Ultrafast Graphene Light Emitters
| Autor: | Takashi Taniguchi, Cheng Tan, Tony Low, Dongjea Seo, Suk Hyun Kim, Hyungsik Kim, James Hone, Yuanda Gao, Tony F. Heinz, Ren-Jye Shiue, Andrei Nemilentsau, Kenji Watanabe, Ozgur Burak Aslan, Young Duck Kim, Dmitri K. Efetov, Dirk Englund, Myung-Ho Bae, Heon Jin Choi, Kenneth L. Shepard, Lei Wang |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
Nanophotonics Physics::Optics Bioengineering 02 engineering and technology 01 natural sciences law.invention law Lattice (order) 0103 physical sciences Physics::Atomic and Molecular Clusters General Materials Science Emission spectrum Nanoscopic scale 010302 applied physics Graphene business.industry Mechanical Engineering Bandwidth (signal processing) General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Thermal radiation Optoelectronics 0210 nano-technology business Ultrashort pulse |
| Zdroj: | Nano letters. 18(2) |
| ISSN: | 1530-6992 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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