DESCRIPTION:
We are engaged in materials science and thermal engineering research to control the transport, conversion, and storage of heat, electricity, light, and magnetization in information, energy, and manufacturing technologies. Our research emphasizes fundamental understanding from the macroscale down to the nanoscopic level of quantized energy excitations, including photons, phonons, electrons, and spins. Our approaches include theory-guided synthesis, characterization, and device integration of advanced materials. Our current research efforts are organized along the following three directions:
Heterogeneous Integration of Emerging Electronic and Thermal Management Materials
The electrical energy consumption by semiconductor devices are converted into high-density heating that causes local hot spots and degrades the device performance and thermomechanical reliability. Based on a recent Semiconductor Research Corporation (SRC) report entitled Rebooting the IT Revolution, the energy required for computing at the current benchmark would exceed the world’s energy production by 2040. The report sets a target of three orders of magnitude reduction in the energy consumption for computing a data bit. This target does not exceed the fundamental limit, but will require innovation and implementation of much more energy-efficient electronic materials, devices, and system designs than current-generation technologies.
Along this direction, our research group has advanced the science and engineering of ultrahigh thermal conductivity materials, including carbon nanotubes (CNTs), graphene, hexagonal (h-) and cubic (c-) boron nitride (BN), cubic boron arsenide (c-BAs), and theta-phase tantalum nitride (theta-TaN). We are working actively on heterogeneous integration of c-BAs with lattice-matched III-nitride semiconductors for enhanced electronic and thermal performances. In addition, we investigate field-tunable electronic, thermal, optical, and magnetic properties of two-dimensional (2D) layered materials and pursue heterogeneous integration of these 2D materials into chiplets.
Thermal Science and Engineering of Quantum Materials and Hardware
As semiconductor devices are advancing toward their theoretical limits, progresses are being made to store information in quantum two-level systems to enable secured quantum communication, highly responsive quantum sensing, and quantum computation of complex problems. Among the various grand challenges that need to be overcome for the establishment and deployment of these quantum information technologies, innovative thermal science and engineering solutions with minimum consumption of rare helium isotopes are required for cooling the quantum hardware to an extremely low temperature to prevent thermal smearing of the small energy spacing of the two-level systems. Meanwhile, thermal measurements can provide unique probes of exotic quantum materials that may provide unanticipated changes in direction in quantum hardware design, which are also being explored with the use of coherent excitations of vibrational and spin waves.
One of our current research efforts is focused on modeling and measurement of thermal transport properties and non-equilibrium distributions of temperatures of different quantized energy carriers in the various materials and interfaces of superconducting quantum circuits. Thermalization of superconducting qubits in a dilution refrigerator impacts coherence times and gate fidelity. We aim to advance the frontier in measurements and theoretical computation of quantum hardware thermalization beyond the current practice that relies on phenomenological expression of the electron-phonon and phonon-phonon coupling parameters.
In addition, we are investigating new routes to achieve rapid, large, and reversible electronic switching of heat transport in solids and to lay the groundwork for practical thermal switching devices. Thermal switches based on mechanical actuation or fluid flows are essential components in magnetocaloric and electrocaloric refrigeration cycles. Successful experimental demonstration of high-performance solid-state thermal switching devices can impact a range of technologies, including transformative methods based on exciton condensates for helium-free cryogenic cooling of quantum hardware. Moreover, the basic research in topologically controlled correlated electron and spin physics may lead to enhanced qubits.
Thermal Materials for Decarbonization of Heat and Fuel
A broad spectrum of emerging energy decarbonization technologies requires materials with extraordinary thermal properties at extreme conditions that are often near a structural phase transition. Metallic and ceramic materials with ultrahigh thermal conductivity (k), high phase transition temperatures, high corrosion resistances, and high mechanical strength are indispensable for the manufacturing of efficient high-temperature and high-pressure heat exchangers and heat pumps for decarbonization of industrial heating and enhanced geothermal processes. Meanwhile, long-duration storage of high-temperature heat requires not only high-energy density thermal storage materials, but also high-k materials for rapid charging and discharging of the thermal storage medium and low-k materials for thermal insulation. Ultralow-k thermal insulation materials are also needed to minimize boil off losses in cryogenic storage of liquid hydrogen fuel for hydrogen-fueled vehicle platforms, portable hydrogen powers, and high-volume hydrogen delivery. Moreover, high-temperature and low-k thermal barrier and fire-protection coating materials are critical components for both industrial heating with hydrogen fuel and prevention of battery fires.
Along this direction, we pursue the synthesis, characterization, and thermal transport measurements of theoretically predicted bulk and coating materials with potentially extraordinary thermal behaviors at extreme conditions. These experimental efforts are in close collaboration with theoretical investigations of high-order phonon scattering and electron-phonon scattering in first principles Peierls-Boltzmann transport equation prediction of high-k ceramics, metals, and semimetals. Meanwhile, we aim to advance the theoretical and experimental capabilities for improved prediction of lower bounds to k and search of ultralow k in complex and disordered-ordered materials structures.
PROJECTS:
- Collaborative Research: FuSe: Heterogeneous Integration of III-Nitride and Boron Arsenide for Enhanced Thermal and Electronic Performance
- Post-doctoral and Graduate Student Researchers: Dr. Devika Mehta
Collaboration: Prof. Xiulin Li (UT-Austin), Bing Lv (UT-Dallas), Emmanouil Kioupakis (Michigan), Siddharth Rajan (Ohio State University)
Sponsor: National Science Foundation
Period: 10/2023-09/2026 - Collaborative Research: Thermal Transport via Four-Phonon and Exciton-Phonon Interactions in Layered Electronic and Optoelectronic Materials
- Graduate Student Researcher: Chuting Cai
Collaboration: Prof. Xiulin Ruan (Purdue University)
Sponsor: National Science Foundation
Period: 09/2023-08/2026 - Post-doctoral and Graduate Student Researcher: Dr. Xun Li
Collaboration: Prof. Shyam Shankar
Sponsor: Army Research Office
Period: 07/2023-06/2027 - Manufacturing of High-Strength Nanolattice Coating for Cryogenic Liquid Hydrogen Fuel Storage
- Graduate Student Researchers: Peter Sokalski
Collaboration: Prof. Chih-Hao Chang
Sponsor: The University of Texas at Austin Energy Institute
Period: 05/2023-05/2024 - Tunable Resonant Columbic Heat Transport between Moiré Superstructures
- Graduate Student Researcher: Devika Mehta
Sponsor: Office of Naval Research
Period: 06/2022-05/2023 - Materials with Extreme Phononic Coupling
- Graduate Student Researchers: Hwijong Lee, Chuting Cai
Collaboration: Profs. Feliciano Giustino, Jianshi Zhou - Sponsor: NSF MRSEC Center for Dynamics and Control of Materials
Period: 09/2021-08/2023 - Extraordinary Electronic Switching of Thermal Transport
- Graduate Student Researchers: Devika Mehta, Emma Peavler, Chuting Cai, Yajie Huang
Collaboration: Profs. Joshua Goldberger, Joseph Heremans, David Johnson, Phillip Kim, Allan MacDonald, Arun Majumdar
Sponsor: Office of Naval Research MURI
Period: 06/2021-06/2027
Thermalization of Microwave Components for Improved Qubit Coherence
- Nanofabrication, Modeling, and Characterization of Nano-mechanical/phononic/photonic Devices
- Post-doctoral Researcher: Dr. Brandon Smith
Collaboration: Dr. Matt Eichenfield
Sponsor: Sandia National Laboratories
Period: 11/2020-06/2021
- High-Order Phonon Scattering and Highly Nonequilibrium Carrier Transport in Two-dimensional Electronic and Optoelectronic Materials
- Graduate and Undergraduate Student Researchers: Peter Sokalski, Rodolfo Cantu
Collaboration: Prof. Xiulin Ruan (Purdue University)
Sponsor: National Science Foundation
Period: 07/2020-09/2023
- Collective Energy Transport of Excitons in Two-dimensional Materials
- Graduate Student Researcher: Yajie Huang
Collaboration: Prof. Steve Cronin (USC)
Sponsor: Department of Energy Office of Science
Period: 06/2019-05/2022
- Magnetism and Spin/Heat Coupling in Moiré Superstructures
- Post-doctoral & Graduate Student Researchers: Devika Mehta, Dr. Sean Sullivan, Dr. Xi Chen
Collaboration: Profs. Allan MacDonald, Emanuel Tutuc, Roberto Meyers, Joseph Heremans
Sponsor: Army Research Office
Period: 09/2018-09/2019
- Hydrodynamic Thermal Transport in Graphitic Materials
- Graduate Student Researchers: Eric Ou, Sean Sullivan, Jihoon Jeong
Collaboration: Prof. Yaguo Wang, Prof. Sangyeop Lee (University of Pittsburgh)
Sponsor: National Science Foundation
Period: 08/2017-07/2020 - Graduate Student Researchers: Evan Fleming, Sally Jia
Collaboration: Prof. Donglei Fan
Sponsor: National Science Foundation
Period: 09/2016-08/2019
- Energy Carrier Transport in Functionalized Two-Dimensional Layered Chalcogenides
- Graduate Student and Post-doctoral Researchers: Hwijong Lee, Dr. Mir Mohammad Sadeghi
Collaboration: Prof. Steve Cronin (USC)
Sponsor: Department of Energy Office of Science
Period: 06/2016-05/2019
- Ultrahigh Thermal Conductivity Materials
- Graduate Student and Post-doctoral Researchers: Yuanyuan Zhou, Hwijong Lee, Dr. Jaehyun Kim, Dr. Xi Chen, Dr. Sean Sullivan
Collaboration: Profs. David Broido (Boston College), David Cahill & Pinshane Huang (UIUC), Gang Chen (MIT), Ni Ni (UCLA), Zhifeng Ren (University of Houston), Bing Lv (University of Texas at Dallas), Jianshi Zhou (UT Austin)
Sponsor: Office of Naval Research MURI Program
Period: 06/2016-10/2021
- Graphitic Coatings and Porous Networks for Vehicle Thermal Management
- Graduate Student and Post-doctoral Researchers: Evan Fleming, Dr. Iskandar Kholmanov
Sponsor: Toyota Motor Corporation
Period: 04/2016-03/2017
- Probing Thermal Transport in Three-Dimensional Pillared Graphene Structures
- Graduate Student and Post-doctoral Researchers: Evan Fleming, Dr. Iskandar Kholmanov
Collaboration: Profs. Liming Dai (CWRU), Dr. Xiulin Ruan (Purdue), Dr. Ajit Roy (ARFL)
Sponsor: Airforce Office of Scientific Research MURI/Case Western Reserve University
Period: 09/2015-11/2017
- EFRI 2-DARE: Enhancing Electronic and Thermal Properties in Epitopotaxial Ge/Sn Graphane Heterostructures
- Graduate Student Researcher: Gabriella Coloyan, Devika Mehta
Collaboration: Profs. Joshua Goldberger (OSU), David Broido (Boston College), David Cahill (UIUC), Joseph Heremans (OSU)
Sponsor: National Science Foundation
Period: 09/2014-03/2020
- Development of Light Scattering Characterization Equipment for the Study of Magnon and Phonon Dynamics in Materials with Spin/Heat Coupling
- Collaboration: Prof. Elaine Li (UT Austin)
Sponsor: Army Research Office Defense University Research Instrumentation Program (DURIP)
Period: 06/2014-06/2015
- Size-dependent Phonon Transport in Boron Arsenide with Potentially Record-high Thermal Conductivity
- Post-doctoral & Graduate Student Researchers: JaeHyun Kim, Dan Evans, Owen Williams, Dr. Dan Sellan
Collaboration: Prof. Alan Cowley (UT Austin)
Sponsor: Office of Naval Research
Period: 06/2014-09/2017 - Fully Integrated 2D Nanomaterials for High-Performance Flexible Nanoelectronics
- Graduate Student Researcher: Brandon Smith
Collaboration: Prof. Deji Akinwande (UT Austin)
Sponsor: Office of Naval Research
Period: 01/2014-12/2017 - Probing Highly Non-equilibrium Thermal Transport in Nanostructures and Devices
- Graduate Student Researchers: Kevin Olsson, Sean Sullivan, Annie Weathers
Collaboration: Prof. Elaine Li (UT Austin)
Sponsor: National Science Foundation
Period: 09/2013-08/2017 - Materials with Extraordinary Spin/Heat Coupling
- Post-doctoral & Graduate Student Researchers: Dr. Annie Weathers, Dr. Xi Chen, Sean Sullivan, Dr. Kyongmo An
Collaboration: Profs. Roberto Meyers, Joseph Heremans (Ohio State University), David Cahill (UIUC), David Awschalom (Univ of Chicago), Yaroslav Tserkovnyak (UCLA), Elaine Li (UT Austin), Jianshi Zhou (UT Austin) Sponsor: Army Research Office Multidisciplinary Uiversity Research Intitiative (MURI)
Period: 12/2013-09/2019 - Phonon and Electron Transport in Pristine Two-Dimensional Layered Nanostructures and Heterostructures
- Graduate Student Researchers: Gabriella Coloyan, Eric Ou
Collaboration: Prof. Steve Cronin (USC)
Sponsor: Department of Energy Office of Basic Energy Science
Period: 06/2013-05/2016 - NSF Nanosystems Engineering Research Center: Nanomanufacturing Systems for Mobile Computing and Devices (NASCENT)
- Graduate Student Researchers: Qianyu (Sally) Jia, Brandon Smith, Gabriella Coloyan, David Choi, Mir Mohammad Sadeghi
Collaboration: Profs. Deji Akinwande, Jayathi Murthy
Sponsor: National Science Foundation
Period: 09/2012-08/2020 - MRI: Acquisition of a Spark Plasma Sintering System for Engineering Advanced Energy Materials and Materials Science Education
- Collaboration: Profs. Jianshi Zhou, John Goodenough, Arumugam Manthiram, Desiderio Kovar (UT Austin)
Sponsor: National Science Foundation
Period: 09/2012-06/2015 - Thermal Batteries for Electric Vehicles
- Post-doctoral & Graduate Student Researchers: Evan Fleming, Dr. Hengxing Ji, Dr. Abhijit Paul, Dr. Daniel Sellan, Dr. Shaoyi Wen, Dr. Eunsu Paek, Dr. Iskandar Kholmanov
Collaboration: Profs. Chris Bielawski, Alex da Silva, Rodney S. Ruoff, Jayathi Murthy, Gyeong Hwang, Dr. Peng Zhou, Dr. Dolf van der Heide
Sponsor: Department of Energy ARPA-E
Period: 11/2011-6/2015 - Topological Insulator Coherent Energy Devices
- Post-doctoral and Graduate Student Researchers: Dr. Michael Pettes, JaeHyun Kim
Sponsor: Defense Advanced Research Project Agency (DARPA) / Purdue University
Period: 06/2011-06/2015 - High-Performance Thermoelectric Devices based on Abundant Silicide Materials for Vehicle Waste Heat Recovery
- Graduate Student Researchers: Chad Baker, Xi Chen, Haiyan Fateh, Daniel Salta, Libin Zhang
Collaboration: Profs. J. B. Goodenough, M. J. Hall, J. S. Zhou (UT Austin), J. Song (University of Wisconsin-Madison)
Sponsor: National Science Foundation & Department of Energy Joint Thermoelectric Partnership
Period: 10/2010-05/2015 - Energy Transport in Graphene
- Graduate Student Researchers: Michael T. Pettes, Insun Jo, Mir Mohammad Sadeghi, Gabbi Coloyan
Collaboration: Prof. Steve Cronin (USC)
Sponsor: Department of Energy Office of Basic Energy Science
Period: 06/2010-05/2013 - Ballistic and Quantum Thermal Transport Phenomena and Devices
- Postdoctoral and Graduate Researchers: Dr. Jae Hun Seol, Dr. Arden Moore, JaeHyun Kim, Eric Ou
Sponsor: Office of Naval Research
Period: 02/2010-01/2013 - High-Throughput Nanoimprint Fabrication of Shape-Specific, Stimuli-responsive Polymeric Nanocarriers for Drug and Imaging Agent Delivery
- Graduate Student Researchers: Mary C. Moore, Vikramajit Singh, Patrick Jurney, Rachit Agarwal, Scott Marshall, David Choi
Collaboration: Prof. S.V. Sreenivasan (UT Austin), Prof. K. Roy (UT Austin), Dr. D. LaBrake (Molecular Imprint, Inc)
Sponsors: National Science Foundation
Period: 07/2009-09/2013 - Electronic Thermal Transport in Nanoscale Conductors
- Graduate Student Researchers: Mir Mohammad Sadeghi, Jae Hun Seol, Annie Weathers
Sponsor: National Science Foundation
Period: 07/2009-06/2013 - Characterization of Nanostructured Thermoelectric Materials
- Post-doctoral & Graduate Researchers: Dr. Arden Moore, Dr. Huijun Kong, Dr. Yong Lee, Dr. Michael Pettes, JaeHyun Kim
Sponsor: Office of Naval Research
Period: 07/2008-09/2011 - Shape Specific, Enzyme-Responsive, Nano-Imprinted Particles for Drug Delivery
- Graduate Student Researchers: Mary C. Moore, Rachit Agarwal, JaeHyun Kim
Collaboration: Prof. K. Roy (UT Austin)
Sponsors: National Institute of Health
Period: 07/2008-06/2011 - Batch-Fabricated Nanowire Plasmonic Probes for Near Field Imaging of Single Molecules and Cells
- Graduate Student Researcher: JaeHyun Kim
Post-doctoral Researcher: Dr. Yong Lee
Sponsor: Texas Higher Education Coordinating Board Norman Hackerman Advanced Research Program
Period: 05/2008-05/2010 - Structure-Optical-Thermal Relationships of Carbon Nanotubes
- Graduate Student Researchers: Michael T. Pettes, JaeHyun Kim
Collaboration: Prof. Steve Cronin (USC)
Sponsor: Department of Energy Office of Basic Energy Science
Period: 06/2007-05/2010 - Catalyst Substrates with Nanoscale Features for Enhanced Reaction Activity
- Graduate Student Researcher: Chad Baker
Collaboration: Prof. M. J. Hall (UT Austin)
Sponsor: Texas Hazardous Waste Research Center
Period: 09/2007-08/2010 - High Temperature and Magnet Cryostats for Characterization of Nanowire and Thin Film Thermoelectric Materials
- Sponsor: Office of Naval Research
Period: 05/2007-09/2008 - Thermal Transport at Nanoscale Point and Line Constrictions and Interfaces
- Graduate Student Researchers: Jae Hun Seol, Arden L. Moore, Nathan Malcolm, Sanjoy Saha
Collaboration: Prof. John R. Howell (UT Austin), Dr. Ravi S. Prasher (Intel)
Sponsor: National Science Foundation
Period: 09/2006-08/2010 - NER: Nanoimprint Fabrication of Stimuli-responsive Drug Delivery Carriers
- Graduate Student Researchers: Luz Cristal Glanchai, Mary C. Moore
Collaboration: Prof. K. Roy (UT Austin)
Sponsors: National Science Foundation
Period: 08/2006-07/2007 - Room-Temperature Scanning Single-Electron-Transistor Microscopy of Nanoelectronic Devices
- Gradate Student Researcher: Michael T. Pettes
Post-doctoral Researcher: Dr. Yong Lee
Collaboration: Prof. Zhen Yao (UT Austin)
Sponsor: Texas Higher Education Coordinating Board Norman Hackerman Advanced Research Program
Period: 08/2006-07/2008 - Nanowire Composite Peltier Coolers
- Graduate Student Researcher: Arden L. Moore
Sponsor: DARPA Advanced Processing and Prototyping Center (AP2C)
Period: 11/2005-11/2006 - Investigation of Electrical Conductivity of Silicide and Copper Nanowires
- Gradate Student Researcher: Bin Li
Collaboration: Prof. Paul S. Ho (UT Austin)
Sponsor: National Institute of Standards & Technology
Period: 06/2005-05/2006 - Nanowire Composites for Energy Efficient Thermoelectric Refrigeration and Power Generation in Space Applications
- Graduate Student Researchers: Feng Zhou, Jae Hun Seol
Collaborations: Dr. Laura Ye, Dr. Natalio Mingo, NASA Ames Research Center
Sponsor: NASA through Eloret Corporation
Period: 05/2005-05/2007 - Directed Assembly of Metal Oxide Nanowires with Microsystems for Sensor Applications
- Graduate Student Researcher: Choongho Yu
Collaboration: Prof. Z. L. Wang (Georgia Institute of Technology)
Sponsor: UT Research Grant Program - Period: 09/2004-08/2005
- Novel Nano and Micro-fabrication Methods for Injectable, Tissue-targeted, Stimuli-responsive Delivery Vehicles: Towards Simultaneous Delivery of Therapeutics and Contrast-agents
- Graduate Student Researchers: Luz Cristal Glanchai, Mary C. Moore
Collaboration: Prof. K. Roy (UT Austin)
Sponsors: Charles W. Tate & Judy Spence Tate Charitable Foundation through UT Center for Biomedical Engineering
Period: 09/2004-08/2005 - Nanoconductors for Future Interconnects and Air Bridge Interconnects
- Graduate Student Researcher: Bin Li, Anastassios Mavrokefalos
Collaboration: Prof. Paul S. Ho, Zhen Yao, Rui Huang (UT Austin)
Sponsor: SEMATECH
Period: 09/2004-08/2006 - YIP: Characterization of Nanostructures for Efficient Thermoelectric Refrigeration and Power Generation
- Graduate Student Researchers: Anastassios Mavrokefalos, Feng Zhou
Sponsor: Office of Naval Research
Period: 06/2004-09/2008 - Compact General-Purpose Bioagent Detector
- Collaboration: Prof. Peter Gascoyne (UT MD Anderson Cancer Center), Prof. Shaochen Chen (UT Austin)
Sponsor: DOD Space and Naval Warfare Center
Period: 07/2003-06/2004 - CAREER: Thermal Transport and Thermoelectric Measurements of Nanotransistors, Nanowires, and Superlattices
- Graduate Student Researchers: Choongho Yu, Jianhua Zhou, Sanjoy Saha, Michael T. Pettes, Jae Hun Seol
Sponsor: National Science Foundation
Period: 03/2003-02/2008 - Micro-flow Cytometers based on Dielectrophoretic Particle Focusing
- Graduate Student Researcher: Choongho Yu
Collaboration: Prof. Peter Gascoyne (UT MD Anderson Cancer Center)
Sponsor: Whitaker Foundation through UT Center for Biomedical Engineering
Period: 09/2002-06/2003 - Acquisition of a Scanning Probe Microscope and a Liquid Helium Cryostat for Nanoscale Thermal Science Research and Education at the University of Texas at Austin
- Collaboration: Profs. Shaochen Chen and Zhen Yao (UT Austin)
Sponsor: National Science Foundation
Period: 06/2002-07/2004
