Article
Chemistry, Multidisciplinary
Yunkyu Park, Hyeji Sim, Kyung-Yeon Doh, Minguk Jo, Donghwa Lee, Si -Young Choi, Junwoo Son
Summary: This study demonstrates the importance of electron supply in controlling charged ionic flow and proposes a strategy for ion-defect-induced emergent properties at interfaces.
Article
Multidisciplinary Sciences
Qinshu Li, Fang Liu, Song Hu, Houfu Song, Susu Yang, Hailing Jiang, Tao Wang, Yee Kan Koh, Changying Zhao, Feiyu Kang, Junqiao Wu, Xiaokun Gu, Bo Sun, Xinqiang Wang
Summary: This study reveals that even for materials with similar Debye temperatures, a significant portion of phonons can transport inelastically across interfaces at high temperatures, greatly enhancing the interface thermal conductance. The sharpness of the interface strongly affects the phonon transport process. These findings provide new insights and opportunities for engineering interface thermal conductance in microelectronics materials.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Jingjing Wang, Ziyang Wang, Kunming Yang, Naiqi Chen, Jiamiao Ni, Jian Song, Quan Li, Fangyuan Sun, Yue Liu, Tongxiang Fan
Summary: Interfacial thermal resistance plays a critical role in heat dissipation. This study investigates the influence of interface defects on phonon scattering and finds that inelastic phonon scattering may greatly promote interfacial heat transport. The findings provide insights into nanoscale heat transport mechanisms at metal/nonmetal interfaces.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
N. D. Le, B. Davier, N. Izitounene, P. Dollfus, J. Saint-Martin
Summary: A Full Band Monte Carlo simulator has been developed to study phonon transmission across interfaces and determine thermal conductivity at thermal interfaces. This simulator can consider all phonon transport regimes and provides new insights into out-of-equilibrium phonon transport near the interfaces.
JOURNAL OF COMPUTATIONAL ELECTRONICS
(2022)
Article
Chemistry, Multidisciplinary
Natalya S. Fedorova, Andrea Cepellotti, Boris Kozinsky
Summary: This study uncovers a new phenomenon where the electrical conductivity decreases with carrier concentration, the Seebeck coefficient reverses sign even at high doping, and the power factor exhibits an unusual second peak in materials with multiple bands crossing near the Fermi level. The origin and magnitude of this effect are explained, and general design rules for enhancing performance in thermoelectric materials are identified.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Review
Chemistry, Multidisciplinary
Ashutosh Giri, Scott G. Walton, John Tomko, Niraj Bhatt, Michael J. Johnson, David R. Boris, Guanyu Lu, Joshua D. Caldwell, Oleg V. Prezhdo, Patrick E. Hopkins
Summary: The coupled interactions among charge, heat, and electromagnetic fields at interfaces and boundaries enable various technologies. Thermal dissipation at these surfaces drives the functionalities of nanotechnologies in computing, communication, healthcare, clean energy, power recycling, sensing, and manufacturing. This review summarizes recent works on ultrafast and nanoscale energy transduction and heat transfer mechanisms across interfaces when different thermal carriers couple near or across interfaces.
Article
Physics, Multidisciplinary
Antonios M. Alvertis, Jonah B. Haber, Edgar A. Engel, Sahar Sharifzadeh, Jeffrey B. Neaton
Summary: In this study, a first-principles investigation was conducted on solid pentacene using density functional theory, the ab initio GW-Bethe-Salpeter equation approach, finite-difference, and path integral techniques. The research captured the formation of bound excitons, exciton-phonon coupling to all orders, and phonon anharmonicity. It was found that the zero-point nuclear motion of pentacene leads to uniformly strong localization, with additional localization provided by thermal motion only for Wannier-Mott-like excitons. Anharmonic effects drive temperature-dependent localization, and conditions under which highly delocalized excitons might emerge were explored.
PHYSICAL REVIEW LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Wenjie Hao, Minghui Gu, Zhenyun Tian, Shaohua Fu, Meng Meng, Hong Zhang, Jiandong Guo, Jimin Zhao
Summary: By employing ultrafast spectroscopy, this study uncovers the spatial separation between electron-phonon coupling (EPC) and phonon-phonon scattering (PPS), providing a vital foundation for designing future quantum nano devices.
Review
Materials Science, Multidisciplinary
Nagaraj Nandihalli
Summary: The significance of interfaces and grain boundaries in contemporary thermoelectric literature is highlighted. Understanding the relationship between grain boundaries/interphase boundaries and property connections is crucial for material design. Microstructure control and interface manipulation have become critical topics in the field of thermoelectrics. This paper discusses recent breakthroughs in high-performance TE material design, focusing on strategies for thermal conductivity reduction and electron and phonon transport decoupling. It also reviews the TE properties of various materials prepared using these strategies.
CRITICAL REVIEWS IN SOLID STATE AND MATERIALS SCIENCES
(2023)
Article
Physics, Applied
Mamta Raturi, Anirban Kundu, Renu Rani, Jyoti Saini, Kiran S. Hazra
Summary: The study demonstrates a non-contact and direct method to accurately probe the energy band bending on MoS2 flakes by mapping the surface potential landscape during carrier injection under non-equilibrium conditions. Experimental determination of corresponding interfacial parameters provides important information for controlling charge carrier diffusion in semiconducting channels.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Physical
Mikhail Pylnev, Tzu-Sen Su, Tzu-Chien Wei
Summary: A novel low-temperature augmentation method using aqueous TiI4 solution was introduced for TiO2 in perovskite solar cells, resulting in higher efficiency and reproducibility. Covering the TiO2 surface with iodide ions tunes its work function and conduction band, increasing the open-circuit voltage of the photovoltaic device.
APPLIED SURFACE SCIENCE
(2021)
Review
Chemistry, Multidisciplinary
Deying Luo, Xiaoyue Li, Antoine Dumont, Hongyu Yu, Zheng-Hong Lu
Summary: The focus of the research is on discussing surface and interface engineering to reduce deep-level defects, and by selecting appropriate materials and processing methods to enhance the device performance of both solar cells and light-emitting diodes.
ADVANCED MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Tim Bernges, Martin Peterlechner, Gerhard Wilde, Matthias T. Agne, Wolfgang G. Zeier
Summary: The reduction of vibrational contributions to thermal transport and the search for materials with low lattice thermal conductivities are crucial in thermoelectric research. Spectral analytical models have been proven effective in understanding the physics of low thermal conduction, but another mechanism called diffusons has been discovered in complex crystalline materials. This work proposes an analytical 2-channel transport model that explains the thermal conductivities of the solid solution series Ag9-xGa1-xGexSe6 and provides materials design metrics for 2-channel thermal transport.
MATERIALS TODAY PHYSICS
(2023)
Article
Multidisciplinary Sciences
Zhe Cheng, Ruiyang Li, Xingxu Yan, Glenn Jernigan, Jingjing Shi, Michael E. Liao, Nicholas J. Hines, Chaitanya A. Gadre, Juan Carlos Idrobo, Eungkyu Lee, Karl D. Hobart, Mark S. Goorsky, Xiaoqing Pan, Tengfei Luo, Samuel Graham
Summary: Localized interfacial phonon modes have been observed at a high-quality epitaxial Si-Ge interface at around 12 THz, which significantly contribute to the total thermal boundary conductance. Through molecular dynamics simulations and experimental validation, the impact of these interfacial phonon modes on total thermal boundary conductance has been revealed.
NATURE COMMUNICATIONS
(2021)
Article
Thermodynamics
Wenlong Bao, Zhaoliang Wang, Dawei Tang
Summary: The study focused on investigating the interfacial thermal transport between GaN and AlN, revealing a higher thermal conductivity compared to other interfaces. Structural similarity and interfacial phonon modes were employed to uncover the heat transfer mechanism, along with calculations of temperature and wave-resolved spectral heat flux. This research contributes to an effective understanding and improvement of thermal management in GaN-based devices.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Physics, Applied
Ramin Ghiyasi, Milena Milich, John Tomko, Girish C. Tewari, Mika Lastusaari, Patrick E. Hopkins, Maarit Karppinen
Summary: ZnO thin films fabricated via atomic layer deposition process can simultaneously manipulate the electrical and thermal transport characteristics by elongating the N-2 purge time. This leads to increased carrier density and enhanced electrical conductivity, but may hinder thermal transport. This is of fundamental importance in thermoelectrics and desired in optics and microelectronics.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Applied
Kathleen Quiambao-Tomko, Richard R. White, John A. Tomko, Christina M. Rost, Lavina Backman, Elizabeth J. Opila, Patrick E. Hopkins
Summary: This work presents a laser-based heating and sensing metrology to study the failure mechanisms of materials under extreme heat fluxes near surfaces. By controlling the localization of heat fluxes through focusing the laser beam, the material damage can be evaluated using a secondary probe laser. The experiment focuses on the damage mechanisms of commercially pure titanium under high heat fluxes induced by absorbed laser energy. The study reveals correlations between microstructural evolution events and thermoreflectance trends as a function of absorbed power density.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Applied
Patrick E. Hopkins, John A. Tomko, Ashutosh Giri
Summary: In this study, a theoretical model for phonon thermal boundary conductance across solid interfaces in the high temperature classical limit is derived using quasi-harmonic thermodynamics. The model takes into account the effects of phonon anharmonicity on energy density changes and shows good agreement with experimental and simulation results. This model has the potential to be applied in various applications to increase thermal conductance and mitigate temperature.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Maria Gabriela Sales, Shelby Fields, Samantha Jaszewski, Sean Smith, Takanori Mimura, Wendy L. Sarney, Sina Najmaei, Jon F. Ihlefeld, Stephen McDonnell
Summary: Direct integration of transition metal dichalcogenides on a ferroelectric HZO substrate using molecular beam epitaxy (MBE) is investigated in this study. The results show that the crystallinity and composition of the HZO substrate can affect the degree of Se incorporation. However, measurements of the electrical properties of the HZO films did not show any negative impact of the incorporated Se on the functionality of the ferroelectric layer.
Article
Chemistry, Multidisciplinary
Carol F. Glover, Tsuyoshi Miyake, Victor Wallemacq, Jamie D. Harris, John Emery, Daniel A. Engel, Stephen J. McDonnell, John R. Scully
Summary: Contamination of high-touch surfaces with infected droplets of bodily secretions is a known route of virus transmission. Copper surfaces have the ability to inactivate human coronaviruses by releasing ions, making them a potential preventive strategy. This study investigated the virus inactivation effect on copper surfaces under realistic conditions and discovered that the half-life of the virus decreased five times compared to previous knowledge, indicating that virus inactivation on copper surfaces may be more effective than previously thought.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Eric R. R. Hoglund, De-Liang Bao, Andrew O'Hara, Thomas W. W. Pfeifer, Md Shafkat Bin Hoque, Sara Makarem, James M. M. Howe, Sokrates T. T. Pantelides, Patrick E. E. Hopkins, Jordan A. A. Hachtel
Summary: Grain boundaries are a common microstructural feature that greatly influence the functionality of various materials. Extensive experimental and theoretical studies have been conducted to understand the correlation between atomic-scale grain boundary structures and macroscopic properties. In this study, a SrTiO3 grain boundary was examined using advanced microscopy and spectroscopy techniques, along with density functional theory. The results provide insights into the impact of individual boundaries on macroscopic properties through the analysis of localized grain boundary vibrations.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Ashutosh Giri, Pravin Karna, Patrick E. Hopkins
Summary: This study demonstrates using density functional perturbation theory that aluminum exhibits the largest change in thermal conductivity under extreme pressures at room temperature compared to any other known material. This is attributed to the relatively larger increase in mean free paths and lifetimes of electrons in aluminum under higher pressures due to weaker electron-phonon coupling.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Pravin Karna, Md Shafkat Bin Hoque, Sandip Thakur, Patrick E. Hopkins, Ashutosh Giri
Summary: We demonstrate through experiments that the ballistic length of hot electrons in laser-heated gold films can exceed approximately 150 nm, which is around 50% longer than the previous value of 100 nm determined from pump-probe experiments. Additionally, we observe that the mean free path of electrons after interband excitation can reach upwards of around 45 nm, which is higher than the average value of 30 nm predicted by our parameter-free density functional perturbation theory. Our first-principles calculations on electron-phonon coupling elucidate that the increase in mean free path due to interband excitation is a result of reduced electron-phonon coupling from lattice stiffening, providing a microscopic understanding of our experimental findings.
Article
Nanoscience & Nanotechnology
Christina M. Rost, Daniel L. Schmuckler, Clifton Bumgardner, Md Shafkat Bin Hoque, David R. Diercks, John T. Gaskins, Jon-Paul Maria, Geoffrey L. Brennecka, Xiadong Li, Patrick E. Hopkins
Summary: This study investigates the property changes across the phase boundary between high-entropy and entropy-stabilized phases in ceramic materials. The thermal and mechanical properties of Mg0.2Co0.2Ni0.2Cu0.2Zn0.2O are studied using various methods. The results show that the thermal conductivity remains constant, while the linear coefficient of thermal expansion increases and mechanical softening is observed across the transition.
Article
Physics, Applied
Kenny Huynh, Yekan Wang, Michael E. Liao, Thomas Pfeifer, John Tomko, Ethan Scott, Khalid Hattar, Patrick E. Hopkins, Mark S. Goorsky
Summary: The recovery of silicon thermal conductivity was achieved through recrystallization of partially amorphized silicon. Transmission electron microscopy revealed nanoscale amorphous regions within a structurally distorted crystalline material. After annealing, strain recovery and recrystallization occurred, resulting in a bulk-like thermal conductivity in silicon.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Chemistry, Physical
Muhammad A. Rahman, Sandip Thakur, Patrick E. Hopkins, Ashutosh Giri
Summary: By using DFT calculations and MD simulations, the influence of molecular functional groups and porosities on the electronic and thermal properties of 2D COFs are studied. It is found that mass densities or network porosities are the main factors dictating the band gaps, and specific functional groups forming the nodes can lead to wider band gaps. In terms of thermal properties, mass density is also a main factor governing heat conduction, and increasing porosities result in reduced thermal conductivities. Therefore, the study provides insights into the fundamental changes in the microscopic thermodynamics of 2D COFs and offers a blueprint for the synthesis of 2D COFs with desired electronic and thermal properties.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Materials Science, Multidisciplinary
Cormac Toher, Mackenzie J. Ridley, Kathleen Q. Tomko, David Hans Olson, Stefano Curtarolo, Patrick E. Hopkins, Elizabeth J. Opila
Summary: Rare-earth silicates, used as environmental barrier coatings, show systematic trends in their properties. By combining first-principles calculations and experimental measurements, this study investigates the relationship between these properties and the radius of the rare-earth cation. The results provide design rules for developing new thermal and environmental barrier coatings with optimized functionality.
Review
Chemistry, Multidisciplinary
Ashutosh Giri, Scott G. Walton, John Tomko, Niraj Bhatt, Michael J. Johnson, David R. Boris, Guanyu Lu, Joshua D. Caldwell, Oleg V. Prezhdo, Patrick E. Hopkins
Summary: The coupled interactions among charge, heat, and electromagnetic fields at interfaces and boundaries enable various technologies. Thermal dissipation at these surfaces drives the functionalities of nanotechnologies in computing, communication, healthcare, clean energy, power recycling, sensing, and manufacturing. This review summarizes recent works on ultrafast and nanoscale energy transduction and heat transfer mechanisms across interfaces when different thermal carriers couple near or across interfaces.
Article
Materials Science, Multidisciplinary
Kiumars Aryana, Hyun Jung Kim, Rafiqul Islam, Nina Hong, Cosmin-Constantin Popescu, Sara Makarem, Tian Gu, Juejun Hu, Patrick E. Hopkins
Summary: This paper investigates the optical and thermal properties of three phase change materials and provides necessary parameters for modeling PCM based photonic devices. The results show that Sb2Se3 and Sb2S3 have low extinction coefficients in the infrared spectrum and their thermal conductivity increases significantly upon phase transformation.
OPTICAL MATERIALS EXPRESS
(2023)
Article
Chemistry, Multidisciplinary
Teng-Fei Lu, Shriya Gumber, Marina V. Tokina, John A. Tomko, Patrick E. Hopkins, Oleg V. Prezhdo
Summary: Thermal transport at nanoscale metal-semiconductor interfaces via electron-phonon coupling plays a crucial role in modern microelectronic, electro-optic, and thermoelectric devices. This study demonstrates that incorporating a thin Ti adhesion layer at the Au/WSe2 interface can enhance the hot electron and hole relaxation rates due to enhanced electron-phonon coupling. The results provide insights for improving the design of materials at metal-semiconductor interfaces by optimizing heat dissipation.
