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Search Publications by: Curt A. Richter (Fed)

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Displaying 26 - 50 of 238

Magnetotransport in highly enriched 28Si for quantum information processing devices

November 25, 2018
Author(s)
Aruna N. Ramanayaka, Ke Tang, Joseph Hagmann, Hyun S. Kim, Curt A. Richter, Joshua M. Pomeroy
Elimination of unpaired nuclear spins can result in low error rates for quantum computation; therefore, isotopically enriched 28Si is regarded as an ideal environment for quantum information processing devices. Using mass selected ion beam deposition

Contact and Non-Contact Measurement of Electronic Transport in Individual 2D SnS Colloidal Semiconductor Nanocrystals

September 24, 2018
Author(s)
Adam J. Biacchi, Son T. Le, Brian G. Alberding, Joseph A. Hagmann, Sujitra J. Pookpanratana, Edwin J. Heilweil, Curt A. Richter, Angela R. Hight Walker
Colloidal-based solution syntheses offer a scalable and cost-efficient means of producing 2D nanomaterials in high yield. While much progress has been made towards the controlled and tailorable synthesis of semiconductor nanocrystals in solution, it

Controllable Wide-range n- and p-Doping of Monolayer Group 6 Transition-metal Disulfides and Diselenides

July 30, 2018
Author(s)
Siyuan Zhang, Heather M. Hill, Curt A. Richter, Angela R. Hight Walker, Barlow Stephen, Seth Marder, Christina A. Hacker, Sujitra J. Pookpanratana
Developing processes to controllably dope transition-metal dichalcogenides (TMDs) is critical to achieving commercial integration for optical and electrical applications. In this study, molecular reductants and oxidants are introduced onto a series of

Towards superconductivity in p-type delta-doped Si/Al/Si heterostructures

July 30, 2018
Author(s)
Aruna N. Ramanayaka, Hyun Soo Kim, Joseph A. Hagmann, Roy E. Murray, Ke Tang, Neil M. Zimmerman, Curt A. Richter, Joshua M. Pomeroy, Frederick Meisenkothen, Huairuo Zhang, Albert Davydov, Leonid A. Bendersky
In pursuit of superconductivity in p-type silicon (Si), we are using a single atomic layer of aluminum (Al) sandwiched between a Si substrate and a thin Si epi-layer. The delta layer was fabricated starting from an ultra high vacuum (UHV) flash anneal of

Calibration and impact of bulk trap-assisted tunneling and Shockley-Read-Hall currents in InGaAs tunnel-FETs

September 1, 2017
Author(s)
Quentin Smets, Anne S. Verhulst, Eddy Simoen, David J. Gundlach, Curt A. Richter, Nadine Collaert, Marc Heyns
The tunnel-FET (TFET) is a promising candidate for future low-power logic applications because it enables a sub-60 mV/dec subthreshold swing. However, most experimental TFETs are plagued by unwanted trap-assisted tunneling (TAT) and Shockley-Read-Hall (SRH

Epitaxially-grown self-assembled Bi2Se3/Bi2MnSe4 multilayer heterostructures

August 14, 2017
Author(s)
Joseph A. Hagmann, Xiang Li, Si-Ning Dong, Sergei Rouvimov, Sujitra J. Pookpanratana, Kin Man Yu, Tatyana Orlova, Curt A. Richter, David G. Seiler, Xinyu Liu, Jacek K. Furdyna, Margaret Dobrowolska
Progress in understanding topologically non-trivial systems offers the promise of predicting novel systems that demonstrate the remarkable properties associated with topological systems, such as unidirectional spin-polarized surface current and the

Towards single atom devices for quantum information and metrology: weak localization in embedded phosphorus delta layers in silicon

June 29, 2017
Author(s)
Joseph A. Hagmann, Xiqiao Wang, Pradeep N. Namboodiri, Jonathan E. Wyrick, Roy E. Murray, Michael D. Stewart, Richard M. Silver, Curt A. Richter
The key building block for devices based on the deterministic placement of dopants in silicon is the formation of phosphorus dopant monolayers and the overgrowth of high quality crystalline Si. Lithographically defined dopant delta-layers can be formed

Interacting nanoscale magnetic cluster arrays in molybdenum oxide bronzes

May 26, 2017
Author(s)
Joseph A. Hagmann, Son T. Le, Lynn F. Schneemeyer, Joseph A. Stroscio, Tiglet Besara, Theo Siegrist, Curt A. Richter, David G. Seiler
In this study, we examine several reduced ternary molybdates in the family of rare earth molybdenum bronzes produced by electrochemical synthesis with composition LnMo16O44. These compounds contain an array of electrically isolated but magnetically

Electrical stabilization of surface resistivity in epitaxial graphene systems by amorphous boron nitride encapsulation

May 25, 2017
Author(s)
Albert F. Rigosi, Chieh-I Liu, Nicholas R. Glavin, Yanfei Yang, Heather M. Hill, Jiuning Hu, Angela R. Hight Walker, Curt A. Richter, Randolph E. Elmquist, David B. Newell
Homogeneous monolayer epitaxial graphene (EG) is an ideal candidate for the development of millimeter-sized devices with single-crystal domains. A clean fabrication process was used to produce EG-based devices with n-type doping level of order 10^12 cm^-2

Preservation of surface conductivity and dielectric loss tangent in large-scale, encapsulated epitaxial graphene measured by non-contact microwave cavity perturbations

May 19, 2017
Author(s)
Albert F. Rigosi, Nicholas R. Glavin, Chieh-I Liu, Yanfei Yang, Jan Obrzut, Heather M. Hill, Jiuning Hu, Hsin Y. Lee, Angela R. Hight Walker, Curt A. Richter, Randolph E. Elmquist, David B. Newell
Regarding the improvement of current quantized Hall resistance (QHR) standards, one promising avenue is the growth of homogeneous monolayer epitaxial graphene (EG). A clean and simple process was used to produce large, precise areas of EG. Properties like

Cryogenic pulsed I-V measurements on homo- and heterojunction III-V TFETs

April 1, 2017
Author(s)
Quentin Smets, Jihong Kim, Jason Campbell, David M. Nminibapiel, Dmitry Veksler, Pragya Shrestha, Rahul Pandey, Anne S. Verhulst, Eddy Simoens, David J. Gundlach, Curt A. Richter, Kin P. Cheung, Suman Suman, Anda Mocuta, Nadine Collaert, Aaron Thean, Marc Heyns
Most experimental reports of tunneling field-effect transistors show defect-related performance degradation. Charging of oxide traps causes Fermi level pinning, and Shockley-Read-Hall (SRH)/trap-assisted tunneling (TAT) generation cause unwanted leakage

Elucidating the Structural and Electronic Properties of Solution-Synthesized 2D SnS Crystals

March 28, 2017
Author(s)
Adam J. Biacchi, Brian G. Alberding, Son T. Le, Joseph A. Hagmann, Sugata Chowdhury, Curt A. Richter, Edwin J. Heilweil, Angela R. Hight Walker
The vast majority of nanoscale 2D materials are synthesized by exfoliation or gas phase deposition techniques. Alternatively, bottom-up colloidal solution syntheses offer a scalable and cost-efficient means of producing 2D nanomaterials in high yield

Trapping States of Mixed-Isomer Organic Semiconductors within Organic Field-Effect Transistors

December 14, 2016
Author(s)
Peter Diemer, Jacori Hayes, Evan Welchman, Rawad Hallani, Sujitra Pookpanratana, Christina Hacker, Curt A. Richter, Timo Thonhauser, Oana Jurchescu
Organic field effect transistor (OFET) performance is dictated by the composition and geometry of the device, as well as the quality of the organic semiconductor (OSC) film, which strongly depends on the purity and structural defects. When present, these

Atomically precise device fabrication

December 7, 2016
Author(s)
Joseph A. Hagmann, Xiqiao Wang, Pradeep N. Namboodiri, Richard M. Silver, Curt A. Richter
An improved capacity to control matter at the atomic scale is central to the advancement of nanotechnology. The complementary metal-oxide-semiconductor (CMOS) devices that power existing computing technology, which continue to scale down in size as

Integration of Redox-Active Diruthenium-based Molecular Layer onto Electrodes for Memory Device Applications

November 10, 2016
Author(s)
Sujitra J. Pookpanratana, Hao Zhu, Joseph W. Robertson, Sean Natoli, Emily G. Bittle, Curt A. Richter, Tong Ren, Qiliang Li, Christina A. Hacker
Attaching and integrating electrochemically-active molecules to a variety of different surfaces is of importance for applications in catalysis, memory devices, and molecular electronics. With the increasing demand for personal electronics, growth in Flash

Calibration of Effective Tunneling Bandgap in GaAsSb/InGaAs for improved TFET Performance Prediction

November 3, 2016
Author(s)
Quentin Smets, Anne S. Verhulst, Salim El Kazzi, David J. Gundlach, Curt A. Richter, Anda Mocuta, Nadine Collaert, Aaron Thean, Marc Heyns
The effective bandgap for heterojunction band-to-band tunneling (Eg,eff) is a crucial design parameter for heterojunction TFET. However, there is significant uncertainty on Eg,eff, especially for In0.53Ga0.47As/GaAs0.5Sb0.5. This makes TFET performance

Polymorphism in the 1:1 Charge-Transfer Complex DBTTF-TCNQ and Its Effects on Optical and Electronic Properties

September 14, 2016
Author(s)
Katelyn Goetz, Jun?ya Tsutsumi, Sujitra Pookpanratana, Jihua Chen, Curt A. Richter, Christina Hacker, Tatsuo Hasegawa, Oana Jurchescu
The organic charge-transfer (CT) complex dibenzotetrathiafulvalene - 7,7,8,8-tetracyanoquinodimethane (DBTTF-TCNQ) is found to crystallize in two polymorphs when grown by physical vapor transport: the known α-polymorph and a new structure, the β-polymorph

Field Effects of Current Crowding at Metal-MoS2 Contacts

March 10, 2016
Author(s)
Hui H. Yuan, Guangjun Cheng, Sheng Yu, Angela R. Hight Walker, Curt A. Richter, Qiliang Li
Gate assisted contact-end Kelvin test structures and gate assisted 4-probe structures have been designed and fabricated to measure the field effects of current crowding at the source/drain contacts of top-gate MoS2 field effect transistors. The transistors

Non-volatile Memory Devices with Redox-active Diruthenium Molecular Compound

February 12, 2016
Author(s)
Sujitra J. Pookpanratana, Hao Zhu, Emily G. Bittle, Sean Natoli, Tong Ren, Curt A. Richter, Qiliang Li, Christina A. Hacker
Non-volatile Flash-based memory devices, which incorporate a novel redox-active diruthenium molecule, is demonstrated. The memory device is in a capacitor structure, metal/oxide/molecule/oxide/silicon, where the diruthenium molecule is covalently attached