Studies of ultrafast photocarrier dynamics in spatially heterogeneous transition metal dichalcogenides using time-resolved photoemission electron microscopy
Transition metal dichalcogenides (TMDs) are among some of the most popular two-dimensional materials. Different from graphene, TMDs have intrinsic bandgaps, which open the door for their application in a variety of ultrathin semiconductor devices. The fabrication of TMDs result in diverse spatial he...
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| Format: | Thesis-Doctor of Philosophy |
| Language: | English |
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Nanyang Technological University
2021
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| Online Access: | https://hdl.handle.net/10356/145896 |
| _version_ | 1826113214245502976 |
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| author | Xu, Ce |
| author2 | Loh Zhi Heng |
| author_facet | Loh Zhi Heng Xu, Ce |
| author_sort | Xu, Ce |
| collection | NTU |
| description | Transition metal dichalcogenides (TMDs) are among some of the most popular two-dimensional materials. Different from graphene, TMDs have intrinsic bandgaps, which open the door for their application in a variety of ultrathin semiconductor devices. The fabrication of TMDs result in diverse spatial heterogeneities in these materials, which can be either beneficial or detrimental to their properties. Therefore, it is crucial to visualize and analyze the ultrafast dynamics for a further comprehensive investigation of the alternate properties caused by the presence of heterogeneities, which can inspire defect engineering of TMD-based devices. The challenges are to achieve high spatial resolution for the observation of heterogeneities and high temporal resolution for the analysis of ultrafast dynamics at a femtosecond scale. The time-resolved photoemission electron microscopy (TR-PEEM) combines ultrafast pump-probe technique and PEEM, achieving 50-fs temporal resolution and 70-nm spatial resolution. Here, I will describe the effects of heterogeneities on the photocarrier dynamics of TMDs based on our TR-PEEM studies. |
| first_indexed | 2024-10-01T03:19:32Z |
| format | Thesis-Doctor of Philosophy |
| id | ntu-10356/145896 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T03:19:32Z |
| publishDate | 2021 |
| publisher | Nanyang Technological University |
| record_format | dspace |
| spelling | ntu-10356/1458962023-02-28T23:35:59Z Studies of ultrafast photocarrier dynamics in spatially heterogeneous transition metal dichalcogenides using time-resolved photoemission electron microscopy Xu, Ce Loh Zhi Heng School of Physical and Mathematical Sciences zhiheng@ntu.edu.sg Science::Chemistry::Physical chemistry Transition metal dichalcogenides (TMDs) are among some of the most popular two-dimensional materials. Different from graphene, TMDs have intrinsic bandgaps, which open the door for their application in a variety of ultrathin semiconductor devices. The fabrication of TMDs result in diverse spatial heterogeneities in these materials, which can be either beneficial or detrimental to their properties. Therefore, it is crucial to visualize and analyze the ultrafast dynamics for a further comprehensive investigation of the alternate properties caused by the presence of heterogeneities, which can inspire defect engineering of TMD-based devices. The challenges are to achieve high spatial resolution for the observation of heterogeneities and high temporal resolution for the analysis of ultrafast dynamics at a femtosecond scale. The time-resolved photoemission electron microscopy (TR-PEEM) combines ultrafast pump-probe technique and PEEM, achieving 50-fs temporal resolution and 70-nm spatial resolution. Here, I will describe the effects of heterogeneities on the photocarrier dynamics of TMDs based on our TR-PEEM studies. Doctor of Philosophy 2021-01-14T01:23:26Z 2021-01-14T01:23:26Z 2021 Thesis-Doctor of Philosophy Xu, C. (2021). Studies of ultrafast photocarrier dynamics in spatially heterogeneous transition metal dichalcogenides using time-resolved photoemission electron microscopy. Doctoral thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/145896 10.32657/10356/145896 en This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0). application/pdf Nanyang Technological University |
| spellingShingle | Science::Chemistry::Physical chemistry Xu, Ce Studies of ultrafast photocarrier dynamics in spatially heterogeneous transition metal dichalcogenides using time-resolved photoemission electron microscopy |
| title | Studies of ultrafast photocarrier dynamics in spatially heterogeneous transition metal dichalcogenides using time-resolved photoemission electron microscopy |
| title_full | Studies of ultrafast photocarrier dynamics in spatially heterogeneous transition metal dichalcogenides using time-resolved photoemission electron microscopy |
| title_fullStr | Studies of ultrafast photocarrier dynamics in spatially heterogeneous transition metal dichalcogenides using time-resolved photoemission electron microscopy |
| title_full_unstemmed | Studies of ultrafast photocarrier dynamics in spatially heterogeneous transition metal dichalcogenides using time-resolved photoemission electron microscopy |
| title_short | Studies of ultrafast photocarrier dynamics in spatially heterogeneous transition metal dichalcogenides using time-resolved photoemission electron microscopy |
| title_sort | studies of ultrafast photocarrier dynamics in spatially heterogeneous transition metal dichalcogenides using time resolved photoemission electron microscopy |
| topic | Science::Chemistry::Physical chemistry |
| url | https://hdl.handle.net/10356/145896 |
| work_keys_str_mv | AT xuce studiesofultrafastphotocarrierdynamicsinspatiallyheterogeneoustransitionmetaldichalcogenidesusingtimeresolvedphotoemissionelectronmicroscopy |