Article
Chemistry, Physical
Sami Ullah, Gary Wan, Christos Kouzios, Cameron Woodgate, Mattia Cattelan, Neil Fox
Summary: Wideband gap diamond-based materials are being studied for energy harvesting and quantum applications, with Sn identified as a potential candidate for negative electron affinity on diamond surfaces. Experimental results show that SnO termination on diamond surfaces can lead to NEA and reduce the work function, making it a stable option for device applications. The intercalation of Li with SnO planes enhances the stability of LiO termination on diamond surfaces and reduces the work function even further, showing potential for more efficient diamond surface terminations.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
Egor Ukraintsev, Alexander Kromka, Wiebke Janssen, Ken Haenen, Daisuke Takeuchi, Petr Babor, Bohuslav Rezek
Summary: By surface treatment using electrochemically grown polypyrrole, the secondary-electron emission and photoelectron emission from boron-doped diamond are enhanced, surpassing the electron emission intensity from the hydrogen-terminated surface with negative electron affinity. This enhancement is stable for at least one month in air and persists in vacuum even after thermal annealing.
Article
Physics, Applied
Yu Yang, Franz A. Koeck, Xingye Wang, Robert J. Nemanich
Summary: A thin layer of Al2O3 was used as an interface layer to increase the hole mobility of diamond, reduce Coulomb scattering, and improve material performance.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Physical
Ramiz Zulkharnay, Neil L. Allan, Paul W. May
Summary: Surface modification of diamond with the addition of metals or other electropositive adsorbates can result in negative electron affinity (NEA). Scandium adsorption on diamond is energetically favorable, especially on the oxygenated surface. Most stable scandium adsorption configurations possess NEA, with the highest NEA value found on the oxygenated diamond surface.
Article
Physics, Condensed Matter
Sun Zhaolong, Gao Nan
Summary: In this study, the structural stabilities and electronic properties of boron (B)–nitrogen (N) co-terminated diamond (110) surface were investigated using first-principles calculations. It was found that the H/F mixed (H/F = 1.0) adsorption surface was dynamically and thermally stable, and exhibited no surface spin noise or surface-related state. Additionally, it had a positive electron affinity of 1.11 eV, making it a promising candidate for NV-based quantum sensors.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Materials Science, Multidisciplinary
Zhaolong Sun, Bo Cui, Pingping Liang, Qimeng Liu, Nan Gao, Hongdong Li
Summary: This study explores the potential of hafnium (Hf) terminated diamond surfaces in achieving negative electron affinity (NEA). By using swarm-intelligence structural search and first-principles calculations, the researchers found that Hf-terminated diamond surfaces exhibit stable NEA properties and high thermal stability, making them promising candidate materials for electron emission applications.
DIAMOND AND RELATED MATERIALS
(2024)
Article
Chemistry, Physical
Yan-Feng Wang, Wei Wang, Jinjia Wei, Bo Jiao, Defei Xu, Xiaohui Chang, Haris Naeem Abbasi, Wangzhen Song, Genqiang Chen, Hong-Xing Wang
Summary: A novel method of electrochemically modifying hydrogen-terminated diamond surface with LiF dielectric in MISFETs was proposed in this communication, resulting in the formation of CeF bonds. A model was introduced to explain the electrochemistry modification on MISFETs, with the theoretical electrolysis voltage of F- calculated to be around 3.8V in line with the experimental value of -5V.
Article
Nanoscience & Nanotechnology
Chenxi Li, Eliezer F. Oliveira, Abhijit Biswas, Anand B. Puthirath, Xiang Zhang, Atin Pramanik, Elias J. Garratt, Mahesh R. Neupane, Bradford B. Pate, Anthony Glen Birdwell, Tony G. Ivanov, Tanguy Terlier, Robert Vajtai, Pulickel M. Ajayan
Summary: Diamond surface functionalization has attracted significant research interest, particularly H-termination due to its ability to enhance surface conductivity. This study focused on exploring the attachment of different functional groups, such as nitrogen and sulfur heteroatoms, on the diamond surface and their impact on electronic structure. The functionalized diamond surfaces were found to possess higher conductivity than H-terminated diamonds and showed a downshift in the conduction band minimum and valence band maximum, indicating a reduced bandgap. These findings suggest the potential of heteroatom functionalizations on diamond surfaces for various electronic applications.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Tetsuya Tatsuishi, Kyotaro Kanehisa, Taisuke Kageura, Takahiro Sonoda, Yuki Hata, Kazuto Kawakatsu, Takashi Tanii, Shinobu Onoda, Alastair Stacey, Shozo Kono, Hiroshi Kawarada
Summary: This paper presents a new methodology for fabrication of 2D aligned NV ensembles by using pure diamond growth and high nitrogen coverage on (111) surface. The resulting 2D NV ensembles have high alignment ratio and long coherence time. Introducing thermal annealing of the nitrogen termination improves alignment rate.
Article
Chemistry, Physical
Luyu Shang, Guoying Bai
Summary: In this study, we investigated how halogen chemistry surfaces control the nucleation of CaCO3 by constructing halogen-terminated self-assembled monolayers and measuring the nucleation kinetic/thermodynamic parameters. We found that the abilities of halogen chemistry surfaces to promote CaCO3 nucleation are determined by either thermodynamic or kinetic control, depending on the supersaturation range.
APPLIED SURFACE SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
V. Serpente, A. Bellucci, M. Girolami, M. Mastellone, S. Iacobucci, A. Ruocco, D. M. Trucchi
Summary: The study investigates the homogeneity of hydrogen termination on single-crystal CVD diamond surfaces exposed to air using a combination of sheet resistance measurements and electron reflectivity measurements. The coherence between the spatial distributions of sheet resistance and electron reflectivity maps, along with their consistency with an electron energy loss analysis, shows that this combined approach provides a reliable and easy evaluation of the effectiveness and homogeneity of the hydrogen-termination process on a diamond surface.
DIAMOND AND RELATED MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Patrick R. Raffaelle, George T. Wang, Alexander A. Shestopalov
Summary: The focus of this study was to demonstrate the vapor-phase halogenation of Si(100) and evaluate the inhibiting ability of the halogenated surfaces towards atomic layer deposition of aluminum oxide (Al2O3). The results showed that halogenated surfaces effectively inhibited the formation of aluminum oxide, with chlorinated surfaces exhibiting the best stability.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Xinchang Wang, Yu Qiao, Karin Larsson, Fanghong Sun
Summary: In this study, H-, O-, OH-, and F-terminated N-doped diamond surfaces were calculated using density functional theory, revealing that the N dopant has different effects depending on its position and the terminating species. The adsorption energy is decreased when the N dopant is in the first carbon layer, while it is slightly increased when in the second carbon layer. Oxygen shows the highest reactivity to attacks, and N dopants have slight influences on the reactivity of adjacent adsorbates.
MATERIALS CHEMISTRY AND PHYSICS
(2021)
Review
Materials Science, Multidisciplinary
Chen Liu, Ning Jia, Ji-zhou Zhai, Peng-zhen Zhao, Peng-fei Guo, Hong-qiang Wang
Summary: This study investigates the possibility of enhancing the flexibility and stability of perovskite films by embedding laser-derived carbon dots with halogen-terminated surfaces at the interfaces between grains. The strong interaction between the perovskite and carbon dots leads to improved defect passivation, lattice anchoring, and carrier dynamics, resulting in flexible solar cells with high power conversion efficiencies and long-term stability.
NEW CARBON MATERIALS
(2022)
Article
Chemistry, Physical
Sen Zhang, Kang Liu, Benjian Liu, Xiaohui Zhang, Pengfei Qiao, Jiwen Zhao, Yicun Li, Xiaobin Hao, Ying Liang, Bo Liang, Wenchao Zhang, Bing Dai, Jiecai Han, Jiaqi Zhu
Summary: Surface potential pinning effect is a common rule in semiconductor materials, which can have a significant impact on device performance. However, this effect is often overlooked when studying diamond devices. In this study, we investigated the contact band diagram between metals with different work functions and oxygen terminated diamond. The results showed that the oxygen terminal can pin the Schottky barrier height. Additionally, the symmetrical photocurrent-voltage characteristics observed in the experiment further support this conclusion.
Meeting Abstract
Gastroenterology & Hepatology
Ann-Marie Baker, Chang Ho R. Choi Hayley Davis, Ibrahim Al-Bakir, Pierre Martinez, Daniel Temko, William Cross, Marc Williams, Sujata Biswas, Stuart A. McDonald, Nicholas A. Wright, Ian Tomlinson, Morgan Moorghen, Stephen Hayes, Manuel Rodriguez-Justo, Andrew Silver, Lai Mun Wang, Marnix Jansen, Ailsa Hart, Simon Leedham, Trevor A. Graham
Article
Engineering, Electrical & Electronic
F. Arith, J. Urresti, K. Vasilevskiy, S. Olsen, N. Wright, A. O'Neill
IEEE ELECTRON DEVICE LETTERS
(2018)
Review
Chemistry, Multidisciplinary
Nicholas J. Wright, Seok-Yong Lee
Summary: Nucleosides, essential in various life processes, rely on specific transport systems to cross biological membranes. Humans have two unrelated protein families mediating nucleoside membrane transport. This review provides an overview of nucleoside transport research, focusing on their roles in human health, recent structural advancements, and pharmacological features.
Article
Multidisciplinary Sciences
Brian M. Wood, Riccardo S. Millar, Nicholas Wright, Joshua Baumgartner, Hannah Holmquist, Christian Kiffner
Summary: This study assessed mammal populations in a semi-arid savannah in northern Tanzania, recording 36 wild mammal species. The range of relative abundance indices suggests unequal distribution of wildlife in the area. Comparison with a fully protected national park showed higher detection rates of wild herbivores and carnivores in the park, while livestock were more abundant in the Hadza-occupied region.
Article
Mathematics, Applied
Graham A. Niblo, Nick Wright, Jiawen Zhang
Summary: This paper establishes a new combinatorial framework for the study of coarse median spaces, bridging the worlds of asymptotic geometry, algebra, and combinatorics. It introduces a simple and entirely algebraic notion of coarse median algebra that generalizes the concepts of bounded geometry coarse median spaces and classical discrete median algebras. The paper focuses on the perspective of intervals in studying the coarse median universe, with cardinality as a proxy for distance, and shows that the metric on a quasi-geodesic coarse median space of bounded geometry can be constructed using only the coarse median operator. Additionally, it develops a concept of rank for coarse median algebras in terms of the geometry of intervals, providing a higher dimensional analogue of Gromov's concept of delta-hyperbolicity.
SELECTA MATHEMATICA-NEW SERIES
(2021)
Article
Computer Science, Software Engineering
Taylor Groves, Naveen Ravichandrasekaran, Brandon Cook, Noel Keen, David Trebotich, Nicholas J. Wright, Bob Alverson, Duncan Roweth, Keith Underwood
Summary: Message matching is an important performance consideration for applications with two-sided semantics. This study presents an instrumentation of the CrayMPI library for collecting detailed message-matching statistics and an implementation of hashed matching in software. The authors analyze DOE applications with complex communication patterns to determine when hardware offload capabilities within the NIC can accelerate message matching.
CONCURRENCY AND COMPUTATION-PRACTICE & EXPERIENCE
(2023)
Article
Astronomy & Astrophysics
Alexis L. Quintana, Nicholas J. Wright
Summary: This study reexamines the existence and membership of the Cygnus OB associations, identifying six new associations with two resembling the historical Cyg OB2 and OB3. The properties of the new associations and their expansion trends are consistent with typical values for OB associations. Large-scale kinematic expansion patterns across the Cygnus region are attributed to feedback from previous generations of stars.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Ergonomics
Nicholas A. Wright, La-Troy Lee
Summary: In the United States, approximately 28 lives are lost daily in motor vehicle accidents involving alcohol-impaired drivers. Despite various traffic laws enacted by most states to tackle this issue, there is little consensus on their effectiveness in reducing alcohol-induced fatalities. This paper uses quasi-random variation in state-level laws to estimate the causal impact of alcohol-related traffic laws on the frequency of fatal accidents, highlighting potential biases in traditional estimation methods.
ACCIDENT ANALYSIS AND PREVENTION
(2021)
Proceedings Paper
Computer Science, Hardware & Architecture
Glenn K. Lockwood, Alberto Chiusole, Nicholas J. Wright
Summary: Researchers conducted a preliminary evaluation of a storage system from VAST Data, and found that traditional I/O performance measurement techniques struggle to properly characterize all-flash storage systems. They proposed alternative methods to better reflect the performance that real workflows can expect.
PROCEEDINGS OF IEEE/ACM SIXTH INTERNATIONAL PARALLEL DATA SYSTEMS WORKSHOP (PDSW 2021)
(2021)
Proceedings Paper
Computer Science, Hardware & Architecture
Sridutt Bhalachandra, Brian Austin, Nicholas J. Wright
Summary: This study investigates the factors affecting power consumption of the NERSC Cori supercomputer at different levels, identifying node-level and system-level power influences, and revealing potential areas for optimization.
PROCEEDINGS OF PERFORMANCE MODELING, BENCHMARKING AND SIMULATION OF HIGH PERFORMANCE COMPUTER SYSTEMS (PMBS 2021)
(2021)
Proceedings Paper
Computer Science, Hardware & Architecture
Khaled Z. Ibrahim, Tan Nguyen, Hai Ah Nam, Wahid Bhimji, Steven Farrell, Leonid Oliker, Michael Rowan, Nicholas J. Wright, Samuel Williams
Summary: This work introduces a new methodology for developing detailed performance understanding of ML benchmarks, emphasizing the importance of efficiently leveraging ML techniques on high-performance computing systems. The study explores emerging SciML benchmark applications in cosmology, climate, and image classification, developing and validating performance models to improve SciML design and system efficiency. Insights from this research will help computer architects and data scientists understand performance bottlenecks and optimization opportunities in the field of scientific machine learning.
PROCEEDINGS OF PERFORMANCE MODELING, BENCHMARKING AND SIMULATION OF HIGH PERFORMANCE COMPUTER SYSTEMS (PMBS 2021)
(2021)
Article
Meteorology & Atmospheric Sciences
Mary Ann Cunningham, Nicholas S. Wright, Penelope B. Mort Ranta, Hannah K. Benton, Hassan G. Ragy, Christopher J. Edington, Chloe A. Kellner
Summary: Climate models project vulnerability to global warming in low-income regions, particularly impacting smallholder cash crops like rainfed cotton in West Africa. Suitable areas for rainfed cotton in the region are expected to decline significantly by 2050, with precipitation and temperature changes as key drivers. Adaptation to these changes and progress on sustainable development goals will require global support and cooperation.
Article
Economics
Nicholas A. Wright
Summary: Research shows that students who receive need-based grants or student loans perform better academically and have higher graduation rates, as well as a higher likelihood of remaining in college beyond the second year. Both programs lead treated students to reduce their engagement in the labor market during college, but have opposing impacts on students' earnings in the early years after their expected graduation date.
JOURNAL OF DEVELOPMENT ECONOMICS
(2021)
Article
Mathematics
Jan Spakula, Nick Wright
ALGEBRAIC AND GEOMETRIC TOPOLOGY
(2017)
Meeting Abstract
Oncology
Ann-Marie Baker, Mindy Wang, Xiao-Jun Ma, Courtney Anderson, Weini Huang, Enric Domingo, Annabelle Lewis, John Bridgewater, Marnix Jansen, Nicholas A. Wright, Manuel Rodriguez-Justo, Emily Park, Ian Tomlinson, Trevor A. Graham
