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Volume 7
Innovative Energy & Research
ISSN: 2576-1463
Advanced Energy Materials 2018
August 13-14, 2018
August 13-14, 2018 | Dublin, Ireland
20
th
International Conference on
Advanced Energy Materials and Research
Recent progressive of two-dimensional materials for terahertz detection
Lin Wang
1,2
, Xiaoshuang Chen
1,2
and
Wei Lu
2
1
Shanghai Institute of Technical Physics - Chinese Academy of Sciences, China
2
University of Science and Technology of China, China
R
ecent years, layered van der Waals (vdW) crystals consist of individual atomic planes weakly coupled by vdW interaction
have attracted great interests due to their intriguing physical properties, such as superconductivity, high carrier mobility,
topologically protected surface states and among many others. An ambitious practical goal is to exploit planes of vdW
crystals as building blocks of more complex optoelectronic application, especially in the terahertz band. The pursuit of two-
dimensional materials for terahertz detection is promoted by the unique properties beyond traditional system, such as good
CMOS-compatibility, easy for fabrication and fast response. Especially, graphene can support terahertz plasmon which can
lead to enhanced THz absorption. Graphene-based terahertz detectors rely on the photo thermoelectric and self-mixing effects
both of these effects depends on the near-field or the decay of plasmons. Also, other two-dimensional materials such as black
phosphorus, topological insulator exhibit exotic THz optoelectronic properties, such as anisotropic band structure in black
phosphorus (BP), interplay between surface states and bulk states such as in Bi
2
Se
3
exhibiting the unique THz spectral profile.
Initial characterization has demonstrated the excellent interaction between THz photons and two dimensional materials.
However, convent absorbed photons into electricity with high efficiency is still a big challenge. In typically, self-mixing process
for direct detection require materials with both high mobility and moderated bandgap, and is usually wipe out/disrupted by
the coexisting mechanism such as thermoelectric process. In this work, we present a new route toward manipulation of hot
electrons within high mobility materials such as BP and graphene. Due their moderated bandgap, the hot electrons in atomic
plane can be extensively excited and randomized. The unilateral flow of excess hot electrons can be facilitated by exploring
both the electromagnetic engineering and electrostatic tuning. Intriguingly, the hot electrons effect changes the resistance via
nonequilibrium carrier diffusion, leading to the high photoelectric gain under electrical bias. The present results and the novel
hot electron mechanism allow for realistic exploitation of two-dimensional materials for large area, fast imaging.
Recent Publications:
1. L Vicarelli, M S Vitiello, D Coquillat, A Lombardo, A C Ferrari, W Knap, M Polini, V Pellegrini and A Tredicucci
(2012) Graphene field-effect transistors as room-temperature terahertz detectors. Nature Materials 11:865-871.
2. Lin Wang, Changlong Liu, Xiaoshuang Chen, Jing Zhou, Weida Hu, Xiaofang Wang, Jinhua Li, Weiwei Tang, Anqi Yu
and Shao Wei Wang (2017) Toward sensitive room-temperature broadband detection from infrared to terahertz with
antenna-integrated black phosphorus photoconductor. Advanced Functional Materials 27(7):1604414.
3. Changlong Liu, Lin Wang, Xiaoshuang Chen, Jing Zhou, Weida Hu, Xinran Wang, Jinhua Li, Zhiming Huang, Wei
Zhou, Weiwei Tang, Gangyi Xu, Shao-Wei Wang and Wei Lu (2018) Room-temperature photoconduction assisted by
hot- carriers in graphene for sub-terahertz detection. Carbon 130:233-240.
Lin Wang et al., Innov Ener Res 2018, Volume 7
DOI: 10.4172/2576-1463-C1-002