Spatial-temporal imaging electronic dynamics in few-layer graphene
Abstract Revealing the ultrafast carrier dynamics with spatial, energy and time resolution is critical for achieving a comprehensive understanding of the ultrafast electronic dynamics of two-dimensional (2D) materials and heterostructures. Here, by time-resolved photoemission electron microscopy (Tr-PEEM) measurements, we reveal the layer-dependent ultrafast electronic dynamics of monolayer (1 ML), bilayer (2 ML), 4 ML graphene as well as bulk graphite. In contrast to 2 ML and thicker graphene, photo-excited electrons in 1 ML graphene relax much faster, which is attributed to the unique massless linear Dirac cone dispersion, allowing electrons to relax by continuously emitting phonons. Moreover, transient photoelectron redistribution shows an energy shift between 1 ML and 2 ML graphene, highlighting the critical role of the bandgap in 2 ML graphene on the carrier relaxation dynamics. Our work demonstrates the power of Tr-PEEM in revealing the ultrafast dynamics of 2D materials and heterostructures with spatial-temporal information, and provides information for the layer-dependent ultrafast relaxation dynamics in few-layer graphene.
Authors
- Shuyun Zhou (ORCID: https://orcid.org/0000-0002-9841-8610)
- Wenhui Duan (ORCID: https://orcid.org/0000-0001-9685-2547)
- Tianyun Lin (ORCID: https://orcid.org/0000-0002-4541-7171)
- Qihuang Gong (ORCID: https://orcid.org/0000-0003-4974-6244)
- Xuanxi Cai (ORCID: https://orcid.org/0009-0004-6444-9541)
- Guowei Lü (ORCID: https://orcid.org/0000-0003-0646-6971)
- Haoyuan Zhong (ORCID: https://orcid.org/0000-0003-0453-3405)
- Changhua Bao (ORCID: https://orcid.org/0000-0002-8706-6541)
- Hong‐Yun Zhang (ORCID: https://orcid.org/0000-0002-0993-8949)
- Yulu Qin (ORCID: https://orcid.org/0009-0001-2518-1704)
- Yunquan Liu (ORCID: https://orcid.org/0000-0003-1137-7236)
- Tianshuang Sheng
- Rui Wang (ORCID: https://orcid.org/0009-0009-3413-940X)
Institutions
- Shanxi University (CN)
- Tohoku University (JP)
- Peking University (CN)
- Advanced Institute of Materials Science (JP)
- Quzhou College of Technology (CN)
- Quzhou University (CN)
- Beijing Academy of Quantum Information Sciences (CN)
- State Key Laboratory of Low-Dimensional Quantum Physics
- Tsinghua University (CN)
Publication Details
- Journal
- 2D Materials
- Published
- 2024-12-11
- DOI
- https://doi.org/10.1088/2053-1583/ad9d58
- Primary Topic
- Graphene research and applications
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Natural Science Foundation of China
- China Postdoctoral Science Foundation