Research

Our goal is to develop and demonstrate ‘designer’ cold cathode electron sources with tunable parameters (bandgap, efficiency, optical absorption) that outperform present technologies by an order of magnitude in terms of efficiency and lifetime, where success in either of these metrics is considered transformational.

We introduce fundamentally new approaches to address decadal weaknesses in performance and enable cathode properties to be tuned or engineered for specific DOE/LANL missions and related applications. The comprehensive nature of this project requires a focused multi-path, multi-disciplinary approach.

Robustness and lifetime extension

The goal is to engineer two-dimensional (2D) membranes, such as graphene, to serve as a transparent gas barrier shield that does not hinder photoemission but does isolate the cathode surface from reactive gas species without physical damage induced by the high current density electron beam, thus preventing contamination and yielding longer lifetime.

Integrated tests and demonstration

We ensure that performance gains using our novel photocathode concepts are cast within the framework of realistic cathode design and the constraints of a vacuum environment.

We also mature and integrate theoretical photoemission models that account for and predict the effect of the above techniques on local electron density function and other parameters which determine photoemissivity. Measurement of quantum efficiency, spectral response, lifetime, and emittance add to the multiple material characterization techniques to provide a comprehensive picture of cathode performance.

 

Recent News and Publications

  • Hisato Yamaguchi*, Ryunosuke Yusa, Gaoxue Wang, Michael T Pettes, Fangze Liu, Yasutaka Tsuda, Akitaka Yoshigoe, Tadashi Abukawa, Nathan A Moody, Shuichi Ogawa* "Work function lowering of LaB6 by monolayer hexagonal boron nitride coating for improved photo- and thermionic-cathodes" Applied Physics Letters 122, 141901 (2023). https://aip.scitation.org/doi/full/10.1063/5.0142591
    • Selected as an Editor's Pick
  • Lei Guo*, Fangze Liu, Kazuki Koyama, Nolan Regis, Anna M Alexander, Gaoxue Wang, Jeffrey DeFazio, James A Valdez, Anju Poudel, Masahiro Yamamoto, Nathan A Moody, Yoshifumi Takashima, Hisato Yamaguchi* "Rugged bialkali photocathodes encapsulated with graphene and thin metal film" Scientific Reports 13, 2412 (2023). https://www.nature.com/articles/s41598-023-29374-6
  • Christopher J Knill, Hisato Yamaguchi, Kenji Kawahara, Gaoxue Wang, Enrique Batista, Ping Yang, Hiroki Ago, Nathan Moody, Siddharth Karkare "Near-Threshold Photoemission from Graphene-Coated (110)" Physical Review Applied 19, 014015 (2023). https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.19.014015
  • Christopher J Knill, Stephen Douyon, Kenji Kawahara, Hisato Yamaguchi, Gaoxue Wang, Hiroki Ago, Nathan Moody, Siddharth Karkare “Effects of nonlinear photoemission on mean transverse energy from metal photocathodes” Physical Review Accelerators and Beams 26, 093401 Publisher American Physical Society https://journals.aps.org/prab/abstract/10.1103/PhysRevAccelBeams.26.093401

September

May

  • An articles on our paper (work function lowering of LaB6 by monolayer hexagonal boron nitride coating for improved photo- and thermionic-cathodes) was published in LANL STE Highlights https://www.lanl.gov/science-innovation/science-highlights/2023/2023-04.php#MaterialsScienceandTechnology-3
  • We were invited to present our work under the DOE U.S.-Japan Science and Technology Cooperation Program in High Energy Physics at The 45th meeting of the US-Japan Science and Technology Cooperation Program in High Energy Physics in Hawaii (in-person). The topic was on the use of 2D materials as unique protection layer for bialkali photocathodes. https://indico.physics.lbl.gov/event/2259/
  • Our proposal for the DOE U.S.-Japan Science and Technology Cooperation Program in High Energy Physics on overcoming quantum efficiency-lifetime limit of photocathodes for accelerator beam source by integration of atomically-thin protecting layers has been awarded. The lead U.S. and Japanese institutions are LANL and the High Energy Accelerator Research Organization (KEK), respectively. Congratulations, Hisato!

April

  • Our paper on work function lowering of LaB6 by monolayer hexagonal boron nitride coating for improved photo- and thermionic-cathodes was published in Applied Physics Letters https://aip.scitation.org/doi/full/10.1063/5.0142591. It was selected as an Editor's Pick. This was in collaboration with Prof. Shuichi Ogawa of Nihon Univeristy, Japan. Congratulations, Hisato!
  • LANL internal one-year project on development of novel photocathode for accelerator beam source has been awarded. Congratulations, Hisato and Gaoxue!

March

February

  • Our paper on rugged bialkali photocathodes encapsulated with graphene and thin metal film was published in Scientific Reports https://www.nature.com/articles/s41598-023-29374-6. This was in collaboration with Prof. Lei Guo of Nagoya Univeristy, Japan and Prof. Masahiro Yamamoto of KEK, Japan. Congratulations, Hisato!

January

  • Our paper on Near-Threshold Photoemission from Graphene-Coated (110) was published in Physical Review Applied https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.19.014015. This was in collaboration with Prof. Siddharth Karkare of Arizona State University and Prof. Hiroki Ago of Kyushu University, Japan. Congratulations, Hisato!
  • Jinlin Zhang joined LANL as a postdoctoral associate. Welcome, Jinlin!

Project Members

  • Vitaly Pavlenko (AOT-AE)
  • Anna Alexander (AOT-AE)
  • Jinlin Zhang (AOT-AE)
  • Mark Hoffbauer (C-CDE)
  • Dr. Kevin Jensen (UMD)
  • Dr. John Smedley (SLAC)
  • Dr. Mengjia Gaowei (BNL)
  • Dr. Masahiro Yamamoto (KEK, Japan)
  • Dr. Lei Guo (Nagoya University, Japan)
  • Aditya D. Mohite (LANL->Rice University)
  • Gautam Gupta  (LANL->University of Louisville)
  • Michael Holloway (ISR-4)
  • David Lizon (ISR-4)
  • Jeffrey Pietryga (C-PCS)
  • Istvan Robel (C-PCS)
  • Andrew Shabaev (Naval Research Laboratory)
  • Sam Lambrakos (Naval Research Laboratory)
  • Daniel Finkenstadt (United States Naval Academy)
  • Prof. Prabhakar Bandaru (UCSD)
  • John Lewellen (LANL)
  • Fangze Liu (LANL->China)
  • John Smedley (LANL->SLAC)

News

November

  • Our proposal for the DOE Accelerator R&D and Production (ARDAP) in High Energy Physics on automated growth of photocathodes for accelerator beam source has been awarded for two years. Congratulations, Vitaly!

October

September

  • Nathan Moody gave an invited talk on the use of 2D materials as unique protection layer for bialkali photocathodes and Vitaly Pavlenko gave an invited talk on automated growth of alkali photocathodes at European Workshop on Photocathodes for Particle Accelerator Applications (EWPAA 2022) held in Milan, Italy (presentation via online). https://agenda.infn.it/event/29956

July

  • LANL internal three-year project on development of high-gradient accelerators will start in October! Our role in the project is on the development of photocathodes.

June

  • Hisato Yamaguchi gave an invited talk on the use of 2D materials as unique protection layer for bialkali photocathodes at the 241st Electrochemical Society (ECS) meeting (presentation via online).

May

  • Hisato Yamaguchi presented a poster on the use of 2D materials as unique protection layer for bialkali photocathodes at Materials Research Society (MRS) Spring meeting in Hawaii (in person).

April

  • We were invited to present our work under the DOE U.S.-Japan Science and Technology Cooperation Program in High Energy Physics at their program annual meeting (presentation via online). The topic was on the use of 2D materials as unique protection layer for bialkali photocathodes.

February

  • Our paper on Stoichiometry control and automated growth of alkali antimonide photocathode films by molecular beam deposition was published in Applied Physics Letters https://doi.org/10.1063/5.0080948. Congratulations, Vitaly!

January

December

  • Our paper on Photoemission from Bialkali Photocathodes through an Atomically Thin Protection Layer was published in ACS Appl. Mater. Interfaces doi.org/10.1021/acsami.1c19393. Congratulations, Fangze and Hisato!

October

  • Nathan Moody was elected as prestigious American Physical Society (APS) fellow. Congratulations, Nathan! https://discover.lanl.gov/news/1020-aps-fellows
  • Hisato Yamaguchi gave an invited talk on the use of 2D materials as unique protection layer for bialkali photocathodes at Photocathode Physics for Photoinjectors conference (virtual).

July

  • Vitaly Pavlenko was awarded an interlal exploratory research grant at LANL on growth of epitaxial photocathodes for accelerator beam source. The project will run for 3 years. Congratulations, Vitaly!

June

  • Hisato Yamaguchi gave an invited talk on the use of 2D materials as unique protection layer for bialkali photocathodes at the Japanese Society of Applied Physics (JSAP)-Optica (OSA) joint symposia (virtual).
  • Our paper on Robust method for broadband efficiency enhancement of electron photocathodes using optical interferences was published in AIP Advances https://aip.scitation.org/doi/full/10.1063/5.0050691. Congratulations, Anna!

May

  • Our proposal for the DOE U.S.-Japan Science and Technology Cooperation Program in High Energy Physics on overcoming quantum efficiency-lifetime limit of photocathodes for accelerator beam source by integration of atomically-thin protecting layers has been awarded. The lead U.S. and Japanese institutions are LANL and the High Energy Accelerator Research Organization (KEK), respectively. Congratulations, Hisato!

December

  • Hisato Yamaguchi gave an invited talk on the use of 2D materials as unique protection layer for bialkali photocathodes at the Japanese Beam Physics Society Workshop (virtual).

October

July

June

May

  • Our proposal for the DOE U.S.-Japan Science and Technology Cooperation Program in High Energy Physics on overcoming quantum efficiency-lifetime limit of photocathodes for accelerator beam source by integration of atomically-thin protecting layers has been awarded. The lead U.S. and Japanese institutions are LANL and the High Energy Accelerator Research Organization (KEK), respectively. Congratulations, Hisato!

March

  • Our paper on Angular scattering of protons through ultrathin graphene foils: Application for time-of-flight instrumentation was published in Review of Scientific Instruments https://doi.org/10.1063/1.5134768. Congratulations, Hisato!

February

December

  • Our paper on Quantum Efficiency Enhancement of Bialkali Photocathodes by an Atomically Thin Layer on Substrates was published in physica status solidi (a) by Wiley  https://doi.org/10.1002/pssa.201900501. It was also selected as the front cover  https://doi.org/10.1002/pssa.201970076. Congratulations Hisato!
Pss Featured Body 960x500

 

 November

  • Our R&D 100 Award on Atomic Armor was featured by our industorial collaborator, Photonis. Click here.
  • Our R&D 100 Award on Atomic Armor was featured in LANL News Release.

October

  • Our R&D 100 Award on Atomic Armor was featured in DOE website.https://www.energy.gov/articles/rd-world-magazine-announces-2019-rd-100-winners
  • Our atomically thin protection coating technology, Atomic Armor won prestigious R&D 100 Award!! (Category: IT/Electrical) The technology was also selected as gold medalist in R&D Special Recognition: Market Disruptor - Products. Congratulations, Nathan, Hisato and the team! https://www.rdworldonline.com/2019-rd-100-award-winners-unveiled/
Rd Atomic Featured Body 960x500

 

August

  • US patent on "Tunable quantum confinement and quantum dot photocathode" was granted. Congratulations, Nathan, Jeff, and Istvan! US 10,395,882

July

  • US patent on "Phototcathodes with protective in-situ graphene gas barrier films and method of making the same" was granted. Congratulations, Nathan and Hisato! US 10,354,828
  • Hisato visited our collaborators in Japan at the High Energy Accelerator Research Organization (KEK) and Nagoya University, Japan for the DOE U.S.-Japan Science and Technology Cooperation Program in High Energy Physics project. They had fruitful discussion on future plans!

June

  • Our atomically thin protection coating technology was featured in a local newspaper, Albuquerque Journal. Nice, Hisato! https://www.lanl.gov/newsroom/science-columns/top-columns-and-blogs/2019/abq-journal-stronger-than-steel.php
  • Our paper on Thermal-field and photoemission from meso-and micro-scale features was published in Journal of Applied Physics. Congratulations, Kevin! https://aip.scitation.org/doi/full/10.1063/1.5097149

May

  • Our proposal for the DOE U.S.-Japan Science and Technology Cooperation Program in High Energy Physics [LAB 19-1902] on overcoming quantum efficiency-lifetime limit of photocathodes for accelerator beam source by integration of atomically-thin protecting layers has been awarded. The lead U.S. and Japanese institutions are LANL and the High Energy Accelerator Research Organization (KEK), respectively. Congratulations, Hisato!

April

  • Our atomically thin protection coating technology, Atomic Armor was featured in LANL Science Video. Great job, Nathan and Hisato! https://www.youtube.com/watch?v=S4krKYGUopg&feature=youtu.be

March

  • Science animation on our efforts of protecting photocathodes for accelerator technology has been published on YouTube. Nice job, Hisato and Nathan! https://www.youtube.com/watch?v=rkusTI_45o0
  • Prof. Masao Kuriki of Hiroshima University, Japan visited LANL as a part of the DOE U.S.-Japan Science and Technology Cooperation Program in High Energy Physics collaboration. Thank you for visiting!

February

  • John Smedley joined LANL as a deputy group leader of Accelerators and Electrodynamics (AOT-AE). Welcome, John!
  • Anna Alexander joined LANL as a postdoctoral associate from being our academic collaborator. Welcome, Anna!

January

  • Vitaly Pavlenko was awarded competitave early career research grant at LANL on automated growth of photocathodes for accelerator beam source. The project will run for 2 years. Congratulations, Vitaly!
  • Kevin Jensen of Naval Research Laboratory visited LANL for meetings. Thank you for coming!

October

  • Our paper on perspectives on designer photocathodes was published in Physical Review Applied https://doi.org/10.1103/PhysRevApplied.10.047002. Congratulations, Nathan and Kevin!
  • LANL hosted Photocathode Physics for Photoinjectors Workshop (P3) at Hilton Santa Fe Buffalo Thunder Resort and Spa, NM. Dates were October 15-17 with a conference website here. It was a success with state-of-the-art research results and active interactions!
  • Hisato visited our collaborators in Japan at the High Energy Accelerator Research Organization (KEK) for the DOE U.S.-Japan Science and Technology Cooperation Program in High Energy Physics project. They had fruitful discussion on future plans!
Group 2018 Featured Body

 

 
September

  • Our work on free-standing bialkali photocathodes using atomically thin substrates published in Advanced Materials Interfaces was featured in September 2018 issue of Los Alamos National Laboratory Science Highlights. Click here.
  • Our work on free-standing bialkali photocathodes using atomically thin substrates published in Advanced Materials Interfaces was press released by our contributor's institution, Argonne National Laboratory. Click here.

June

  • Our paper on overcoming the quantum efficiency-lifetime tradeoff of photocathodes by coating with atomically thin two-dimensional nanomaterials was published in Nature Partner Journal (npj) 2D Materials and Applications https://doi.org/10.1038/s41699-018-0062-6. Congratulations, Gaoxue and Enrique!

May

  • Our proposal for the DOE U.S.-Japan Science and Technology Cooperation Program in High Energy Physics [LAB 18-1802] on overcoming quantum efficiency-lifetime limit of photocathodes for accelerator beam source by integration of atomically-thin protecting layers has been awarded. The lead U.S. and Japanese institutions are LANL and the High Energy Accelerator Research Organization (KEK), respectively. Congratulations, Hisato!

April

  • Our paper on free-standing bialkali photocathodes using atomically thin substrates was published in Advanced Materials Interfaces https://doi.org/10.1002/admi.201800249 and selected as the back cover https://doi.org/10.1002/admi.201870065 as well as being featured in LANL Mesoscale Connections Spring 2018 Issue. Congratulations, Hisato and Fangze!
Ami Featured Body

 

February

  • Our paper on analytical models of transmission probabilities for electron sources was published in Journal of Applied Physics https://doi.org/10.1063/1.5018602. Congratulations, Kevin!

January

  • Our paper on Photoemission Moments Model using Density Functional and Transfer Matrix Methods Applied to Coating Layers on Surfaces: Theory was published in Journal of Applied Physics DOI: 10.1063/1.5008600. Congratulations, Kevin!

June

  • Our paper on active bialkali photocathodes on free-standing graphene substrates was published in Nature Partner Journal (npj) 2D Materials and Applications DOI:10.1038/s41699-017-0014-6. Congratulations, Hisato and Fangze!

March

  • Final review of our LANL internal three-year project on photocathode development for accelerator beam source was a success!

October

  • Majority of team members presented at Photocathode Physics for Photoinjectors conference that was held at Thomas Jefferson National Accelerator Facility, Newport News, VA during October 17-19.

September

  • Applied Cathode Enhancement and Robustness Technology (ACERT) was awarded Los Alamos National Laboratory 2015 Distinguished Performance Award for Large Teams. Our contributions was evaluated highly for its dedication, effort, and outstanding, sustained performance that helped support Los Alamos National Laboratory's transformational science in a safe, secure workplace.
Acert Team 2017 Featured Body

February

  • Our project website is open!

January

  • Our academic collaborator Prof. Prabhakar Bandarus and Anna Alexander from UC San Diego visited LANL to join us for our bi-weekly project meeting. Thank you for visiting!

September

  • Our LANL internal three-year project on photocathode development for accelerator beam source has started and had our kick-off meeting!
  • Nathan Moody's patent US 8,823,259 on graphene protection of photocathodes for accelerator beam source was granted.

Publications

  • Fangze Liu*, Lei Guo, Jeffrey DeFazio, Vitaly Pavlenko, Masahiro Yamamoto, Nathan A Moody, Hisato Yamaguchi* "Photoemission from Bialkali Photocathodes through an Atomically Thin Protection Layer" ACS Applied Materials & Interfaces 14, 1710–1717 (2022). https://pubs.acs.org/doi/full/10.1021/acsami.1c19393
  • Vitaly Pavlenko, John Smedley, Alexander Scheinker, Ryan L Fleming, Anna Alexander, Mark A Hoffbauer, Nathan A Moody "Stoichiometry control and automated growth of alkali antimonide photocathode films by molecular beam deposition" Applied Physics Letters 120, 091901 (2022). https://aip.scitation.org/doi/full/10.1063/5.0080948
  • Lei Guo, Hisato Yamaguchi, Masahiro Yamamoto, Fumihiko Matsui, Gaoxue Wang, Fangze Liu, Ping Yang, Enrique R Batista, Nathan A Moody, Yoshifumi Takashima, Masahiro Katoh "Graphene as reusable substrate for bialkali photocathodes" Applied Physics Letters 116, 251903 (2020). https://aip.scitation.org/doi/full/10.1063/5.0010816
  • Gaoxue Wang, Ping Yang, Enrique R Batista "Computational screening of two-dimensional coatings for semiconducting photocathodes" Physical Review Materials 4, 024001 (2020). https://journals.aps.org/prmaterials/abstract/10.1103/PhysRevMaterials.4.024001
  • Kevin L Jensen, Andrew Shabaev, Samuel G Lambrakos, Daniel Finkenstadt, John J Petillo, Anna M Alexander, John Smedley, Nathan A Moody, Hisato Yamaguchi, Fangze Liu, Amanda J Neukirch, Sergei Tretiak "An extended moments model of quantum efficiency for metals and semiconductors" Journal of Applied Physics 128, 015301 (2020). https://aip.scitation.org/doi/full/10.1063/5.0011145
  • Alisha D Vira, Philip A Fernandes, Herbert O Funsten, Steven K Morley, Hisato Yamaguchi, Fangze Liu, Nathan A Moody "Angular scattering of protons through ultrathin graphene foils: Application for time-of-flight instrumentation" Review of Scientific Instruments 91, 033302 (2020). https://aip.scitation.org/doi/full/10.1063/1.5134768
  • Shuichi Ogawa*, Hisato Yamaguchi*, Edward F Holby, Takatoshi Yamada*, Akitaka Yoshigoe, Yuji Takakuwa "Gas Barrier Properties of Chemical Vapor-Deposited Graphene to Oxygen Imparted with Sub-electronvolt Kinetic Energy" The Journal of Physical Chemistry Letters 11, 9159–9164 (2020). https://pubs.acs.org/doi/full/10.1021/acs.jpclett.0c02112
    • Selected as an inside cover
  • Hisato Yamaguchi*, Fangze Liu, Jeffrey DeFazio, Mengjia Gaowei, Lei Guo, Anna Alexander, Seong In Yoon, Chohee Hyun, Matthew Critchley, John Sinsheimer, Vitaly Pavlenko, Derek Strom, Kevin L Jensen, Daniel Finkenstadt, Hyeon Suk Shin, Masahiro Yamamoto, John Smedley, Nathan A Moody "Quantum efficiency enhancement of bialkali photocathodes by an atomically thin layer on substrates" physica status solidi (a) (2019). https://doi.org/10.1002/pssa.201900501
    • Selected as the front cover  https://doi.org/10.1002/pssa.201970076
  • Hisato Yamaguchi and Nathan A. Moody "Atomic Armor: R&D 100 Award Winner" LANL Science Video (2019). https://www.youtube.com/watch?v=S4krKYGUopg
  • Hisato Yamaguchi and Nathan A. Moody "Atomic Armor for accelerator technology: 2D Shield for photocathodes" Science Animation (2019). https://www.youtube.com/watch?v=rkusTI_45o0
  • Kevin L Jensen, Michael McDonald, Oksana Chubenko, John R Harris, Donald A Shiffler, Nathan A Moody, John J Petillo, Aaron J Jensen "Thermal-field and photoemission from meso-and micro-scale features: Effects of screening and roughness on characterization and simulation" Journal of Applied Physics 125, 234303 (2019). https://aip.scitation.org/doi/full/10.1063/1.5097149
  • Nathan A. Moody, Kevin L. Jensen, Andrew Shabaev, Samuel G. Lambrakos, John Smedley, Daniel Finkenstadt, Jeffrey M. Pietryga, Petr M. Anisimov, Vitaly Pavlenko, Enrique R. Batista, John W. Lewellen, Fangze Liu, Gautam Gupta, Aditya Mohite, Hisato Yamaguchi, Mark A. Hoffbauer, and Istvan Robel "Perspectives on designer photocathodes: influencing emission properties with heterostructures and nano-engineered electronic states" Physical Review Applied 10, 047002 (2018). https://doi.org/10.1103/PhysRevApplied.10.047002
  • H.Yamaguchi*, F.Liu, J.DeFazio, M.Gaowei, C.W.Narvaez Villarrubia, J.Xie, V.Pavlenko, K.L.Jensen, J.Smedley, A.D.Mohite, N.A.Moody* "Free-standing bialkali photocathodes using atomically thin substrates" Advanced Materials Interfaces 5, 1800249 (2018). https://doi.org/10.1002/admi.201800249
    • Selected as the back cover  https://doi.org/10.1002/admi.201870065
    • Featured in LANL Science Highlights, LANL Science Briefs, LANL Mesoscale Connections Spring 2018, LANL Today (Internal), LANL Top News (Internal)
  • Gaoxue Wang, Ping Yang, Nathan A. Moody & Enrique R. Batista "Overcoming the quantum efficiency-lifetime tradeoff of photocathodes by coating with atomically thin two-dimensional nanomaterials" Nature Partner Journals (npj) 2D Materials and Applications 2, 17 (2018). https://doi.org/10.1038/s41699-018-0062-6
  • Kevin L. Jensen, Daniel Finkenstadt, Donald A. Shiffler, Andrew Shabaev, Samuel G. Lambrakos, Nathan A. Moody, and John J. Petillo "Analytical models of transmission probabilities for electron sources" Journal of Applied Physics 123, 065301 (2018). https://doi.org/10.1063/1.5018602
  • K.L.Jensen, D.Finkenstadt, A.Shabaev, S.G.Lambrakos, N.A.Moody, J.J.Petillo, H.Yamaguchi, and F.Liu "A Photoemission Moments Model using Density Functional and Transfer Matrix Methods Applied to Coating Layers on Surfaces: Theory" Journal of Applied Physics 123, 045301 (2018). DOI: 10.1063/1.5008600
  • H.Yamaguchi*, F.Liu, J.DeFazio, C.W.Narvaez Villarrubia, D.Finkenstadt, A.Shabaev, K.L.Jensen, V.Pavlenko, M.Mehl, S.Lambrakos, G.Gupta, A.D.Mohite, N.A.Moody* "Active bialkali photocathodes on free-standing graphene substrates" Nature Partner Journals (npj) 2D Materials and Applications 1, 12 (2017). DOI: 10.1038/s41699-017-0014-6
  • Gaoxue Wang, Ravindra Pandey, Nathan A. Moody, and Enrique R. Batista "Degradation of alkali-based photocathodes from exposure to residual gases: A first-principles study" J. Phys. Chem. C 121, 8399 (2017). DOI: 10.1021/acs.jpcc.6b12796
  • N. S. Makarov, J. Lim, Q. Lin, J. W. Lewellen, N. A. Moody, I. Robel, J. M. Pietryga "Quantum Dot Thin-Films as Rugged, High-Performance Photocathodes" Nano Lett. (2017). DOI: 10.1021/acs.nanolett.6b05175
  • Anna Alexander, Nathan A. Moody, and Prabhakar R. Bandaru "Enhanced photocathode performance through optimization of film thickness and substrate" Journal of Vacuum Science & Technology B 35, 022202 (2017). doi: http://dx.doi.org/10.1116/1.4976527
  • Fangze Liu, Nathan A. Moody, Kevin L. Jensen, Vitaly Pavlenko, Claudia W. Narvaez Villarrubia, Aditya D. Mohite, and Gautam Gupta "Single layer graphene protective gas barrier for copper photocathodes" Appl. Phys. Lett. 110, 041607 (2017). doi: 10.1063/1.4974738
  • Kevin L. Jensen, John J. Petillo, Dimitrios N. Panagos, Serguei Ovtchinnikov, Nathan A. Moody "Delayed photo-emission model for beam optics codes" Journal of Vacuum Science & Technology B 35 (2017). doi: 10.1116/1.4968511
  • Vitaly Pavlenko, Fangze Liu, Mark A. Hoffbauer, Nathan A. Moody, and Enrique R. Batista "Kinetics of alkali-based photocathode degradation" AIP Advances 6, 10.1063/1.4967349 (2016), doi: 10.1063/1.4967349
  • Anna Alexander, Nathan A. Moody, and Prabhakar R. Bandaru "Enhanced quantum efficiency of photoelectron emission, through surface textured metal electrodes" Journal of Vacuum Science & Technology A 34, 021401 (2016), doi: 10.1116/1.4936082
  • Ulises Martinez, Joseph H. Dumont, Edward F. Holby, Kateryna Artyushkova, Geraldine M. Purdy, Akhilesh Singh, Nathan H. Mack, Plamen Atanassov, David A. Cullen, Karren L. More, Manish Chhowalla, Piotr Zelenay, Andrew M. Dattelbaum, Aditya D. Mohite and Gautam Gupta "Critical role of intercalated water for electrocatalytically active nitrogen-doped graphitic systems" Science Advances 3, e1501178 (2016). DOI: 10.1126/sciadv.1501178
  • B. E. Carlsten, S. J. Russell, J. W. Lewellen, D. C. Nguyen, P. M. Anisimov, C. E. Buechler, K. A. Bishofberger, L. D. Duffy, F. L. Krawczyk, Q. R. Marksteiner, N. A. Moody, N. Yampolsky, and R. L. Sheffield "MaRIE XFEL physics design risks and risk mitigation plans" DOE Contract Number: AC52-06NA25396 (2015).
  • Wanyi Nie, Gautam Gupta, Brian K. Crone, Feilong Liu, Darryl L. Smith, P. Paul Ruden, Cheng-Yu Kuo, Hsinhan Tsai, Hsing-Lin Wang, Hao Li, Sergei Tretiak and Aditya D. Mohite "Interface Design Principles for High-Performance Organic Semiconductor Devices" Advanced Science 2,1500024 (2015). DOI: 10.1002/advs.201500024
  • J. W. Lewellen and N. A. Moody "High gradient cathode testing for MaRIE" Proceedings for FEL2014, THP024 (2014).
  • N. A. Moody, H. Yamaguchi, G. Gupta, A. D. Mohite "Graphene shield-enhancement of photosensitive surfaces and devices" Proc. SPIE, Micro- and Nanotechnology Sensors, Systems, and Applications VI, 908333 (2014). doi: 10.1117/12.2052963
  • H.Yamaguchi*, Jimmy Granstrom, Wanyi Nie, Hossein Sojoudi, Takeshi Fujita, Damien Voiry, Mingwei Chen, Gautam Gupta, Aditya D. Mohite, Samuel Graham, and Manish Chhowalla* "Reduced Graphene Oxide Thin Films as Ultrabarriers for Organic Electronics" Adv. Energy Mater. 4, 1300986 (2014). *corresponding authors DOI: 10.1002/aenm.201300986

Presentations

Nathan A. Moody
Department of Energy (DOE)
Decadal Roadmap: NCRF Injector Technologies 2017
https://portal.slac.stanford.edu/sites/conf_public/pages/default.aspx

  • Nathan A. Moody
    Department of Energy (DOE) Decadal Roadmap: Future Electron Sources Workshop 2016
    https://portal.slac.stanford.edu/sites/conf_public/fesw2016/Pages/default.aspx
  • John Lewellen
    "Motivation for photocathode source development"
    Photocathode Physics for Photoinjectors
    Thomas Jefferson National Accelerator Facility, Newport News, VA
    October 17-19, 2016
    https://www.jlab.org/conferences/p3-2016/
  • Nathan A. Moody
    "LANL Updates and Quantum Dots: photoemission from quantized energy states"
    Photocathode Physics for Photoinjectors
    Thomas Jefferson National Accelerator Facility, Newport News, VA
    October 17-19, 2016
  • Kevin Jensen (Naval Research Laboratory)
    "Transfer Matrix Methods"
    Photocathode Physics for Photoinjectors
    Thomas Jefferson National Accelerator Facility, Newport News, VA
    October 17-19, 2016
  • Andrew Shabaev (Naval Research Laboratory)
    "DFT and Graded Composition, Heterostructures and Graphene"
    Photocathode Physics for Photoinjectors
    Thomas Jefferson National Accelerator Facility, Newport News, VA
    October 17-19, 2016
  • Andrew Shabaev (Naval Research Laboratory)
    "Quantum Dots Tutorial"
    Photocathode Physics for Photoinjectors
    Thomas Jefferson National Accelerator Facility, Newport News, VA
    October 17-19, 2016
  • Daniel Finkenstadt (United States Naval Academy)
    "DFT-Calculated Properties of Graphene Shield Enhanced Photocathodes"
    Photocathode Physics for Photoinjectors
    Thomas Jefferson National Accelerator Facility, Newport News, VA
    October 17-19, 2016
  • John Lewellen
    "Diagnostics and Interchange Capabilities for Advanced Cathodes" (Poster)
    Photocathode Physics for Photoinjectors
    Thomas Jefferson National Accelerator Facility, Newport News, VA
    October 17-19, 2016
  • Aditya D. Mohite
    "Graphene shield-enhancement of photosensitive surface and devices" (Poster)
    Photocathode Physics for Photoinjectors
    Thomas Jefferson National Accelerator Facility, Newport News, VA
    October 17-19, 2016
  • Vitaly Pavlenko
    "Alkali-based Photocathode Degradation: Role of Adsorption via Kinetic Model" (Poster)
    Photocathode Physics for Photoinjectors
    Thomas Jefferson National Accelerator Facility, Newport News, VA
    October 17-19, 2016
  • Mark A. Hoffbauer
    "The ACERT Multiphysics Photocathode Growth and Characterization System" (Poster)
    Photocathode Physics for Photoinjectors
    Thomas Jefferson National Accelerator Facility, Newport News, VA
    October 17-19, 2016
  • Istvan Robel
    "Quantum Dot Photocathodes" (Poster)
    Photocathode Physics for Photoinjectors
    Thomas Jefferson National Accelerator Facility, Newport News, VA
    October 17-19, 2016
  • Finkenstadt, Daniel; Jensen, Kevin L.; Lambrakos, Samuel G.; Shabaev, Andrew; Moody, Nathan A.
    "Photoemission from Graphene on Copper and Cesium Antimonide: Theory and Experiment"
    APS March Meeting, #H26.007 (2016).
  • J. Pietryga
    "Nanocrystal quantum dots for non-traditional, high-energy applications"
    Gordon Research Conference - Nanomaterials for Applications in Energy Technology
    Ventura Beach Marriott, Ventura, CA
    February 22-27, 2015
  • N. A. Moody
    "Cathode initiatives at LANL and early results on graphene shielding for cathodes"
    Photocathode Physics for Photoinjectors
    LBNL, Berkeley
    November 3-5, 2014

Patents

  • Hisato Yamaguchi, Fangze Liu, Nathan A. Moody
    "Photocathodes with an enhancement layer and method of making the same"
    US 11,062,890 (2021).
  • Nathan Moody, Jeffrey Pietryga, Gautam Gupta, Aditya Mohite, Vitaly Pavlenko, John Lewellen, Hisato Yamaguchi
    "Photocathodes with protective in-situ graphene gas barrier films and method of making the same"
    US 10,535,486 (2020).
  • Nathan Moody, Gautam Gupta, Aditya Mohite
    "Thermionic cathode with a graphene sealing layer and method of making the same"
    US 10,679,816 (2020).
  • N. A. Moody, J. Pietryga, I. Robel
    "Tunable quantum confinement and quantum dot photocathode"
    US 10,395,882 (2019).
  • Nathan A. Moody, Mark A. Hoffbauer
    "Electron photoemission with tunable excitation and transport energetics"
    US 10,381,187 (2019).

Nathan A. Moody, David C. Lizon
"Photocathode device that replenishes photoemissive coating"
US 9,368,311 (2016).

  • Nathan A. Moody
    "Graphene Shield Enhanced Photocathodes and Methods for Making the Same"
    Publication number: US 8,823,259
    Grant date: Sept. 2, 2014
    Priority date: May 7, 2012