Title: Ultrafast Graphene Light Emitters

Abstract

Ultrafast electrically driven nanoscale light sources are critical components in nanophotonics. Compound semiconductor-based light sources for the nanophotonic platforms have been extensively investigated over the past decades. However, monolithic ultrafast light sources with a small footprint remain a challenge. Here in this paper, we demonstrate electrically driven ultrafast graphene light emitters that achieve light pulse generation with up to 10 GHz bandwidth across a broad spectral range from the visible to the near-infrared. The fast response results from ultrafast charge-carrier dynamics in graphene and weak electron-acoustic phonon-mediated coupling between the electronic and lattice degrees of freedom. We also find that encapsulating graphene with hexagonal boron nitride (hBN) layers strongly modifies the emission spectrum by changing the local optical density of states, thus providing up to 460% enhancement compared to the gray-body thermal radiation for a broad peak centered at 720 nm. Furthermore, the hBN encapsulation layers permit stable and bright visible thermal radiation with electronic temperatures up to 2000 K under ambient conditions as well as efficient ultrafast electronic cooling via near-field coupling to hybrid polaritonic modes under electrical excitation. These high-speed graphene light emitters provide a promising path for on-chip light sources for optical communications and other optoelectronic applications.

Authors:

Kim, Young Duck  ^[1];

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• Search DOE PAGES for ORCID "0000-0003-2593-9826"

Gao, Yuanda ^[2]; Shiue, Ren-Jye ^[3]; Wang, Lei  ^[4];

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• Search DOE PAGES for ORCID "0000-0002-1919-9107"

Aslan, Ozgur Burak  ^[5];

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• Search DOE PAGES for ORCID "0000-0002-0925-3026"

Bae, Myung-Ho ^[6]; Kim, Hyungsik  ^[7];

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• Search DOE PAGES for ORCID "0000-0003-1921-4175"

Seo, Dongjea ^[8]; Choi, Heon-Jin ^[8]; Kim, Suk Hyun ^[5]; Nemilentsau, Andrei  ^[9];

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• Search DOE PAGES for ORCID "0000-0002-0895-5181"

Low, Tony  ^[9];

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• Search DOE PAGES for ORCID "0000-0002-5759-5899"

Tan, Cheng ^[10]; Efetov, Dmitri K.  ^[3];

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• Search DOE PAGES for ORCID "0000-0001-5862-0462"

Taniguchi, Takashi ^[11]; Watanabe, Kenji  ^[11];

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• Search DOE PAGES for ORCID "0000-0003-3701-8119"

Shepard, Kenneth L. ^[7]; Heinz, Tony F.  ^[5];

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• Search DOE PAGES for ORCID "0000-0003-1365-9464"

Englund, Dirk  ^[3];

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• Search DOE PAGES for ORCID "0000-0002-1043-3489"

Hone, James ^[2]

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+ Show Author Affiliations

1. Kyung Hee Univ., Seoul (Korea). Dept. of Physics
2. Columbia Univ., New York, NY (United States). Dept. of Mechanical Engineering
3. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Electrical Engineering and Computer Science
4. Kavli Inst. at Cornell for Nanoscale Science, Ithaca, New York
5. Stanford Univ., CA (United States). Dept. of Applied Physics; SLAC National Accelerator Lab., Menlo Park, CA (United States)
6. Korea Research Inst. of Standards and Science, Daejeon (Korea); Univ. of Science and Technology, Daejeon (Korea). Dept. of Nano Science
7. Columbia Univ., New York, NY (United States). Dept. of Electrical Engineering
8. Yonsei Univ., Seoul (Korea). Dept. of Materials Science and Engineering
9. Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Electrical and Computer Engineering
10. Columbia Univ., New York, NY (United States). Dept. of Mechanical Engineering; Columbia Univ., New York, NY (United States). Dept. of Electrical Engineering
11. National Inst. for Materials Science, Namiki, Tsukuba (Japan)

Publication Date:

Tue Jan 16 00:00:00 EST 2018

Research Org.:

Energy Frontier Research Centers (EFRC) (United States). Center for Excitonics (CE); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1470431

Grant/Contract Number:  

SC0001088

Resource Type:

Accepted Manuscript

Journal Name:

Nano Letters

Additional Journal Information:

Journal Volume: 18; Journal Issue: 2; Related Information: CE partners with Massachusetts Institute of Technology (lead); Brookhaven National Laboratory; Harvard University; Journal ID: ISSN 1530-6984

Publisher:

American Chemical Society

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; 42 ENGINEERING; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 77 NANOSCIENCE AND NANOTECHNOLOGY; Graphene; ultrafast light emitter; thermal radiation; van der Waals heterostructure; optoelectronics; solar (photovoltaic); solid state lighting; photosynthesis (natural and artificial); charge transport; optics; synthesis (novel materials); synthesis (self-assembly); synthesis (scalable processing)