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Search Publications by

Jeffrey Fagan (Fed)

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Displaying 1 - 25 of 79

DNA-directed nanofabrication of high-performance carbon nanotube field-effect transistors

May 22, 2020
Ming Zheng, Jeffrey A. Fagan, Jason K. Streit, Mengyu Zhao, Yahong Chen, Kexin Wang, Zhi Zhu, Wei Sun
Scaling the channel pitch of field-effect transistors (FETs) is one prerequisite towards future ultra-scaled technology nodes. While lithography has been the foundational tool during the scaling of bulk materials, bio- fabrication is promising for

Precise pitch-scaling of ultra-scaled carbon nanotube arrays within 3D DNA nano-trenches

May 22, 2020
Jason K. Streit, Jeffrey Fagan, Ming Zheng, Wei Sun, Peng Yin, Jie Shen, Zhao Zhao, Hareem Maune
Precise assembly of carbon nanotubes (CNTs) into densely-aligned uniformly parallel arrays has been the missing link towards the emerging ultra-scaled post-Si technology nodes specified in the International Technology Roadmap for Semiconductors (ITRS)

Separation of Specific Single Enantiomer Single-Wall Carbon Nanotubes in the Large Diameter Regime

November 19, 2019
Jeffrey A. Fagan, Ming Zheng, Sofie Cambre, Wim Wenseleers, Benjamin Flavel, Han Li, Stephanie Reich, Georgy Gordeev, Oisin Garrity, Naga Peyyety, Ralph Krupke, Pranauv Selvasundaram
Enantiomer level isolation of single-wall carbon nanotubes (SWCNTs) in high concentration and purity for nanotubes greater than 1.1 nm in diameter is demonstrated for the first time using a twostage aqueous two-phase extraction (ATPE) technique. In total 5

Global alignment of solution-based single-wall carbon nanotube films via machine-vision controlled filtration

September 11, 2019
Jeffrey A. Fagan, Angela R. Hight Walker, Adam J. Biacchi, Joshua S. Walker, William D. Rice, Thomas Searles, Valerie A. Kuehl
Over the past decade, substantial progress has been made in the chemical processing (chiral enrichment, length sorting, handedness selectivity, and filling substance) of single- wall carbon nanotubes (SWCNTs). Recently, it was shown that large

Structural Insights into DNA-Stabilized Silver Clusters

May 10, 2019
Danielle Schultz, Robert G. Brinson, Fahriye N. Sari, Jeffrey Fagan, Christina Bergonzo, Nancy Lin, Joy Dunkers
The structure and dynamics of Ag complexes derived from single stranded DNA (ssDNA) is less understood than their double stranded (dsDNA) counterparts despite their great promise as fluorescent biological probes and sensors. In this work, we seek new

Metrological Assessment of Single-Walled Carbon Nanotube Materials by Optical Methods

March 1, 2019
Jeffrey A. Fagan, Angela R. Hight Walker, Ming Zheng, Lefebvre Jacques, Paul Finnie
This chapter discusses the metrology – i.e. the science of measurement – of single-wall carbon nanotubes (SWCNTs) with optical methods. Professor Mildred (“Millie”) Dresselhaus was a strong advocate for nanotube metrology and a pioneer in carbon nanotube

Defect Evolution of Ion-Exposed Single-Wall Carbon Nanotubes

January 3, 2019
Jana Kalbacova, Elias J. Garratt, Raul D. Rodriguez, Angela R. Hight Walker, Kevin A. Twedt, Jeffrey Fagan, Teresa I. Madeira, Jabez J. McClelland, Babak Nikoobakht, Dietrich R. Zahn
A systematic evaluation of defects is essential to understand and engineer device properties and applications. Raman spectroscopy is employed for the characterization of carbon nanomaterials in particular to quantitatively evaluate defects from the

In-situ near-field probe microscopy of plasma processing

December 27, 2018
Alexander Tselev, Jeffrey Fagan, Andrei Kolmakov
There exists a great necessity for in situ nanoscale characterization of surfaces and thin films during plasma treatments. To address this need, the current approaches rely on either ‘post mortem' sample microscopy, or in situ optical methods. The latter

Nanoparticle Manufacturing - Heterogeneity through Processes to Products

August 15, 2018
Samuel M. Stavis, Jeffrey Fagan, Michael Stopa, James Alexander Liddle
Commercial products are now making use of the unique properties of nanoscale particles. However, common challenges of making nanoparticles into products still limit their impact. In this article, we review recent advances in nanoparticle manufacturing in

A radial calibration window for analytical ultracentrifugation

July 20, 2018
Thomas W. LeBrun, Peter Schuck, Wei Ren, Justine Yoon, Xianghui Dong, Nicole Y. Morgan, Jeffrey Fagan, Huaying Zhao
Analytical ultracentrifugation (AUC) is a first-principles based method for studying particles in solution by monitoring the evolution of their radial concentration distribution as a function of time in the presence of a high centrifugal field. In

Alkane Encapsulation Induces Strain in Small Diameter Single-Wall Carbon Nanotubes

May 4, 2018
Jason K. Streit, Jochen I. Campo, Chad R. Snyder, Ming Zheng, Jeffrey R. Simpson, Angela R. Hight Walker, Jeffrey Fagan
Encapsulation of linear alkane molecules in the endohedral volumes of small diameter single- wall carbon nanotubes (SWCNTs) is shown to induce diameter dependent strain on the hexagonal lattice of carbon atoms composing the tubular structure. For the

A Low Energy Route to DNA-wrapped Carbon Nanotubes via Replacement of Bile Salts

August 31, 2017
Ming Zheng, Jason K. Streit, Jeffrey A. Fagan
DNA-wrapped carbon nanotubes are a class of bio-nano hybrid molecules that exhibit extended bonding structures and have enabled carbon nanotube sorting, controlled assembly, and biosensing and bioimaging applications. The current method of synthesizing

Progress towards total structure control in SWCNT populations

May 14, 2017
Jeffrey A. Fagan
As-synthesized single-wall carbon nanotube (SWCNT) populations contain substantial distributions of SWCNT structures, including in the distribution of species ((n,m) chiralities) and enantiomers (i.e. the handedness of the lattice vector), as well as in

Separation of Double-Wall Carbon Nanotubes by Electronic Type and Diameter

January 24, 2017
Jason K. Streit, Stephanie Lam, Yanmei Piao, Angela R. Hight Walker, Jeffrey A. Fagan, Ming Zheng
In this work, we introduce a new procedure for the efficient isolation and subsequent separation of double-wall carbon nanotubes (DWCNTs). A simplified rate zonal ultracentrifugation (RZU) process is first applied to obtain samples of highly enriched

Differentiating Left- and Right-Handed Carbon Nanotubes by DNA

December 28, 2016
Ming Zheng, Geyou Ao, Jason K. Streit, Jeffrey A. Fagan
The emergence of macromolecules of defined structures is a crucial step in the evolution of life. The mechanism by which these structures are selected from astronomical numbers of biopolymer sequences has long been a topic of controversy1,2. Experimenting

Enhancing Single-Wall Carbon Nanotube Properties Through Controlled Endohedral Filling

May 10, 2016
Jochen I. Campo, Yanmei Piao, Stephanie Lam, Christopher Stafford, Jason K. Streit, Jeffrey R. Simpson, Angela R. Hight Walker, Jeffrey Fagan
Chemical control of the endohedral volume of single-wall carbon nanotubes (SWCNTs) via liquid-phase filling is demonstrated to be a facile strategy to controllably modify properties of the nanotubes in manners significant for processing and proposed

Quantification of carbon nanotubes in environmental matrices: Current capabilities, case studies, and future improvements

April 6, 2016
Elijah J. Petersen, D. X. Flores-Cervantes, Thomas Bucheli, Lindsay C. Elliott, Jeffrey A. Fagan, Alexander Gogos, Shannon Hanna, Antonio R. Montoro Bustos, Desiree L. Plata, Vytautas Reipa, Paul Westerhoff, Michael R. Winchester, Elisabeth Mansfield
Carbon nanotubes (CNTs) have numerous exciting potential applications approaching commercialization. As such, quantitative measurements of CNTs in key environmental matrices (water, soil, sediment, and biological tissues) are needed to address concerns

The Nature of Record Efficiency Fluid-Processed Nanotube-Silicon Heterojunctions

April 20, 2015
Jeffrey A. Fagan, Erik K. Hobbie, John M. Harris, Matthew R. Semler
The dark transport characteristics of heterojunctions assembled from type, chirality and length-purified single-wall carbon nanotubes (SWCNTs) are used to clarify the nature of nanotube-silicon diodes and solar cells. The freestanding films show remarkable

How Large Can We Go? Isolation of > 1 nm Diameter Single-Wall Carbon Nanotubes Species using Aqueous Two Phase Extraction

April 14, 2015
Jeffrey A. Fagan, Erik Haroz, Rachelle Ihly, Hui Gui, Jeffrey Blackburn, Jeffrey R. Simpson, Stephen K. Doorn, Stephanie Lam, Angela R. Hight Walker, Ming Zheng
We demonstrate the effective separation of near-monochiral single-wall carbon nanotube (SWCNT) species with diameters > 1 nm through multi-stage aqueous two phase extraction (ATPE), and report an empirical function for the surfactant concentrations at