defies the conventional criteria requiring strongly bonded light elements to achieve a high lattice thermal conductivity. This work on BAs and their subsequent study of semi-metallic tantalum nitride (TaN) have helped to establish a band engineering paradigm of ultrahigh-thermal conductivity compounds made of both light and heavy elements.

In addition, their research has advanced the fundamental understanding of coupled heat, charge, and spin transport phenomena in thermoelectric, topological, and spintronic materials. These discoveries include significant electronic thermal transport in conducting polymers, surface states and ambipolar thermoelectric transport in transition metal chalcogenides, gapped excitations of lattice and spin dynamics in incommensurate chimney ladder and spin ladder compounds, and different length scales for magnon spin and energy relaxation and a spin Peltier magnetoresistance in ferromagnetic garnets.

These discoveries have helped industry to make informed decisions on emerging electronic, energy, and thermal management materials. In addition, their adventure into nanotechnologies for targeted drug delivery and biomedical imaging has produced noteworthy results, such as shape-specific polymeric drug carriers manufactured by nano-imprint lithography.

Dr. Shi’s accomplishments have been recognized by the Touloukian Award in Thermophysical Properties, the Heat Transfer Memorial Award in Science, the O’Donnell Award in Engineering, and the Invitation Fellowship for Research in Japan.

Selected Publications

Full Publication List on Google Scholar & Web of Science

1. H.-K. Lyeo, A. A. Khajetoorians, L. Shi, K. P. Pipe, R. J. Ram, A. Shakouri, C. K. Shih, "Profiling the Thermoelectric Power of Semiconductor Junctions with Nanometer Resolution," Science 303, 816-818 (2004)

2. J. H. Seol, I. Jo, A. L. Moore, L. Lindsay, Z. H. Aitken, M. T. Pettes, X. Li, Z. Yao, R. Huang, D. Broido, N. Mingo, R. S. Ruoff,  L. Shi, “Two-Dimensional Phonon Transport in Supported Graphene,” Science 328, 213-216 (2010)

3. M. M. Sadeghi, I. Jo, L. Shi, “Phonon-Interface Scattering in Multi-layered Graphene on an Amorphous Support,” Proceedings of National Academy of Sciences 110, 16321–16326 (2013)

4. A. Weathers, Z. U. Khan, R. Brooke, D. Evans, M. T. Pettes, J. W. Andreasen, X. Crispin, L. Shi, “Significant Electronic Thermal Transport in the Conducting Polymer Poly(3,4-ethylenedioxythiophene) (PEDOT),” Advanced Materials 27, 2101–2106 (2015)

5. X. Chen, A. Weathers, J. Carrete, S. Mukhopadhyay, O. Delaire, D. A. Stewart, N. Mingo, S. N. Girard, J. Ma, D. L. Abernathy, J. Yan, R. Sheshka, D. P. Sellan, F. Meng, S. Jin, J. Zhou, L. Shi, “Twisting Phonons in Complex Crystals with Quasi-One-Dimensional Substructures,” Nature Communications 6, 6723 (2015)

6. I. Kholmanov, J. H. Kim, E. Ou, R. S. Ruoff, and L. Shi, “Continuous Carbon Nanotube–Ultrathin Graphite Hybrid Foams for Increased Thermal Conductivity and Suppressed Subcooling in Composite Phase Change Materials,” ACS Nano 9, 11699-11707 (2015)

7. K. An, K. S. Olsson, A, Weathers, S. Sullivan, X. Chen, X. Li, L. G. Marshall, X. Ma, N. Klimovich, J. S. Zhou, L. Shi, X. Q. Li, “Magnons and Phonons Optically Driven out of Local Equilibrium in a Magnetic Insulator,” Physical Review Letters 117, 107202 (2016)

8. S. Sullivan, A. K. Vallabhaneni, I. Kholmanov, X. Ruan, J. Murthy, L. Shi, “Optical Generation and Detection of Local Non-equilibrium Phonons in Suspended Graphene,” Nano Letters 17, 2049–2056 (2017)

9. F. Tian, B. Song, X. Chen, N. K. Ravichandran, Y. Lv, K. Chen, S. Sullivan, J. Kim, Y. Zhou, T. - H. Liu, M. Goni, Z. Ding, J. Sun, G. A. G. U. Gamage, H. Sun, H. Ziyaee, S. Huyan, L. Deng, J. Zhou, A. J. Schmidt, S. Chen, C. - W. Chu, P. Y. Huang, D. Broido, L. Shi, G. Chen, Z. Ren, “Unusual High Thermal Conductivity in Boron Arsenide Bulk Crystals,” Science 361, 582 (2018)

10. M. M. Sadeghi, Y. Huang, C. Lian, F. Giustino, E. Tutuc, A. H. MacDonald, T. Taniguchi, K. Watanabe, L. Shi, “Tunable Electron-Flexural Phonon Interactions in Graphene Heterostructures,” Nature 617, 282–286 (2023)

11. S. Sullivan, H. Lee, A. Weathers, L. Shi, “Frequency-dependent Phonon-mediated Unidirectional Magnetoresistance in a Metal on an Insulator with Highly Nonequilibrium Magnons,” Physical Review B 107, L140412 (2023)

12. X, Li, L. Shi, “Open Problems in Transport Physics of Ultrahigh-thermal Conductivity Materials”, Journal of Materials Research (2024)