Ultrafast Graphene Light Emitters

Young Duck Kim, Yuanda Gao, Ren Jye Shiue, Lei Wang, Ozgur Burak Aslan, Myung Ho Bae, Hyungsik Kim, Dongjea Seo, Heon Jin Choi, Suk Hyun Kim, Andrei Nemilentsau, Tony Low, Cheng Tan, Dmitri K. Efetov, Takashi Taniguchi, Kenji Watanabe, Kenneth L. Shepard, Tony F. Heinz, Dirk Englund, James Hone

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31 Citations (Scopus)

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, 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.

Original languageEnglish
Pages (from-to)934-940
Number of pages7
JournalNano letters
Volume18
Issue number2
DOIs
Publication statusPublished - 2018 Feb 14

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All Science Journal Classification (ASJC) codes

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

Cite this

Kim, Y. D., Gao, Y., Shiue, R. J., Wang, L., Aslan, O. B., Bae, M. H., Kim, H., Seo, D., Choi, H. J., Kim, S. H., Nemilentsau, A., Low, T., Tan, C., Efetov, D. K., Taniguchi, T., Watanabe, K., Shepard, K. L., Heinz, T. F., Englund, D., & Hone, J. (2018). Ultrafast Graphene Light Emitters. Nano letters, 18(2), 934-940. https://doi.org/10.1021/acs.nanolett.7b04324