Title: Cesium intercalation of graphene: A 2D protective layer on alkali antimonide photocathode

Abstract

Alkali antimonide photocathodes have wide applications in free-electron lasers and electron cooling. The short lifetime of alkali antimonide photocathodes necessitates frequent replacement of the photocathodes during a beam operation. Furthermore, exposure to mediocre vacuum causes loss of photocathode quantum efficiency due to the chemical reaction with residual gas molecules. Theoretical analyses have shown that covering an alkali antimonide photocathode with a monolayer graphene or hexagonal boron nitride protects it in a coarse vacuum environment due to the inhibition of chemical reactions with residual gas molecules. Alkali antimonide photocathodes require an ultra-high vacuum environment, and depositing a monolayer 2D material on it poses a serious challenge. In the present work, we have incorporated a novel method known as intercalation, in which alkali atoms pass through the defects of a graphene thin film to create a photocathode material underneath. Initially, Sb was deposited on a Si substrate, and a monolayer graphene was transferred on top of the Sb film. Heat cleaning around 550–600 °C effectively removed the Sb oxides, leaving metallic Sb underneath the graphene layer. Depositing Cs on top of a monolayer graphene enabled the intercalation process. Atomic force microscopy, Raman spectroscopy, x-ray photoelectron spectroscopy, low energy electron microscopy, and x-raymore » diffraction measurements were performed to evaluate photocathode formation underneath the monolayer graphene. Our analysis shows that Cs penetrated the graphene and reacted with Sb and formed Cs_3Sb.« less

Authors:

Biswas, Jyoti  ^[1];

• Search DOE PAGES for author "Biswas, Jyoti"
• Search DOE PAGES for ORCID "0000-0003-0156-3684"

Gaowei, Mengjia  ^[1];

• Search DOE PAGES for author "Gaowei, Mengjia"
• Search DOE PAGES for ORCID "0000-0001-9535-5864"

Liu, Ao ^[2]; Poddar, Shashi ^[2]; Stan, Liliana  ^[3];

• Search DOE PAGES for author "Stan, Liliana"
• Search DOE PAGES for ORCID "0000-0003-4626-7256"

Smedley, John ^[4]; Sadowski, Jerzy T.  ^[1];

• Search DOE PAGES for author "Sadowski, Jerzy T."
• Search DOE PAGES for ORCID "0000-0002-4365-7796"

Tong, Xiao ^[1]

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+ Show Author Affiliations

1. Brookhaven National Lab. (BNL), Upton, NY (United States)
2. Euclid Techlabs, Bolingbrook, IL (United States)
3. Argonne National Lab. (ANL), Lemont, IL (United States)
4. SLAC National Accelerator Lab., Menlo Park, CA (United States)

Publication Date:

Tue Nov 15 00:00:00 EST 2022

Research Org.:

Euclid Techlabs, LLC, Bolingbrook, IL (United States); Brookhaven National Laboratory (BNL), Upton, NY (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1898420

Alternate Identifier(s):

OSTI ID: 1898175; OSTI ID: 1907828

Report Number(s):

BNL-223841-2023-JAAM
Journal ID: ISSN 2166-532X; TRN: US2310898

Grant/Contract Number:  

SC0021511; SC0012704; AC02-06CH11357; AC02−76SF00515

Resource Type:

Accepted Manuscript

Journal Name:

APL Materials

Additional Journal Information:

Journal Volume: 10; Journal Issue: 11; Journal ID: ISSN 2166-532X

Publisher:

American Institute of Physics (AIP)

Country of Publication:

United States

Language:

English

Subject:

43 PARTICLE ACCELERATORS; photocathodes; intercalation; 2D materials; graphene; electron microscopy; thin films; intercalation compounds; atomic force microscopy; x-ray photoelectron spectroscopy; x-ray diffraction; ultra-high vacuum; 36 MATERIALS SCIENCE; GaAs; photocatodes; electron affinity; low energy electron microscopy