Cesium intercalation of graphene: A 2D protective layer on alkali antimonide photocathode
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 photocath...
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| Format: | Article |
| Language: | English |
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AIP Publishing LLC
2022-11-01
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| Series: | APL Materials |
| Online Access: | http://dx.doi.org/10.1063/5.0122937 |
| _version_ | 1797947405938720768 |
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| author | Jyoti Biswas Mengjia Gaowei Ao Liu Shashi Poddar Liliana Stan John Smedley Jerzy T. Sadowski Xiao Tong |
| author_facet | Jyoti Biswas Mengjia Gaowei Ao Liu Shashi Poddar Liliana Stan John Smedley Jerzy T. Sadowski Xiao Tong |
| author_sort | Jyoti Biswas |
| collection | DOAJ |
| description | 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-ray 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 Cs3Sb. |
| first_indexed | 2024-04-10T21:27:15Z |
| format | Article |
| id | doaj.art-7dba0a1bca2f482eabf84ca968e789d5 |
| institution | Directory Open Access Journal |
| issn | 2166-532X |
| language | English |
| last_indexed | 2024-04-10T21:27:15Z |
| publishDate | 2022-11-01 |
| publisher | AIP Publishing LLC |
| record_format | Article |
| series | APL Materials |
| spelling | doaj.art-7dba0a1bca2f482eabf84ca968e789d52023-01-19T16:28:28ZengAIP Publishing LLCAPL Materials2166-532X2022-11-011011111115111115-710.1063/5.0122937Cesium intercalation of graphene: A 2D protective layer on alkali antimonide photocathodeJyoti Biswas0Mengjia Gaowei1Ao Liu2Shashi Poddar3Liliana Stan4John Smedley5Jerzy T. Sadowski6Xiao Tong7Brookhaven National Laboratory, Upton, New York 11973, USABrookhaven National Laboratory, Upton, New York 11973, USAEuclid Techlabs, Bolingbrook, Illinois 60440, USAEuclid Techlabs, Bolingbrook, Illinois 60440, USAArgonne National Laboratory, Lemont, Illinois 60439, USASLAC National Accelerator Laboratory, Menlo Park, California 94025, USABrookhaven National Laboratory, Upton, New York 11973, USABrookhaven National Laboratory, Upton, New York 11973, USAAlkali 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-ray 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 Cs3Sb.http://dx.doi.org/10.1063/5.0122937 |
| spellingShingle | Jyoti Biswas Mengjia Gaowei Ao Liu Shashi Poddar Liliana Stan John Smedley Jerzy T. Sadowski Xiao Tong Cesium intercalation of graphene: A 2D protective layer on alkali antimonide photocathode APL Materials |
| title | Cesium intercalation of graphene: A 2D protective layer on alkali antimonide photocathode |
| title_full | Cesium intercalation of graphene: A 2D protective layer on alkali antimonide photocathode |
| title_fullStr | Cesium intercalation of graphene: A 2D protective layer on alkali antimonide photocathode |
| title_full_unstemmed | Cesium intercalation of graphene: A 2D protective layer on alkali antimonide photocathode |
| title_short | Cesium intercalation of graphene: A 2D protective layer on alkali antimonide photocathode |
| title_sort | cesium intercalation of graphene a 2d protective layer on alkali antimonide photocathode |
| url | http://dx.doi.org/10.1063/5.0122937 |
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