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Ultrafast electron imaging of surface charge carrier dynamics at low voltage
The performance of optoelectronic devices strongly depends on charge carrier dynamics on top of surfaces of the absorber layers. Unfortunately, this information cannot be selectively probed using conventional ultrafast laser spectroscopic methods, due to the large penetration depth (tens of nm to μm...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Crystallographic Association
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7105398/ https://www.ncbi.nlm.nih.gov/pubmed/32266302 http://dx.doi.org/10.1063/4.0000007 |
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author | Zhao, Jianfeng Bakr, Osman M. Mohammed, Omar F. |
author_facet | Zhao, Jianfeng Bakr, Osman M. Mohammed, Omar F. |
author_sort | Zhao, Jianfeng |
collection | PubMed |
description | The performance of optoelectronic devices strongly depends on charge carrier dynamics on top of surfaces of the absorber layers. Unfortunately, this information cannot be selectively probed using conventional ultrafast laser spectroscopic methods, due to the large penetration depth (tens of nm to μm) of the photon pulses in the pump-probe configurations. Therefore, ultrafast time-resolved approaches that can directly and selectively visualize the behavior of the surface carrier dynamics are urgently needed. Here, we introduce a novel methodology of low-voltage scanning ultrafast electron microscopy that can take ultrafast time-resolved images (snapshots) of the surface of materials at the sub-nanometer level. By this approach, the surface of the photoactive materials is optically excited and imaged, using a pulsed low-voltage electron beam (1 keV) that interacts with the surface to generate secondary electrons with an energy of a few eV, and that are emitted only from the top surface of materials, providing direct information about the carrier dynamics and the localization of electron/holes in real space and time. An outlook on the potential applications of this low voltage approach in different disciplines will also be discussed. |
format | Online Article Text |
id | pubmed-7105398 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | American Crystallographic Association |
record_format | MEDLINE/PubMed |
spelling | pubmed-71053982020-04-07 Ultrafast electron imaging of surface charge carrier dynamics at low voltage Zhao, Jianfeng Bakr, Osman M. Mohammed, Omar F. Struct Dyn Perspectives (Contributed) The performance of optoelectronic devices strongly depends on charge carrier dynamics on top of surfaces of the absorber layers. Unfortunately, this information cannot be selectively probed using conventional ultrafast laser spectroscopic methods, due to the large penetration depth (tens of nm to μm) of the photon pulses in the pump-probe configurations. Therefore, ultrafast time-resolved approaches that can directly and selectively visualize the behavior of the surface carrier dynamics are urgently needed. Here, we introduce a novel methodology of low-voltage scanning ultrafast electron microscopy that can take ultrafast time-resolved images (snapshots) of the surface of materials at the sub-nanometer level. By this approach, the surface of the photoactive materials is optically excited and imaged, using a pulsed low-voltage electron beam (1 keV) that interacts with the surface to generate secondary electrons with an energy of a few eV, and that are emitted only from the top surface of materials, providing direct information about the carrier dynamics and the localization of electron/holes in real space and time. An outlook on the potential applications of this low voltage approach in different disciplines will also be discussed. American Crystallographic Association 2020-03-30 /pmc/articles/PMC7105398/ /pubmed/32266302 http://dx.doi.org/10.1063/4.0000007 Text en © 2020 Author(s). 2329-7778/2020/7(2)/021001/7 All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Perspectives (Contributed) Zhao, Jianfeng Bakr, Osman M. Mohammed, Omar F. Ultrafast electron imaging of surface charge carrier dynamics at low voltage |
title | Ultrafast electron imaging of surface charge carrier dynamics at low voltage |
title_full | Ultrafast electron imaging of surface charge carrier dynamics at low voltage |
title_fullStr | Ultrafast electron imaging of surface charge carrier dynamics at low voltage |
title_full_unstemmed | Ultrafast electron imaging of surface charge carrier dynamics at low voltage |
title_short | Ultrafast electron imaging of surface charge carrier dynamics at low voltage |
title_sort | ultrafast electron imaging of surface charge carrier dynamics at low voltage |
topic | Perspectives (Contributed) |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7105398/ https://www.ncbi.nlm.nih.gov/pubmed/32266302 http://dx.doi.org/10.1063/4.0000007 |
work_keys_str_mv | AT zhaojianfeng ultrafastelectronimagingofsurfacechargecarrierdynamicsatlowvoltage AT bakrosmanm ultrafastelectronimagingofsurfacechargecarrierdynamicsatlowvoltage AT mohammedomarf ultrafastelectronimagingofsurfacechargecarrierdynamicsatlowvoltage |