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Title: Free-Standing Bialkali Photocathodes Using Atomically Thin Substrates

Abstract

This study reports successful deposition of high quantum efficiency (QE) bialkali antimonide K2CsSb photocathodes on graphene films. The results pave the way for an ultimate goal of encapsulating technologically relevant photocathodes for accelerator technology with an atomically thin protecting layer to enhance lifetime while minimizing QE losses. A QE of 17% at approximate to 3.1 eV (405 nm) is the highest value reported so far on graphene substrates and is comparable to that obtained on stainless steel and nickel reference substrates. The spectral responses of the photocathodes on graphene exhibit signature features of K2CsSb including the characteristic absorption at approximate to 2.5 eV. Materials characterization based on X-ray fluorescence and X-ray diffraction reveals that the composition and crystal quality of these photocathodes deposited on graphene is comparable to those deposited on a reference substrate. Quantitative agreement between optical calculations and QE measurements for the K2CsSb on free suspended graphene and a graphene-coated metal substrate further confirms the high-quality interface between the photocathodes and graphene. Finally, a correlation between the QE and graphene quality as characterized by Raman spectroscopy suggests that a lower density of atomistic defects in the graphene films leads to higher QE of the deposited K2CsSb photocathodes.

Authors:
 [1];  [1];  [2];  [3];  [1];  [4];  [3];  [5];  [6];  [7];  [3];  [1];  [6]
  1. MPA-11 Materials Synthesis and Integrated Devices (MSID), Materials Physics and Applications Division, Mail Stop: K763, Los Alamos National Laboratory, P. O. Box 1663 Los Alamos NM 87545 USA
  2. Photonis USA Pennsylvania Inc., 1000 New Holland Ave. Lancaster PA 17601 USA
  3. Brookhaven National Laboratory, P. O. Box 5000 Upton NY 11973 USA
  4. Argonne National Laboratory, 9700 South Cass Ave. Argonne IL 60439 USA
  5. Max Planck Institute for Physics, Föhringer Ring 6 D-80805 Munich Germany
  6. Accelerators and Electrodynamics (AOT-AE), Accelerator Operations and Technology Division, Mail Stop: H851, Los Alamos National Laboratory, P. O. Box 1663 Los Alamos NM 87545 USA
  7. Materials and Systems Branch (Code 6360), Materials Science and Technology Division, Naval Research Laboratory, Washington DC 20375 USA
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1481182
DOE Contract Number:  
AC02-06CH11357
Resource Type:
Journal Article
Journal Name:
Advanced Materials Interfaces
Additional Journal Information:
Journal Volume: 5; Journal Issue: 13; Journal ID: ISSN 2196-7350
Publisher:
Wiley-VCH
Country of Publication:
United States
Language:
English
Subject:
accelerator technology; antimonide photocathodes; bialkali; gas barrier; graphene

Citation Formats

Yamaguchi, Hisato, Liu, Fangze, DeFazio, Jeffrey, Gaowei, Mengjia, Narvaez Villarrubia, Claudia W., Xie, Junqi, Sinsheimer, John, Strom, Derek, Pavlenko, Vitaly, Jensen, Kevin L., Smedley, John, Mohite, Aditya D., and Moody, Nathan A. Free-Standing Bialkali Photocathodes Using Atomically Thin Substrates. United States: N. p., 2018. Web. doi:10.1002/admi.201800249.
Yamaguchi, Hisato, Liu, Fangze, DeFazio, Jeffrey, Gaowei, Mengjia, Narvaez Villarrubia, Claudia W., Xie, Junqi, Sinsheimer, John, Strom, Derek, Pavlenko, Vitaly, Jensen, Kevin L., Smedley, John, Mohite, Aditya D., & Moody, Nathan A. Free-Standing Bialkali Photocathodes Using Atomically Thin Substrates. United States. doi:10.1002/admi.201800249.
Yamaguchi, Hisato, Liu, Fangze, DeFazio, Jeffrey, Gaowei, Mengjia, Narvaez Villarrubia, Claudia W., Xie, Junqi, Sinsheimer, John, Strom, Derek, Pavlenko, Vitaly, Jensen, Kevin L., Smedley, John, Mohite, Aditya D., and Moody, Nathan A. Tue . "Free-Standing Bialkali Photocathodes Using Atomically Thin Substrates". United States. doi:10.1002/admi.201800249.
@article{osti_1481182,
title = {Free-Standing Bialkali Photocathodes Using Atomically Thin Substrates},
author = {Yamaguchi, Hisato and Liu, Fangze and DeFazio, Jeffrey and Gaowei, Mengjia and Narvaez Villarrubia, Claudia W. and Xie, Junqi and Sinsheimer, John and Strom, Derek and Pavlenko, Vitaly and Jensen, Kevin L. and Smedley, John and Mohite, Aditya D. and Moody, Nathan A.},
abstractNote = {This study reports successful deposition of high quantum efficiency (QE) bialkali antimonide K2CsSb photocathodes on graphene films. The results pave the way for an ultimate goal of encapsulating technologically relevant photocathodes for accelerator technology with an atomically thin protecting layer to enhance lifetime while minimizing QE losses. A QE of 17% at approximate to 3.1 eV (405 nm) is the highest value reported so far on graphene substrates and is comparable to that obtained on stainless steel and nickel reference substrates. The spectral responses of the photocathodes on graphene exhibit signature features of K2CsSb including the characteristic absorption at approximate to 2.5 eV. Materials characterization based on X-ray fluorescence and X-ray diffraction reveals that the composition and crystal quality of these photocathodes deposited on graphene is comparable to those deposited on a reference substrate. Quantitative agreement between optical calculations and QE measurements for the K2CsSb on free suspended graphene and a graphene-coated metal substrate further confirms the high-quality interface between the photocathodes and graphene. Finally, a correlation between the QE and graphene quality as characterized by Raman spectroscopy suggests that a lower density of atomistic defects in the graphene films leads to higher QE of the deposited K2CsSb photocathodes.},
doi = {10.1002/admi.201800249},
journal = {Advanced Materials Interfaces},
issn = {2196-7350},
number = 13,
volume = 5,
place = {United States},
year = {2018},
month = {4}
}