Phonon-assisted electronic states modulation of few-layer PdSe<inf>2</inf> at terahertz frequencies
Authors
Li, Z
Lin, ML
Leng, YC
Zhang, B
Pang, C
Publication Date
2021-11-26Journal Title
npj 2D Materials and Applications
ISSN
2397-7132
Publisher
Springer Science and Business Media LLC
Volume
5
Issue
1
Language
en
Type
Article
This Version
VoR
Metadata
Show full item recordCitation
Li, Z., Peng, B., Lin, M., Leng, Y., Zhang, B., Pang, C., Tan, P., et al. (2021). Phonon-assisted electronic states modulation of few-layer PdSe<inf>2</inf> at terahertz frequencies. npj 2D Materials and Applications, 5 (1) https://doi.org/10.1038/s41699-021-00268-3
Abstract
<jats:title>Abstract</jats:title><jats:p>Information technology demands high-speed optoelectronic devices, but going beyond the one terahertz (THz) barrier is challenging due to the difficulties associated with generating, detecting, and processing high-frequency signals. Here, we show that femtosecond-laser-driven phonons can be utilized to coherently manipulate the excitonic properties of semiconductors at THz frequencies. The precise control of the pump and subsequent time-delayed broadband probe pulses enables the simultaneous generation and detection processes of both periodic lattice vibrations and their couplings with electronic states. Combining ultralow frequency Raman spectroscopy with first-principles calculations, we identify the unique phonon mode-selective and probe-energy dependent features of electron–phonon interactions in layered PdSe<jats:sub>2</jats:sub>. Two distinctive types of coherent phonon excitations could couple preferentially to different types of electronic excitations: the intralayer (4.3 THz) mode to carriers and the interlayer (0.35 THz) mode to excitons. This work provides new insights to understand the excited-state phonon interactions of 2D materials and to achieve future applications of optoelectronic devices operating at THz frequencies.</jats:p>
Keywords
Article, /639/624/1020, /639/925/930/527/1821, /639/301/1019/385, /639/766/119/995, article
Sponsorship
Engineering and Physical Sciences Research Council (EP/P020259/1)
Identifiers
s41699-021-00268-3, 268
External DOI: https://doi.org/10.1038/s41699-021-00268-3
This record's URL: https://www.repository.cam.ac.uk/handle/1810/331436
Rights
Licence:
http://creativecommons.org/licenses/by/4.0/
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