Article
Nanoscience & Nanotechnology
Yiwen Song, Praneeth Ranga, Yingying Zhang, Zixuan Feng, Hsien-Lien Huang, Marco D. Santia, Stefan C. Badescu, C. Ulises Gonzalez-Valle, Carlos Perez, Kevin Fern, Robert M. Lavelle, David W. Snyder, Brianna A. Klein, Julia Deitz, Albert G. Baca, Jon-Paul Maria, Bladimir Ramos-Alvarado, Jinwoo Hwang, Hongping Zhao, Xiaojia Wang, Sriram Krishnamoorthy, Brian M. Foley, Sukwon Choi
Summary: This study investigates the thermal conductivity of heteroepitaxial beta-Ga2O3 films, and finds that the thermal conductivity is strongly influenced by film thickness, crystallinity, and substrate offcut angles. Additionally, the thermal conductivity of ((2) over bar 01)-oriented beta-(AlxGal)(2)O-3 thin films grown via MOVPE was characterized, with results showing lower conductivity due to phonon-alloy disorder scattering. These findings provide fundamental insights for the development of beta-Ga2O3 electronic and optoelectronic devices.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Nanoscience & Nanotechnology
Weidong Zheng, Connor J. McClellan, Eric Pop, Yee Kan Koh
Summary: In this study, accurate measurements of thermal boundary resistance (R) of 2D material interfaces were conducted. It was found that, in addition to phonon transport, thermal resistance between nonequilibrium phonons in the 2D materials could also play a critical role. These findings provide important insights into heat dissipation in 2D material devices and highlight the significance of considering the influence of nonequilibrium phonons in device design.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Crystallography
Jian-Sian Li, Hsiao-Hsuan Wan, Chao-Ching Chiang, Xinyi Xia, Timothy Jinsoo Yoo, Honggyu Kim, Fan Ren, Stephen J. Pearton
Summary: Vertical heterojunction rectifiers with p-type NiO and thick Ga2O3 drift layers grown on Sn-doped β-Ga2O3 substrates exhibited breakdown voltages > 8 kV. Low drift doping concentration, low power during NiO deposition, and the formation of a guard ring were key factors for achieving excellent performance. These results demonstrate the potential of NiO/Ga2O3 rectifiers beyond SiC and GaN.
Article
Nanoscience & Nanotechnology
Zhe Cheng, Fengwen Mu, Xiaoyang Ji, Tiangui You, Wenhui Xu, Tadatomo Suga, Xin Ou, David G. Cahill, Samuel Graham
Summary: This work introduces a thermal mapping technique for buried semiconductor interfaces and identifies weakly bonded interfaces caused by high-temperature annealing. It also highlights the capability of using steady-state temperature rise induced by TDTR laser to probe thermal boundary conductance variations of buried interfaces.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Engineering, Electrical & Electronic
Samantha Jones-Jackson, Romina Rodriguez, Yuhang Yang, Luis Lopera, Ali Emadi
Summary: The design of thermal management solutions has a significant impact on the reliability and power density of power electronics in electric vehicles (EVs). This article reviews the thermal management strategies and failure modes of major power electronic components in EVs, as well as current cooling designs and future cooling trends for the next generation of power electronics.
IEEE TRANSACTIONS ON TRANSPORTATION ELECTRIFICATION
(2022)
Article
Engineering, Electrical & Electronic
Florian Wilhelmi, Yuji Komatsu, Shinya Yamaguchi, Yuki Uchida, Tadashi Kase, Shinji Kunori, Andreas Lindemann
Summary: This article evaluates different assembly strategies for Gallium oxide (Ga2O3) Schottky diodes and discusses the influence of substrate thickness, on-resistance, and assembly method on the power and current rating of the diodes. It also shows that optimizing the die attach thickness or using underfill materials in a specific configuration can reduce the average junction temperature and local temperature peaks.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2023)
Article
Thermodynamics
Jason Velardo, Randeep Singh, Phan Thanh Long, Mladenko Kajtaz, Abhijit Date
Summary: In this study, a method for predicting the thermal resistance of a vapour chamber was developed and integrated into a thermal management system model. The model showed good agreement with experimental results and revealed that the vapour chamber accounted for 40% of the total thermal resistance. The spreading sub-model was found to have the largest contribution to the thermal resistance of the vapour chamber.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Review
Chemistry, Multidisciplinary
Wenkui Xing, Yue Xu, Chengyi Song, Tao Deng
Summary: With the advancement of modern electronics, there is a growing need for efficient heat dissipation in high-power electronic systems. This article introduces advanced thermal interface materials (TIMs) with high thermal conductivity and low interfacial thermal resistance, and discusses their heat dissipation models, classification, performances, fabrication methods, recent research status, and developing trends in the micro- and nanoscale TIMs for high-power electronics.
Review
Physics, Applied
Yuan Qin, Zhengpeng Wang, Kohei Sasaki, Jiandong Ye, Yuhao Zhang
Summary: Benefitted from progress on the large-diameter Ga2O3 wafers and processing techniques, Ga2O3 power device technology has rapidly advanced for power electronics applications. Reports on large-area Ga2O3 power devices have emerged globally, going beyond device demonstration to packaging, testing, and evaluation. Ga2O3 is the only wide bandgap semiconductor reaching these milestones for power device development. This paper provides a timely review on ampere-class Ga2O3 power devices, covering their electrical performance, switching characteristics, packaging and thermal management, and ruggedness and reliability.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Jingjing Shi, Chao Yuan, Hsien-Lien Huang, Jared Johnson, Chris Chae, Shangkun Wang, Riley Hanus, Samuel Kim, Zhe Cheng, Jinwoo Hwang, Samuel Graham
Summary: This study investigates thermal transport at beta-Ga2O3/metal interfaces using theoretical modeling and experimental measurements. It highlights the significant impact of metal cutoff frequency on thermal boundary conductance, followed by chemical reactions and defects. Different metals show varying effects on the thermal boundary conductance in these interfaces.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Physics, Applied
Robert H. Montgomery, Yuewei Zhang, Chao Yuan, Samuel Kim, Jingjing Shi, Takeki Itoh, Akhil Mauze, Satish Kumar, James Speck, Samuel Graham
Summary: By using a thermally conductive dielectric over the MOSFET structure and bonding thermal spreaders to its topside, significant improvements in device power density and thermal performance can be achieved.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Thermodynamics
Li Zhang, Huayong Zhao, Shuibao Liang, Changqing Liu
Summary: An integrated batteries and power electronics system has the potential to improve the compactness, flexibility, and multifunctionality of electrical vehicles. However, it faces challenges in thermal management due to the different operating temperatures of batteries and power electronics. This paper presents a systematic study on the heat transfer characteristics in a phase change materials (PCMs) based thermal management system, using a validated three-dimensional heat transfer model. The key parameters affecting the system are identified, and it is found that increasing kxy and reducing Ja are beneficial for system operation duration, while increasing kz has an optimal value.
APPLIED THERMAL ENGINEERING
(2023)
Article
Materials Science, Multidisciplinary
Dmitrii A. Bauman, Dmitrii Iu Panov, Dmitrii A. Zakgeim, Vladislav A. Spiridonov, Arina Kremleva, Artem A. Petrenko, Pavel N. Brunkov, Nikita D. Prasolov, Alexey Nashchekin, Andrei M. Smirnov, Maxim A. Odnoblyudov, Vladislav E. Bougrov, Alexey E. Romanov
Summary: A method for growing high-quality gallium oxide bulk crystals from the melt was developed, with a focus on studying the influence of the atmosphere on growth stability and crystal quality. The structural properties of the obtained crystals were investigated, and the potential for growing bulk crystals of solid-solution oxides was explored.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Shaodong Zhang, Shuangru Li, Lei Wei, Huadi Zhang, Xuping Wang, Bing Liu, Yuanyuan Zhang, Rui Zhang, Chengcheng Qiu
Summary: Ferroelectric domain walls of perovskite oxide materials, such as KTa1-xNbxO3, can be manipulated by an external electric field and have potential applications in thermal switching. In this study, the thermal conductivity and thermal boundary resistance of KTN domain walls were investigated using nonequilibrium molecular dynamics simulations. The results showed that the thermal conductivity decreased with the number of domain walls, indicating the excellent performance of the thermal switch. The thermal boundary resistance of a single KTN domain wall was also evaluated, and a large thermal switch ratio was observed. This study demonstrates the potential of ferroelectric KTN for thermal switch applications at room temperature and over a broad temperature range.
Article
Physics, Multidisciplinary
Bin Wei, Qingan Cai, Qiyang Sun, Yaokun Su, Ayman H. Said, Douglas L. Abernathy, Jiawang Hong, Chen Li
Summary: By measuring the Matryoshka phonon dispersions, insights into the anisotropic thermal conductivity of semiconducting alpha-GaN have been gained, showing how phonon topology affects thermal transport in the material. This study demonstrates the importance of understanding lattice dynamics for effective thermal management in electronic devices.
COMMUNICATIONS PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Ashutosh Giri, Austin M. Evans, Muhammad Akif Rahman, Alan J. H. McGaughey, Patrick E. Hopkins
Summary: This article demonstrates that stacks of two-dimensional covalent organic frameworks possess unique physical properties, including low densities, high thermal conductivities, and highly negative Poisson's ratios. These properties arise from their singular layered architecture and structural modularity.
Article
Chemistry, Multidisciplinary
Mallory E. DeCoster, Hasan Babaei, Sangeun S. Jung, Zeinab M. Hassan, John T. Gaskins, Ashutosh Giri, Emma M. Tiernan, John A. Tomko, Helmut Baumgart, Pamela M. Norris, Alan J. H. McGaughey, Christopher E. Wilmer, Engelbert Redel, Gaurav Giri, Patrick E. Hopkins
Summary: In this study, we experimentally and theoretically investigate the effects of guest molecules on the thermal conductivity and mechanical properties of porous crystals. The results show that the infiltration of guest molecules reduces the thermal conductivity and increases the density and heat capacity. Atomistic simulations reveal that the reduction in thermal conductivity is attributed to increased vibrational scattering and modifications to the intrinsic vibrational structure of the crystal induced by the guest molecules.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Instruments & Instrumentation
Xiaoman Wang, Minyoung Jeong, Alan J. H. McGaughey, Jonathan A. Malen
Summary: This study proposes a method to reduce the uncertainty in thermal property measurements due to the uncertainty in the laser spot radius in frequency-domain thermoreflectance experiments. The effectiveness of the method is validated through numerical and real experiments. The method has shown to significantly decrease the overall uncertainty in thermal conductivity measurements, especially when the spot radius is well known.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2022)
Article
Construction & Building Technology
Noreen Saeed, Jonathan A. Malen, Maysamreza Chamanzar, Ramesh Krishnamurti
Summary: The paper proposes a method to predict thermal conductivity of building envelopes using dielectric properties and confirms a strong correlation between thermal conductivity and relative dielectric constant of wood and wood-based materials.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
Shuyan Zhang, Jie Gong, Daniel Z. Xiao, B. Reeja Jayan, Alan J. H. McGaughey
Summary: A workflow is presented for performing pair distribution function (PDF) analysis of defected materials using structures generated from atomistic simulations. The workflow involves obtaining a large collection of structures with different types and concentrations of defects through energy minimization and refining them against an experimental PDF. The workflow is applied to a-TiO2 and t-ZrO2 synthesized in the presence of microwave radiation, revealing the dominant defects in each material.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Chemistry, Physical
Meiirbek Islamov, Hasan Babaei, Ryther Anderson, Kutay B. Sezginel, Jeffrey R. Long, Alan J. H. McGaughey, Diego A. Gomez-Gualdron, Christopher E. Wilmer
Summary: Thermal energy management in metal-organic frameworks (MOFs) is a challenge that is often overlooked but important for adsorption-based applications such as gas storage and separations. This study uses large-scale computational screening to investigate the structure-property relationships governing thermal transport in MOFs. The findings suggest that high thermal conductivity in MOFs is favored by high densities, small pores, and four-connected metal nodes.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Laura A. Cramer, Amanda Larson, Avery S. Daniels, E. Charles H. Sykes, Andrew J. Gellman
Summary: Recent experiments have shown that the adsorption of a nonracemic mixture of aspartic acid (Asp) enantiomers on a nonchiral Cu(111) metal surface can amplify the surface enantiomeric excess (ees) to values higher than the concentration of the incoming gas mixtures (eeg). This indicates that a slightly nonracemic mixture of enantiomers can be purified by simply being adsorbed onto a nonchiral surface. In this study, scanning tunneling microscopy was used to investigate the structures formed by mixed monolayers of D- and L-Asp on Cu(111) with varying ees values. The results showed the presence of three chiral monolayer structures, including a conglomerate, a racemate, and a phase accommodating both enantiomers at a 2:1 ratio.
Article
Chemistry, Physical
Jonathan J. Wang, Jie Gong, Alan J. H. Mcgaughey, Dvira Segal
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Nicholas Golio, Andrew J. Gellman
Summary: By using a composition spread alloy film, the catalytic activity of AgPd catalysts for ethylene hydrogenation was studied. It was found that adding a moderate amount of oxygen can significantly enhance the performance of the catalyst, and this enhancement strongly depends on the catalyst composition and reaction conditions.
Article
Chemistry, Multidisciplinary
Laisuo Su, Shuyan Zhang, Alan J. H. McGaughey, B. Reeja-Jayan, Arumugam Manthiram
Summary: A method to predict the entire charge curve of a battery with limited input information is developed, achieving an error of less than 2% using only 10% of the charge curve as input.
Review
Chemistry, Multidisciplinary
Camille Ferris, Nicholas Golio, Herve Martinez, Andrew J. Gellman
Summary: In this article, we emphasize the importance and capabilities of composition spread alloy films (CSAFs) for the high-throughput study and comprehensive understanding of corrosion passivation in multicomponent alloys. By addressing the mechanistic issues associated with corrosion and the problems arising from the corrosion of metals, we establish the need for further studying and understanding the mechanisms of alloy corrosion and corrosion passivation. We highlight the development of new combinatorial methods that overcome the experimental bottleneck and illustrate the use of CSAFs in studying corrosion across alloy composition space.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Meiirbek Islamov, Paul Boone, Hasan Babaei, Alan J. H. McGaughey, Christopher E. Wilmer
Summary: Thermal transport in metal-organic frameworks (MOFs) is essential but often overlooked. This study investigates the influence of defects on the thermal conductivity of the MOF UiO-66 and finds that the spatial arrangement of defects significantly affects thermal conductivity, with the spatially correlated missing linker defect nanodomain (bcu topology) displaying intriguing anisotropy, with higher thermal conductivity along a particular direction compared to the defect-free UiO-66.
Article
Physics, Applied
Henry T. Aller, Alan J. H. McGaughey, Jonathan A. Malen
Summary: Rapid thermal annealing significantly improves the thermal conductivity of amorphous alumina thin films and reduces the thermal boundary resistance of adjacent interfaces, which promotes heat spreading and enhances device longevity.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Yilin Yang, Zhitao Guo, Andrew J. Gellman, John R. Kitchin
Summary: Simulation of the segregation profile of multi-component alloys is important for investigating the catalytic properties of alloy catalysts. In this study, a neural network-based surrogate model was used to evaluate the potential energies of a ternary Cu-Pd-Au alloy, and the segregation profile was obtained using Monte Carlo simulation. The results were compared with experimental data, revealing discrepancies in certain cases.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Materials Science, Multidisciplinary
Carlos Fernandez-Caban, Burcu Karagoz, Petro Kondratyuk, Andrew J. Gellman
Summary: By conducting a comprehensive mapping of enantiospecific surface reactivity on Cu(hkl) surfaces vicinal to Cu(111), the study reveals the importance of chirality in surface reactions and measures the reaction kinetics constants for different surfaces.
MATERIALS ADVANCES
(2022)
